Heating and hot water for the professionals
Installation and Servicing Instructions

THEMA F

THIS IS A CAT II2H3+ APPLIANCE
IN WARRANTY TECHNICAL HELPLINE

01773 828400

01773 828100
INSTALLATION AND SERVICING INSTRUCTIONS
THEMA F 23 E - THEMA F SB 18 E - THEMA F SB 23 E
Note! The boiler serial number is marked on the label attached to the inside of the boiler. Refer to the 'Introduction' section page 3 for a description of the basic functions of the boiler. To safely operate the boiler, refer to the Users Instructions.

INSTALLATION SECTION

Introduction.. Page 3 Dimensions... 3 Technical data.. 4 - 5 Boiler schematic.. 6 Fixing jig... 7 Domestic hot water system design. 7 Heating system design... 8 Piping system installation.. 8 Boiler location... 9 Boiler installation.. 10 Rear outlet flue installation.. 11 - 12 Top outlet flue installation.. 13 Electrical connection... 14 Commissioning.. 15 - 16 Safety devices... 16 Settings... 17 Changing gas type.. 17

SERVICING SECTION

Routine cleaning and inspection. Page 18 - 19 Replacement of parts.. 19 - 24 Microswitch assembly... 19 Fan... 19 Air pressure switch.. 19 Spark generator... 19 Main printed circuit board.. 19 Ignition printed circuit board.. 20 Pump... 20 Temperature/Pressure gauge.. 20 Reversing valve assembly.. 20 Reversing valve front section.. 21 Loss of water switch.. 21 Water valve or diaphragm.. 21 Gas valve... 22 Modulating coil... 22 Central heating safety valve.. 23 Heat exchanger.. 23 Expansion vessel.. 23 Boiler thermistor... 23 Overheat thermostat.. 24 Combustion chamber insulation.. 24 Ignition electrode.. 24 Flame sense electrode.. 24 Burner... 24 Burner injectors.. 24 Timeclock... 24 Schematic wiring diagram.. 25 Fault finding... 26 - 27 Spare parts... 27
Mandatory warning notice for CEE countries WARNING, this appliance is designed, approved and inspected to meet the requirements of the English market. The identification plate located on the inside of the appliance certifies the origin where the product was manufactured and the country for which it is intended. If you see any exception to this rule, please contact your nearest Saunier Duval dealer. Thank you in advance for you assistance.

INTRODUCTION

The THEMA F 23 E boiler is a wall mounted modulating combination boiler with electronic ignition providing central heating and instantaneous domestic hot water. Both the central heating and domestic hot water temperature are user adjustable from the boiler control panel. Domestic hot water demand always has priority over heating demand. The THEMA F SB 18 E and SB 23 E boilers are wall mounted modulating boilers with electronic ignition providing central heating only. The central heating temperature is user adjustable from the boiler control panel. The boilers are of the II2H3+ category for use with Natural Gas (G20) as distributed in the United Kingdom, or with Butane or Propane gas (G30/G31) with the appropriate conversion kit. Conversion kits: Conversion Part No. Natural Gas (G20) to G30/GBoilers burning LPG or similar gases MUST NOT be fitted in basements or below ground level. The boiler has a fan assisted balanced flue which both discharges the products of combustion to and draws the combustion air from the outside air.

Diagram 1

The boiler is supplied for rear outlet flue connection. Alternatively, the boiler is designed to allow the flue system to be connected to the top of the boiler, top outlet flue connection. Refer to the flue fitting instructions. Electrical components have been tested to meet the equivalent requirements of BEAB. The boiler is designed for use as part of a sealed water central heating system with fully pumped circulation. The pump, expansion vessel and associated safety devices are all fitted within the boiler. The boiler can be installed against either an external wall or on an adjacent inside wall, that is, the flue system will pass directly to the rear or to either side to the terminal fitted on the outside wall face. The installation must be carried out by a competent person in accordance with the relevant requirements of The Building Regulations, The Water Byelaws, The Building Standards (Scotland) Regulations and any applicable local regulations. Ancillary equipment A range of flue accessories are available including vertical flues, twin-pipe flues, bends etc. For further information contact your supplier.

Flow rate through heating system (I/h)

Diagram 3

BOILER SCHEMATIC
24 Ignition module Heating temperature adjuster Hot water temperature adjuster Temperature/ressure gauge Expansion vessel Pump Automatic air vent Burner Heat exchanger bleed pipe Heatexchanger Gas valve Heating and hot water thermistor Ignition electrode Overheat thermostat Flame sense electrode Loss of water pressure switch Fan Air pressure switch Gas cock

A B C D E

Heating return Cold water inlet Heating flow Domestic hot water flow Gas supply
THEMA F SB 18 E - THEMA F SB 23 E
Ignition module Heating temperature adjuster Temperature/pressure gauge Expansion vessel Pump Automatic air vent Burner Heat exchanger bleed pipe Heatexchanger Gas valve Heating and hot water thermistor Ignition electrode Overheat thermostat Flame sense electrode Loss of water pressure switch Fan Air pressure switch Gas cock

Shy 131

Diagram 4

FIXING JIG

From left to right, the fixing jig comprises: A - Heating return with isolating valve (m). B - Cold water inlet with isolating valve (p). C - Heating flow with isolating valve (q), drain screw (r) and safety valve (s). D - Domestic hot water out. E - Gas service cock.

3 A B C

Filters and washers : 1 - Washer 2 - Metal filter 3 - Flow regulator 4 - Plastic filter 5, 6 & 7 - Washers

p r q s

Pla 105c
THEMA F SB 18 THEMA F SB 23 E
From left to right, the fixing jig comprises: A - Heating return with isolating valve (m). C - Heating flow with isolating valve (q), drain screw (r) and safety valve (s). 3 E - Gas service cock. 11

m p r q s 7 E

Pla 116b

Diagram 5

DOMESTIC HOT WATER SYSTEM DESIGN
Copper tubing or plastic Hep2 O may be used for the domestic hot water system. Unnecessary pressure losses should be avoided. The boiler may operate with a minimum supply pressure of 0,3 bar but under a reduced flow rate. Optimum performance will be obtained from a supply pressure of 1 bar. The flow restrictor must be fitted in the cold water inlet during installation. This limits the flow through the boiler to a maximum of 12 l/min.

HEATING SYSTEM DESIGN

The THEMA F boiler is compatible with any type of installation. Heating surfaces may consist of radiators, convectors or fan assisted convectors. Pipe sectional areas shall be determined in accordance with normal practices, using the output/pressure curve (diagram 3). The distribution system shall be calculated in accordance with the output requirements of the actual system, not the maximum output of the boiler. However, provision shall be made to ensure sufficient flow so that the temperature difference between the flow and return pipes be less than or equal to 20C. The minimum flow is 500 l/h. The piping system shall be routed so as to avoid any air pockets and facilitate permanent venting of the installation. Bleed fittings shall be provided at every high point of the system and on all radiators. The total volume of water permitted for the heating system depends, amongst other things, on the static head in the cold condition. The expansion vessel on the boiler is pressurised at 1 bar (corresponding to a static head of 5 m w.g.) and allows a maximum system volume of 140 litres for an average temperature of 75C and a maximum service pressure of 3 bar. This pressure setting can be modified at commissioning stage if the static head differs. An additional expansion vessel can be fitted to the system if required, see diagram 6. Provision shall be made for a drain valve at the lowest point of the system. Where thermostatic radiator valves are fitted, not all radiators must be fitted with this type of valve, and in particular, where the room thermostat is installed. In the case of an existing installation, it is ESSENTIAL that the system is thoroughly flushed prior to installing the new boiler using a proprietary product such as Fernox or Sentinel. Contact the product manufacturers for specific details. Filling the system Provision must be made for filling the system at low level. The use of a WRC approved filling loop is strongly recommended, connected as shown in diagram 6.

255 mini

50 mini

Diagram 7

The boiler must be installed so that the terminal is exposed to the external air. Note: Under certain weather conditions the flue may produce a plume of condensation, this is quite normal. If the terminal is fitted within 850mm of a plastic or painted gutter or 450m of painted eaves, an aluminium shield of a minimum length of 750mm should be fitted to the underside of the gutter or painted surface. Should any doubt exist as to the permissible position of the terminal, contact the Saunier Duval Technical Helpline 01773 828400. Cupboard or compartment ventilation The boiler can be fitted in a cupboard or compartment without need for permanent ventilation.
Minimum dimensions (in mm) for the positioning of flue terminals
A - Under a window.. 300 B - Under an air vent.. 300 C - Under a gutter.. 75 D - Under a balcony.. 300 E - From an adjacent window.. 300 F - From an adjacent air vent.. 300 G - From vertical drain pipes or soil pipes. 75 H - From an external corner of the building.. 300 I - From an internal corner of the building. 300 L - From the ground or from another floor. 300 M - Between two terminals vertically.. 1500 N - Between two terminals horizontally. 300

G C E F M

A B D I H L

Diagram. 8

Ven 060b

Ins 012a

BOILER INSTALLATION
Statutory requirements The installation of this boiler must be carried out by a competent person in accordance with the relevant requirements of the current issue of: The Gas Safety (Installation and Use) Regulations The Building Regulations The local water company Byelaws The Building Standards Regulations (Scotland) The Health and Safety at Work Act Sheet metal parts WARNING. When installing or servicing this boiler, care should be taken when handling the edges of sheet metal parts to avoid the possibility of personal injury. Installing the boiler Prior to starting work, the system must be thoroughly flushed so as to eliminate any foreign bodies and contaminants such as filings, solder particles, oil, grease etc. Note. Solvent products could cause damage to the system. Note. If using a rear outlet flue system, follow the instructions in 'Rear outlet flue installation' section prior to hanging the boiler. Engage boiler upper part onto the hook, see diagram 9. Allow the boiler to seat down onto support plate, see diagram 10. Fit filter and washers, strictly adhering to the sequential order and directions shown on diagram 5. Connect the various couplings between the boiler and the connection plate.

Diagram. 10

Diagram. 9
REAR OUTLET FLUE INSTALLATION
The boiler is supplied for rear outlet flue connection. Alternatively, the boiler is designed to allow the flue system to be connected to the top of the boiler, top outlet flue connection. For top outlet flue connection, refer to 'Top outlet flue installation' Rear outlet flue - kit 86151 The rear outlet flue system consists of two parts, a white painted outer pipe and an aluminium inner, they are positively locked together when assembled. The flue kit 86151, see diagram 11, is 1000 mm long and comprises: - Outer pipe... A - Inner pipe... B - External rubber sealing collar.. C - Flue elbow.. D - Internal flange.. E - 'O' rings... F - Screws.. G - Rubber collar.. H - Clamp and seal..I - Gasket.. J

Ins 020

A - Direct rear outlet flue Mark correct position of hole from template using hole between hook and connecting plate.

Pho 422

Diagram 11

Ins 021

B - Rear outlet side flue Mark the horizontal centre line on the rear wall. Extend the horizontal centre line to the side wall and mark the vertical centre line of the flue hole as shown in diagram 12. Important: When cutting the flue hole and when extending the flue centre line to a side wall, remember that the flue system must have a fall of about 35 mm per metre of flue DOWNWARD AWAY FROM the boiler. There must NEVER be a downward incline towards the boiler. Cutting the flue hole Making allowance for the slope of the flue, cut hole in external wall, preferably using a core drill. For installations with internal and external access Use a 105 mm diameter core drill. For installations with internal access only - Use a 125 mm diameter core drill. Important: Before cutting the hole for flues to the rear of boiler, always cover fixing jig to make sure it is not damaged. Calculation of flue cutting lengths Measure wall thickness e (mm). For side flues, measure distance from inside face of side wall to centre line of flue and subtract 176 mm for right hand flue or subtract 234 for left hand flue to get dimension a (mm), see diagram 13 or 14. Refer to table 1 for cutting lengths of both inner and outer flue pipes for each of the various flue options available. Important: All flue cutting lengths must be measured from the terminal end of the flue pipes, see diagram 15. When the dimension X measured on site is greater than that given in table 1, a flue extension kit will be required, refer to table 2 for details. Refer to table 1 for the cutting lengths of both the inner and outer pipes for each of the flue options available.

Diagram 12

Diagram 13
Table 1 Flue cutting lengths
Cutting length (mm) Flue option Rear outlet Side flue to left (Diagram 13) Rear outlet Side flue to right (Diagram 14) outer pipe e + a + 96 inner pipe e + a + 173 Comments maximum distance 'X' without extension 1080 mm maximum distance 'x' without extension 1080 mm

e + a + 154

e + a +231

Hab 209

Diagram 14

Hab 208

Extended flue The horizontal flue is extended by using one or more of the 1000 mm extension pipes, Saunier Duval part number 85091. These are connected together by push fit type joints, clamps and seals. Calculation of flue cutting lengths for extended flue Using the correct number of extension kits as table 2, measure dimensions a and e, see diagram 13 or 14. Cut both the inner and outer pipe to the dimensions given in table 3. Important: All cutting lengths should be measured from the push fit end of the extension pipe. Do not leave any burrs or sharp edges on the cut ends of the pipes. Installation of flue assembly-direct rear flue Fit rubber sealing collar (C) into groove at the outer end of pipe (A), see diagram 16. Fit outer pipe (A) into wall with groove to the outside. Pull pipe inwards to bring rubber sealing collar hard up against external wall, see diagram16. Fit internal plastic flange (F) onto outer pipe. Push along the pipe until engaged against internal wall. From inside, insert inner pipe (B) into outer pipe turning anti-clockwise to allow inner to fully enter outer pipe. Fit rubber sleeve (H) onto outer pipe. Take hold of inner flue,twist clockwise and push gently onto fan outlet. Pull rubber sleeve onto boiler spigot ensuring a good seal. Installation of flue assembly-side flue Fit rubber sealing collar (C) into groove at the outer end of pipe (A), see diagram 16. Fit outer pipe (A) into wall with groove to the outside. Pull pipe inwards to bring rubber sealing collar hard up against external wall, see diagram16. Fit internal plastic flange (F) onto outer pipe. Push along the pipe until engaged against internal wall. From inside, push inner pipe (B) into outer pipe turning anti-clockwise to allow inner to fully enter outer pipe. Fit rubber sleeve (H) onto outer pipe. Fit both 'O' rings (F) into flue elbow (D), one at the inlet, one at the outlet. By necessity, they are a loose fit, apply a small amount of silicone grease to each 'O' ring when fitting. Important: If the flue has been cut, ensure that there are no burrs that could damage the 'O' ring. Remove the backing from the self adhesive gasket (J) and carefully fit gasket to base of flue elbow. Fit elbow onto boiler and secure with the four screws (G). Take hold of inner flue, twist clockwise and push gently onto the elbow outlet taking care not to tear the 'O' ring. Pull rubber sleeve onto elbow ensuring a good seal.

Diagram 15

Outer pipe

Cutting length

Inner pipe

Ven 089

Table 2 Number of extension kits required
Flue option Side flue (left or right) Dimension 'X' 1081 to 1811mm 1812 to 2542 mm No. of extension kits 1 2
Table 3 Extended flue cutting lengths
Cutting length (mm) Flue option Rear outlet Side flue to left (Diagram 13) outer pipe e + a - 906 inner pipe e + a + 829 Comments maximum distance 'X' without extension 1080 mm maximum distance 'x' without extension 1080 mm
Rear outlet Side flue to right (Diagram 14)

e + a - 848

e + a + 771

Diagram 16

Pho 087
TOP OUTLET FLUE INSTALLATION
Top outlet flue - kit 86151 see diagram 18, is 1000 mm long and comprises: - Outer pipe... A - Inner pipe.. B - External rubber sealing collar.. C - Flue elbow... D - Internal flange... E - 'O' rings.... F - Screws... G - Rubber collar... H - Clamp and seal... I - Gasket... J A - Flue to rear of boiler Mark correct position of hole from template. B - Flue to side of boiler Mark horizontal centre line for hole on rear wall. Extend horizontal centre line to side wall and mark vertical centre line of flue hole as shown in diag. 12. Under normal circumstances, it will be possible to gain access to the outside of the building to fit the flue terminal assembly. Where outside access is not possible e.g. high rise buildings, the flue terminal can be fitted from inside the building only if required. Note : When cutting flue hole and when extending flue centre line to a side wall, remember that the flue system must have a fall of about 35 mm per metre of flue DOWNWARD AWAY FROM the boiler. There must NEVER be a downward incline towards the boiler. Cutting the flue hole Making allowance for the slope of the flue, cut hole in external wall, preferably using a core drill. For installations with internal and external access - Use a 105 mm diameter core drill. For installations with internal access only - Use a 125 mm diameter core drill. Important: Before cutting hole for flues to rear of boiler, always cover fixing jig to make sure it is not damaged.

Table 1 :

Flue Cutting length (mm) Flue option outer pipe inner pipe e + a + 202 Comments maximum distance 'X' without extension 1080 mm Flue option outer pipe inner pipe e + a + 800 Comments maximum distance 'X' without extension 1080 mm Top outlet e + a + 877 Side flue to (left or right)

Diagram 17

For no external controls leave wire link (E) in place

sch 228

The mains electrical cable is supplied with the boiler. It is coiled and tucked inside the boiler

Cylinder

THEMA F SB 18 E THEMA F SB 23 E

Diagram 19

sch 227

sch 229

COMMISSIONING
The commissioning and first firing of the boiler must only be done by a competent person. Gas installation It is recommended that any air is purged from the supply at the gas inlet test point on the left hand side of the gas valve, see diagram 20. Filling the system

Diagram 20

Open shut off valves (slot of screw corresponds to flow direction).
Undo, but do not remove, cap on automatic air vent on top of pump. Do not retighten cap.
Open the tap on the system filling loop and fill the system until the pressure indicated on the display is between 1 and 2 bar.

Ins 017a

Reg 007
Important: - If this procedure is not carried out properly, the boiler will go into safety lock-out until all of the air has been purged. - When venting air from boiler, do not touch the schrader valve on the expansion vessel, it is NOT a vent. - Before starting the boiler, turn the pump impellor to make sure it is free to move. Unscrew black cap on front of pump. Using screwdriver, push in pump spindle and turn pump impellor 3 to 4 times. DO NOT HIT SPINDLE. Replace black cap. Starting the boiler Before starting the boiler check that: - The gas meter tap is open. If using Butane or Propane, check that valve on storage cylinder or tank is open. - you have removed the two fan transist clips from fan.
- The boiler gas service cock is open. - The boiler is connected to the electrical supply and switched on. - The front casing is fitted. First starting up Following the instructions given in the 'User Instructions' set boiler to run in central heating mode. Set boiler thermostat for maximum temperature and check that any external controls, if fitted, are calling for heat. Allow the temperature to rise to the maximum value, with all radiator valves open. The temperature rise will cause release of the gases contained in the water of central heating system. - Gases driven towards the boiler will be automatically released through the automatic air vents. - Gases trapped at the highest point of the system must be released by bleeding the radiators.

Sec 055

Ins 061

Ins 062

Bleed air from the heat exchanger by undoing the air bleed cap. Do not remove this cap. When all the air has been removed, tighten cap.
Bleed each radia tor until a continuous jet of water is obtained.
Open various hot water taps to bleed system.
Make sure that pressure gauge reads between 1 and 2 bar. Re-pressurise system as necessary.

Reg 008

mec 117
On reaching maximum temperature, the boiler should be turned off and the system drained as rapidly as possible whilst still hot. Refill system to a pressure of 1 bar and vent as before. Restart boiler and operate until a maximum temperature is reached. Shut down boiler and vent heating system. If necessary, top up heating system and make sure that a pressure of 1 bar is indicated on the pressure gauge when system is COLD. Gas pressures The main burner pressure should be checked during commissioning to make sure the correct input is obtained. Proceed as follows: Shut down boiler. Undo screw on burner pressure test point below sealed combustion chamber, see diagram 23. Connect a suitable pressure gauge. Gain access to the rear of the control panel and locate the range rating adjuster screw, see diagram 24. Start boiler as described in 'User Instructions'. Set boiler thermostat to maximum and check that any external controls are calling for heat. Check that the reading on the gauge matches that given in 'Technical Data' for the type of gas being used. Adjust the range rating adjuster screw as necessary to obtain the desired input. Shut down boiler. Remove pressure gauge, tighten up test point screws and check for gas soundness. Using a ball point pen, clearly indicate on the data label the input the boiler is set to. Note: This adjustment does not affect the domestic hot water output. If measured burner pressure differs greatly from the given figure, check the gas inlet pressure as follows: Shut down boiler.

microswitch on THEMA F 23 E

Diagram 29

Diagram 30
Undo and remove screw securing spark generator to bracket and remove spark generator. Fit replacement spark generator in reverse order to removal. Reconnect two grey power supply leads and two clear ignition leads to spark generator, the polarity is not important. Refit lower terminal cover. To replace main printed circuit board (PCB) With lower front panel down as described previously, undo and remove screw holding pump connection cover to PCB cover, see diagram 30. Open cover and unclip plastic clip securing pump cable to lower front panel. Pull off pump connector and earth lead. Undo and remove four screws securing PCB cover to lower front panel. Lift off PCB cover. Pull off connectors CN6, CN7, CN8 and CN9 on PCB. Undo and remove screw holding PCB to lower front panel. Lifting PCB up slightly on LHS, pull PCB out of electrical connector on ignition PCB. Leave ignition PCB in place.

Hab 286

Sch 228
Fit replacement PCB in reverse order to removal. Important: When fitting replacement PCB, ensure that control knob spindles correctly locate into PCB adjuster slots. Refit connectors and covers in reverse order to removal. To replace ignition PCB Gain access to PCB's as described in previous section. Remove main PCB securing screw as described in previous section. Pull off three electrical connectors on PCB. Lift up ignition PCB, separate from main PCB and remove from boiler. Fit replacement PCB in reverse order to removal. Refit connectors and covers in reverse order to removal. To replace pump Drain down heating circuit of boiler only as follows: Close isolating valves on flow and return connections on fixing jig, see diagram 5. Note: These valves are closed when slots are at right angles to direction of flow. It is not necessary to drain entire heating circuit to carry out this work. Drain boiler by attaching a plastic tube to drain outlet and opening drain valve knob anticlockwise, see diagram 5. Gain access to pump connection as described in 'To replace main PCB'. Pull off pump connector and earth lead. Pull out retaining clip from telescopic pump outlet connection and slide connection upwards to release from pump. Undo and remove two fixing screws and remove pump retaining bracket from front of pump. Grasp pump body, lift upward to disengage from reversing valve and turn pump to right. Remove pump by pulling forward and over reversing valve assembly. Discard old pump inlet 'O' ring. Apply silicone grease to new 'O' ring supplied, and fit onto inlet connection on replacement pump. Fit replacement pump in reverse order to removal. Note: Apply silicone grease to pump outlet connection 'O' ring before assembly. Refit pump electrical connection. Open isolating valves on flow and return connections, refill, vent and pressurise boiler. Check for leaks. To replace temperature/pressure gauge Drain down heating circuit of boiler only as described in 'To replace pump'. Undo and remove screw securing pressure gauge capillary to front section, see diagram 31. Carefully pull capillary from front section. Undo and remove two screws securing temperature/pressure gauge to lower front panel and remove gauge. Fit replacement gauge in reverse order to removal.

Diagram 31

Diagram 32
Fit capillary of new gauge to front section using new 'O' ring supplied. Open isolating valves on flow and return connections, refill, vent and pressurise boiler. Check for leaks. To replace reversing valve assembly Remove temperature/pressure gauge capillary as described previously. Remove pump as described previously. Remove microswitch assembly as described previously. Remove retaining clip from LHS pipe connection on front section of valve and disengage pipe. Unscrew and disconnect heating flow (centre) connection at fixing jig. Remove retaining clip from heating flow pipe connection on right of front section. Remove flow pipe from boiler. Unscrew and disconnect heating return (left hand) connection at fixing jig. Remove retaining clip from expansion vessel pipe connection at rear of reversing valve assembly and disengage pipe, pushing pipe back and out of reversing valve. Undo and remove large screw holding water valve to back plate of reversing valve assembly, see diagram 32.

Des 054

Cla 007
Push water valve back to disengage it from reversing valve. Unclip and remove loss of water pressure switch from left of reversing valve assembly, see diagram 33. From below boiler, undo and remove three screws holding reversing valve to bottom plate of boiler. Remove complete reversing valve assembly from boiler. Undo and remove heating return connecting pipe and hose from rear of reversing valve assembly. Fit hose to replacement reversing valve assembly. Fit replacement reversing valve into boiler in reverse order to removal. Note: Use new 'O' rings, retaining clip, filter and washer provided. Unscrew and remove microswitch assembly from top of replacement reversing valve assembly to allow refitting of water valve. Note: fit expansion vessel pipe and loss of water switch to reversing valve assembly before pump, to ensure that it is correctly located. Apply silicone grease to all 'O' rings and hoses prior to assembly. Open isolating valves on flow and return connections, refill, vent and pressurise boiler. Check for leaks. To replace reversing valve front section Remove pressure gauge capillary as described previously. Remove pipe connections from either side of reversing valve front section, refer to previous section. Move short selector lever on front of valve to left hand position. From below boiler, undo and remove single screw holding reversing valve front plate to bottom plate of boiler. Undo and remove six screws holding front section to rear section of reversing valve, see diagram 34. Remove front plate complete with pump bracket and then front section from reversing valve, along with rubber sealing gasket. Assemble bypass valve provided and fit into hole in underside of replacement front section. Fit 'U' shaped retaining clip. Note: Use bypass valve fitted to original front section for guidance. Fit replacement front section, with gasket, to rear section. Locate front plate and replace six fixing screws. Take care to evenly tighten screws ensuring they are not cross threaded. Refit pipe connections to either side of front section using new 'O' rings provided. Apply silicone grease to 'O' rings before fitting. Refit pressure gauge capillary in reverse order to removal. Ensure short selector lever on front of valve is set to right hand position. Open isolating valves on flow and return connections, refill, vent and pressurise boiler. Check for leaks.

Diagram 33

Diagram 34
To replace loss of water switch Drain down heating circuit of boiler only as described in 'To replace pump'. Note: It is not necessary to drain entire heating circuit to carry out this work. Pinch plastic cover to release retaing clips and remove cover from switch. Pull plug lead from switch terminals. Remove clip holding switch into left side of reversing valve assembly. Pull switch out of reversing valve assembly, see diagram 33. Fit replacement switch in reverse order to removal, using new 'O' ring provided and applying silicone grease to 'O' ring before fitting. Reconnect plug to switch terminals. Open isolating valves on flow and return connections, refill, vent and pressurise boiler. Check for leaks. To replace water valve or diaphragm (except SB models) Drain down hot water circuit of boiler only as described in 'Routine Cleaning and Inspection'. Remove microswitch assembly as described previously. Unscrew connecting nut from cold water inlet connection, second from left on fixing jig. Keep filter and flow regulator. Remove clip holding connecting pipe in rear of water valve. From below boiler, grip clip with long nosed pliers and pull down. Note: This connecting pipe is telescopic, it may be necessary to slide back brass sleeve to facilitate removal.

Sec 059

Remove clip holding pipe to heat exchanger in rear of water valve. From front of boiler, grip clip with long nosed pliers and pull upwards. Unscrew and remove large screw holding water valve to back plate of reversing valve assembly, see diagram 32. Disengage water valve from reversing valve and remove from boiler. Note: When disengaging water valve from heat exchanger pipe, check that non-return valve is not held on end of pipe. If so, carefully separate pipe from valve to ensure that small spring and plunger do not fly out and are lost. To replace diaphragm, undo five screws and separate main components of water valve. If white diaphragm cover is to be replaced, separate original from water valve end casting and fit replacement cover. Fit replacement diaphragm , making sure that metal disc FACES diaphragm cover and beaded edge of diaphragm is correctly fitted in corresponding groove in both cover and plastic housing, see diagram 35. Reassemble water valve, evenly tightening five screws. Fit water valve actuating pin into hole in diaphragm cover, through nose end of valve and and push in until flush, or slightly below, nose end of valve. Note: Apply silicone grease to pin before fitting. Refit water valve to boiler, locating nose end into rear of reversing valve assembly, 'springing' heat exchanger pipe to gain clearance as necessary. Fit large water valve retaining screw but do not tighten fully at this stage. Apply silicone grease to 'O' ring and fit onto end of heat exchanger pipe. Fit pipe into water valve by pulling it forward. Make sure that 'O' ring is correctly located. Whilst holding pipe in rear of water valve, fit retaining clip. This should easily clip over pipe and should NOT have to be forced. If resistance is experienced, either pipe is not correctly fitted in rear of water valve or clip is not being fitted properly through slot between back plate and plastic housing of water valve. When clip is fitted, check connection by pushing pipe back away from water valve. Refit telescopic connecting pipe to inlet of water valve after applying silicone grease to 'O' ring. Fit retaining clip into groove on connecting pipe, through slot between back plate and water valve plastic housing. Check connection by pulling pipe. Make sure that clip is not loose and likely to fall out at a later date. If in doubt, fit a new clip. With both flow regulator and and plastic filter washer in place, refit connecting nut to inlet connection and tighten. Open isolating valve on cold water inlet connection and check for leaks. Replace microswitch assembly. To replace gas valve Ensure gas supply is off. Disconnect two black electrical leads from gas valve modulating coil.

Diagram 37

Unclip thermistor from pipe. Pull off electrical cennections from thermistor. Fit replacement thermistor in reverse order to removal. Note: No heat sink compound is required. The polarity of the connections is not important. To replace overheat thermostat Locate the overheat thermostat on the right hand side of the heat exchanger. Pull off the electrical connections from the thermostat. Unscrew and remove two screws holding thermostat to heat exchanger. Fit replacement thermostat in reverse order to removal, using heat sink compound on the contact surface of thermostat. Refit electrical leads, the polarity is not important. To replace combustion chamber insulation Front section Remove combustion chamber from boiler as described in 'Routine Cleaning and Inspection'. Slide side panels out of combustion chamber sides. Lift front insulation panel free from retaining lugs and away from cover. Fit replacement panels in reverse order to removal. Rear panel Remove burner from boiler as described in 'Routine Cleaning and Inspection'. Remove clip from base of insulation panel. Pull bottom edge of insulation panel forward, downward and out from behind heat exchanger. Fit replacement panel in reverse order to removal. Replace burner into boiler in reverse order to removal. To replace ignition electrode Remove combustion chamber from boiler as described in 'Routine Cleaning and Inspection'. Pull off ignition leads from ignition electrode. Unscrew and remove two screws holding ignition electrode onto burner. Fit replacement ignition electrode in reverse order to removal. Refit ignition leads, the polarity is not important. To replace flame sense electrode Remove combustion chamber from boiler as described in 'Routine Cleaning and Inspection'. Pull off lead from flame sense electrode. Unscrew and remove screw holding earth lead to flame sense electrode. Unscrew and remove screw holding flame sense electrode onto burner. Fit replacement flame sense electrode in reverse order to removal. Refit lead. To replace burner Pull off ignition and flame sense leads from electrodes. Remove burner from boiler as described in 'Routine Cleaning and Inspection'. Remove ignition and flame sense electrodes as described in previous sections. Unscrew and remove two screws holding burner injector bar to burner and remove injector bar. Asemble replacement burner, supplied in parts, as follows: Fit burner injectors to injector bar and tighten. Assemble burner elements (14) into front and rear burner supports with securing pins and rods, using original burner for guidance. Fit burner injector bar to burner. Fit ignition and flame sense electrodes to burner. Fit replacement burner to boiler in reverse order to removal. Reconnect ignition and flame sense leads to electrodes. Reconnect earth lead to flame sense electrode. The polarity of the ignition leads is not important. To replace burner injectors Remove burner as described previously. Remove ignition and flame sense electrodes as described in previous sections. Unscrew and remove two screws holding burner injector bar to burner and remove injector bar. Unscrew and remove burner injectors from burner bar. Fit replacement injectors to injector bar and tighten. Note: make sure that injector size, marked on each injector, is the same as that given in 'Technical Data'. Reassemble burner and replace into boiler in reverse order to removal. To replace timeclock Gain access to rear of lower control panel as described in 'Routine Cleaning and Inspection'. Unscrew and remove two screws holding timeclock to lower control panel. Remove PCB cover. Remove timeclock plug from connection CN7 on main PCB. Fit replacement timeclock in reverse order to removal.

Rectify wiring operation faults on external controls
Is there continuity across terminals 3 and 4 of clock ?
Remove leaos from boiler thermistor. Check its resistance according to thermistor value table. is thermistor ok ?
Is clock calling for heat ? Replace thermistor
Is wiring between clock and pcb connection cn7 ok ?

Replace clock

Replace main pcb

CHART 1

Open hot tap fully. Does burner fire ?

NO HOT WATER

(except SB models)

PUMP NOT RUNNING

Is there 240 v at pump ?

YES YES

With selector switch/thermostat NO in position and turner to maximum. Does burner fire for CH ? Refer to chart n2

Is pump jammed ?

Is there 240 v at terminal cn2 of PCB ?

Replace pump motor

Free pump
Is there at least 3 litres/min water flow at tap ?
Check mains water supply, water filter

Replace main PCB

Check operation of water valve diaphragm. Does reversing valve mechanism move when hot tap is opened ?

Replace diaphragm

CHART 3
Is there continuity across DHW microswitch and PCB connections cn 6.4 and cn 6.9 ?

Replace dhw microswitch

FAN NOT RUNNING
Is there 240 v at fan ? Is fan jammed ?
Remove leads from boiler thermistor. Check its resistance in accordance with thermistor value table. Is thermistor ok ?

Replace thermistor

Replace fan

CHART 4

CHART 2

Termistor Values

Temperature (C) nominal resistance () for NTC Temperature (C) nominal resistance () for NTC 50 3605

SPARE PARTS

When ordering spare parts, quote the part number and description, stating the appliance model number and serial number from the data badge. Short parts list No. Description Fan Pump Spark generator Air pressure switch Main PCB (SB models) Main PCB (THEMA F 23 E) Part No. No. Description Part No. Control PCB (all models) 57277 Water valve diaphragm kit 52519 Microswitch assembly (THEMA F 23 E)51590 Temperature/pressure gauge 57278 Boiler Thermistor 57060 Overheat thermostat 51199

108198 B 06/98

Draining and Filling

Caution: The boiler is installed as part of a sealed system which must only be drained and filled by a competent person. If the mains electricity and gas are to be turned off for any long periods during severe weather, it is recommended that the whole system, including the boiler, refer to diagram 1, should be drained to avoid the risk of freezing. Make sure that, if fitted, the immersion heater in the cylinder is switched off. If in doubt, consult your servicing company.

F24E Only

If the boiler loses water: the pressure will be indicated, see diagram 1 (a) and the boiler ON indicator (b) will flash red indicating a fault. Fill the system by the filling device (c) at the bottom of the boiler until the pressure gauge reads 1.0 bar. A mains inlet pressure of 2.0 bar is required to reach a fill pressure of 1.0 bar. Reset boiler: refer to diagram 2, turn the On/Off switch to (0), wait for five seconds. Turn the On/Off switch to ( I ) to reset the appliance.

BOILER DRAIN VALVE

3.2.1.0.45 35

F18E SB Only

If the boiler loses water: the pressure will be indicated, see diagram 1 (a) and the running lamp (b) will flash red indicating a fault. Fill the system with the external filling device until the pressure gauge reads 1.0 bar. Reset boiler: refer to diagram 2, turn the On/Off switch to (0), wait for five seconds. Turn the On/Off switch to ( I ) to reset the appliance. Warning: Take care not to overfill the boiler. At a pressure of 2.5 bar or above indicating over pressure, the boiler ON indicator (b) will flash red indicating a fault. The pressure must be reduced to 1.0 bar by opening the drain valve, refer to diagram 1. If the fault continues call the relevant Servicing

Diagram 1

organisation or Saunier Duval Service using the telephone number on the inside front cover of this literature.

Appliance Introduction

The F24E and F18E SB boilers are wall mounted modulating boilers with electronic ignition providing central heating and hot water. The boiler is of the II2H3+ category and is for use with natural Gas (G20) as distributed in the United Kingdom, but can be converted to use Butane (G30), Propane (G31) with the appropriate kit. Thema Classic F24E LPG boilers are factory set for use on Butane (G30) and Propane (G31) without requirement for any additional adjustments. The boiler has a fan assisted balanced flue which both discharges the products of combustion to and draws the combustion air from the outside of the room. This boiler is not suitable for outdoor installation. This boiler may be installed in any room, although particular attention is drawn to the installation of a boiler in a room containing a bath or shower where reference must be made to the relevant requirements. Any electrical switch or boiler control utilising mains electricity should be placed so that it cannot be touched by a person using the bath or shower. In GB this is the current I.E.E. WIRING REGULATIONS and BUILDING REGULATIONS. In IE reference should be made to the current edition of I.S.813 "Domestic Gas Installations" and the current ETCI rules. The central heating and domestic hot water (F24E only) temperatures are user adjustable. F24E Only. Domestic hot water demand always has priority over heating demand. The boiler is designed for use as part of a sealed water central heating system with fully pumped circulation. The pump, expansion vessel and associated safety devices are all fitted within the boiler. The boiler can be installed against either an external wall or on an adjacent inside wall, that is, the flue system will pass directly to the rear or to either side to the terminal fitted on the outside wall face. These instructions should be carefully followed for the safe and economical use of your boiler. The 'User Controls and Lighting' section describes how to safely use the boiler. Note: The boiler serial number is marked on the data label attached to the rear of the control box.

Programming 24 Hour or 7 Day Schedules
It may be helpful to write out the programme schedules before beginning. THE CURRENT TIME OF DAY AND DAY OF WEEK MUST BE SET PRIOR TO PROGRAMMING. SEE "SETTING THE TIME" Example Event 1: ON at 7:00AM Monday through Saturday Event 2: OFF at 5:00PM Monday through Friday Event 3: OFF at 7:00PM Saturday Three events need to be entered. Press Prog. key only once. Display shows:
Selecting AM/PM or 24 Hour Time
After pressing reset, the display may show AM (below). The numbered day symbols will be flashing on and off. If the display does not show AM, it is in 24 hour time. To change to AM/PM mode, press and hold the h key and press the 1h key once. AM will appear in display. If display is in AM/PM mode and 24 hour time mode is desired, press and hold the h key, press the 1h key once.

Setting the Time

IF THE h AND m KEYS ARE HELD DOWN LONGER THAN 2 SECONDS, THE NUMBERS WILL ADVANCE RAPIDLY. Press and hold the key during the following:
Event 1 (ON at 7:00AM Monday through Saturday) Press key once. ON symbol appears
Press h key to 07AM Press m key once to 00 Press Day key once is displayed Press Prog. key to enter
(If British Summer Time is in effect, press 1h first) 1. Press h to advance to the current hour (while holding down the key) 2. Press m to advance to the current minute (while holding down the key) 3. Press Day repeatedly to advance to current day key) (while holding down the
Event 2 (OFF at 5:00PM Monday through Friday) Press key twice. OFF symbol appears
Press h key to 05PM Press m key once to 00

Day Key Selections

Press Day Key 0 times 1 time 2 times 3 times 4 times 5 times 6 times 7 times 8 times 9 times 10 times 7 Display Shows Days Every Day Mon.Sat. Mon.Fri. Sat. & Sun. Monday Tuesday Wed. Thursday Friday Saturday Sunday
Press Day key two times 5 is displayed Press Prog. key to enter
Event 3 (OFF at 7:00PM Saturday) Press key twice. OFF symbol appears
Press h key to 07PM Press m key once to 00 Press Day key 9 times until only 6 is displayed Press Prog. key to enter Press key to enter Run Mode
NOTE: If the days are flashing, it indicates the day of the week was not set when setting the time. The timer cannot be programmed unless the day of the week is entered.

Changing an Event

Select the event to be changed with the Prog. key. A new set of days may be selected with the Day key just as in initial programming. Hours and minutes can be changed with the h and m keys. Press Prog. or key to store the new programme.

Deleting an Event

To delete only one or a few events: Press Prog. key until the desired program is displayed. Press m key to :59 and press once more to blank out. Press h key to 11PM and press once more to blank out. key, display will flash for several seconds and then Press enter the Run Mode. Using the reset key will delete ALL events, the time of day, and day of the week.
SOLUTION: The ON or OFF was not entered as part of the program. ON or OFF must be selected.

1 Technical Data F24E

Heating
Heat input (max) NET Q Heat input (min) NET Q 26,94 kW 91,200 BTU/H

F18E SB

Heat input (max) NET Q Heat input (min) NET Q 21,9 kW 74,722 BTU/H
9,91 kW 33,820 BTU/H Heat output (max) NET P 23,6 kW 81,550 BTU/H Heat output (min) NET P 8,9 kW 30,370 BTU/H Efficiency - Sedbuk D 78,3% Maximum heating temperature 87 C Expansion vessel effective capacity 5 litres Expansion vessel charge pressure 0,5 bar Maximum system capacity at 75C 110 litres Safety valve, maximum service pressure 3 bar

Hot water

Heat input (max) NET Q Heat input (min) NET Q Heat output (max) NET P Heat output (min) NET P Maximum hot water temperature Minimum hot water temperature Specific flow rate (for 35C temp rise) Threshold flow rate Maximum supply pressure Minimum supply pressure 26,94 kW 91,200 BTU/H 9,91 kW 33,820 BTU/H 23,6 kW 81,550 BTU/H 8,9 kW 30,370 BTU/H 60 C 38 C 9,8 litres/min. 1,7 litres/min. 10 bar 0,5 bar
11 kW 37,532 BTU/H Heat output (max) GROSS P 19,8 kW 67,556 BTU/H Heat output (min) GROSS P 9,2 kW 31389 BTU/H Efficiency - Sedbuk D 78,8% Maximum heating temperature 87 C Expansion vessel effective capacity 5 litres Expansion vessel charge pressure 0,5 bar Maximum system capacity at 75C 110 litres Safety valve, maximum service pressure 3 bar

Combustion

Products outlet diameter Fresh air inlet diameter Combustion products values 60 mm 100 mm CO (30 ppm) CO2 (5,9%) NOx (76 ppm)

Electrical

Electrical supply Electrical rating Level of protection Fuse rating 230 V ~ 50Hz 122 W fused at 3A IPX4D 1,25mA
Products outlet diameter Fresh air inlet diameter Combustion products values 60 mm 100 mm CO (60 ppm) CO2 (6,7%) NOx (48ppm)

2.3 Gas Supply The gas installation must be in accordance with the relevant standards. In GB this is BS 6891. In IE this is the current edition of I.S.813 "Domestic gas installation". The supply from the governed meter must be of adequate size to provide a steady inlet working pressure of 20mbar (8in wg) at the boiler. Important Notice If your boiler has been converted to use L.P.G. Propane the following note applies: Propane cylinders are under pressure and should never be stored or used indoors residentially. They should only be kept outside. Under no circumstances should L.P.G. Propane cylinders be fitted or stored in basement areas or boiler houses. On completion, test the gas installation for soundness using the pressure drop method and suitable leak detection fluid, purge in accordance with the above standard.

3 Heating System Design

Bypass fully shut

Available pressure (kPa)

Open 1/4 turn Open 1/2 turn Open 1 turn Open 2 turns

(10 kPa = 1 m WG)

Flow rate through heating system (I/h)

Diagram 3.1

The installation of the boiler must comply with the requirements of the current issue of BS6798, in Ireland, refer also to the current edition of I.S.813"Domestic Gas Installations". In GB it is necessary to comply with the Water Supply (Water Fittings) Regulations 1999 (for Scotland, the Water Byelaws 2000, Scotland). To comply with the Water Regulations your attention is drawn to: The Water Regulations guide published by the Water Regulation Advisory Service (WRAS) which gives full details of the requirements. In IE the requirements given in the current edition of I.S.813 "Domestic Gas Installations" and the current Building Regulations must be followed. The F24E and F18E SB are for use with sealed central heating systems. Heating surfaces may consist of radiators, convectors or fan assisted convectors. The safety valve is an integral part of the boiler and it cannot be adjusted. The circulation pump is integral with the boiler. Pipe sectional areas shall be determined in accordance with normal practices, using the output/pressure curve (diagram 3.1). The distribution system shall be calculated in accordance with the output requirements of the actual system, not the maximum output of the boiler. However, provision shall be made to ensure sufficient flow so that the temperature difference between the flow and return pipes be less than or equal to 20C. The minimum flow rate is shown in table 1. 13
The system can be fitted with a lockable control valve if necessary in the main flow or return pipes shown as valve 'A' in diagram 3.2. The piping system shall be routed so as to avoid any air pockets and facilitate permanent venting of the installation. Bleed fittings must be provided at every high point of the system and on all radiators. The total volume of water permitted for the heating system depends, amongst other things, on the static head in the cold condition. The expansion vessel on the boiler is pressurised at 0.5 bar and allows a maximum system volume of 110 litres for an average temperature of 75C and a maximum service pressure of 3 bar. This pressure setting can be modified at commissioning stage if the static head differs. An additional expansion vessel can be fitted to the system if required, see diagram 3.2. Guidance on vessel sizing is also given in a current issue of a BS5449 and BS7074 Part 1, for IE refer to the current edition of I.S.813 "Domestic Gas Installations". Provision shall be made for a drain valve at the lowest point of the system. Where thermostatic radiator valves are fitted, not all radiators must be fitted with this type of valve, and in particular, where a room thermostat is installed. In the case of an existing installation, it is ESSENTIAL that the system is thoroughly flushed prior to installing the new boiler, using a proprietary product from Fernox or Sentinel.

STEP 1.

Outside wall face FLUE LENGTH 90mm

(D) (A)

17mm IMPORTANT "BUTT FIT"

Flue centre line BOILER

STEP 2.
25mm minimum Air Duct over lap

(B) FIXING

COLLAR 25mm SEAL

(G) Drill, screw 2 off

and tape the Air Duct

STEP 3.

(D) ELBOW

(G) (A) (E)

EXTERNAL RUBBER SEALING COLLAR 'O' RING

GASKET

STEP 4.
RESTRICTOR fitted for flue lengths less than 0.5m

(G) 2 off (G) (A) (E)

FIXING (C) COLLAR

STEP 5.

The restrictor must be fitted to the inside of the fan outlet.

Diagram 10.3

Diagram 10.4
10.3 Installation of telescopic flue assembly
10a Horizontal Top Flue Installation
Is suitable for installations that require a max. flue length "L" of 740mm. If a shorter flue length is required, the flue can be cut to a min. length"L" of 260mm rear or 300mm side. See diagram 10a.2 for min. flue lengths. Note: Additional 1 metre extensions, 90 and 45 bends are available. The maximum extended flue is 3.5m. The use of flue bends requires the maximum extended flue lengths to be reduced by 1m. for 90 and 0.5m. for 45.
10a.2 Flue systems rear and side, refer to diagram 10a.1. 10a.3 Flue cutting, refer to diagram 10a.2.
Important: Do not leave any burrs or sharp edges on the cut ends of the pipes.

D A J H I C

The flue kit 86285 comprises: - Air duct pipe... A - Flue duct pipe... B - Elbow... C - Fixing collar seal.. D - Fixing collar.. E - External rubber sealing collar. F - Internal flange.. G - Gasket... H - Screws... I - 'O' rings... J

Horizontal Top flue kit

Diagram 10a.1

Diagram 10a.2

10a.1 The Horizontal Top flue - kit 86285H
Outside wall face L Flue centre line C L 90mm

11643 10092

10a.4 Installation of horizontal top flue assembly
Important: If the flue has been cut, ensure that there are no burrs that could damage the O ring. For flue systems less than 0,5 m long, fit the flue restrictor (a) into the fan outlet, see diagram 10a.4. Remove the backing from the self adhesive gasket (H) and carefully fit gasket to base of elbow (C). Fit both O rings (J) into the flue elbow (C), one at the inlet, one at the outlet. By necessity, they are a loose fit, apply a small amount of suitable lubricant to each O ring when fitting. Fit rubber sealing collar (F), into groove at the outer end of pipe (A). Insert flue duct pipe (B) into inner end of air duct pipe (A), rotate flue duct pipe to locate into groove inside air duct pipe. Fit air/flue duct pipe assembly through the wall with rubber sealing collar to the outside. Fit internal plastic flange (G) onto air duct pipe (A). Fit the fixing collar seal (D) onto the flue duct pipe (B) ensuring it is the correct way round (the larger diameter onto the pipe). Pull air/flue duct pipe assembly inwards to bring rubber sealing collar (F) hard up against external wall. Fit elbow onto boiler and secure with the four screws (I). Carefully push the fixing collar seal onto the elbow ensuring that the flue duct pipe locates into the flue elbow outlet while taking care not to tear the O ring. Fit the fixing collar (E) around the fixing collar seal (D) and secure with 2 screws provided. Push the internal plastic flange (G) along the air duct pipe (A) until engaged against internal wall.

17mm Air duct cutting length L minus 90mm plus 17mm = cutting length Flue duct Air duct
Flue duct cutting length Air duct cutting length + 95mm = cutting length
25mm check dimension (cut end)

Diagram 10a.3

Horizontal Top flue system
The maximum permissible length (L) is 3.5 m. For flue systems up to 0.5 m length, the flue restrictor must be fitted (a) inside the fan outlet. For longer flue systems, the restrictor must not be fitted. For each 90 flue elbow used, (or two 45 elbows) the maximum permissible length (L) must be reduced by 1 metre.

FLUE RESTRICTOR

Gasket

Diagram 10a.4

11 Electrical Connection
WARNING: This appliance must be earthed. This appliance must be wired in accordance with these instructions. Any fault arising from incorrect wiring cannot be put right under the terms of the Saunier Duval guarantee. All system components must be of an approved type. Electrical components have been tested to meet the equivalent requirements of the BEAB. Do not interrupt the mains supply with a time switch or programmer. Connection of the whole electrical system and any heating system controls to the electrical supply must be through a common isolator. Isolation should preferably be by a double pole switched fused spur box having a minimum contact separation of 3mm on each pole. The fused spur box should be readily accessible and preferably adjacent to the boiler. It should be identified as to its use. A fused three pin plug and shuttered socket outlet may be used instead of a fused spur box provided that: a) They are not used in a room containing a fixed bath or shower. b) Both the plug and socket comply with the current issue of BS1363.

11.1 Mains Cable

Important: If a replacement supply cable is required it must be purchased. Part No. S1008600.
11.2 Voltage Free External Controls
WARNING: UNDER NO CIRCUMSTANCES MUST ANY MAINS VOLTAGE BE APPLIED TO ANY OF THE TERMINALS ON THE VOLTAGE FREE HEATING CONTROLS CONNECTION TERMINAL. This boiler will operate continuously on heating, as supplied, if the wire link (E), fitted between the two terminals of the heating controls connection, is left in place, see diagram 11.1. External heating controls e.g. Room thermostat, should be fitted in accordance with the rules in force and as shown in the example, diagram 11.2.

RETAINING SLOTS

CONTROLS PANEL REAR COVER SECURING SCREW (3)

MANOMETER

P. max.

POTENTIOMETER P3

POTENTIOMETER P6

SW1 DIP SWITCH

Factory set in "OFF" position
USER INTERFACE BOARD Diagram 12.2

Dip Switches

The position of the SW1Dip Switch(s), see diagram 12.2, and the table below can be used to change the operation of the PUMP OPERATION WITH BURNER WITH HEATING DEMAND FACTORY SETTING
pump and maximum heating temperature of your boiler.

DIP SWITCH 1 ON OFF*

* GB/IE PREFFERED SETTING 28

Ins 062a

7. Ensure the display indicates a system pressure of 1.0 bar adjust if necessary.
8. Open various hot water taps to bleed system
Leave cap open on automatic air vent.
When all adjustments are completed. Adjust heating temperature to maximum. Check that any external controls, if fitted, are calling for heat (set room thermostat to maximum). Allow the temperature to rise to the maximum value, with all radiator valves open. The temperature rise will cause release of the air contained in the water of the central heating system. Air driven towards the boiler will be automatically released through the automatic air vent. The air trapped at the highest point of the system must be released by bleeding the radiators. Check the burner gas rate required, ten minutes after lighting. Refer to Data Label on electrical controls box. Should there be any doubt about the gas rate it should be checked at the meter, refer to technical data. On reaching maximum temperature, the boiler should be turned off and the system drained as rapidly as possible whilst still hot. Refill system to a pressure of between 1 and 2 bar and vent as before. Restart boiler and operate until a maximum temperature is reached. If necessary, refer to section 14 to adjust the bypass. Shut down boiler and vent heating system. If necessary, top up heating system and make sure that a pressure of at least 1 bar is indicated when system is COLD. F24E Only Flush the domestic hot water system by opening the hot water taps for several minutes. Please ensure the Benchmark logbook is completed and left with the user and the magnetic lighting instruction label is placed on the surface of the boiler casing.

Instruct the User

Instruct and demonstrate the lighting procedure and advise the user on the safe and efficient operation of the boiler. Instruct on and demonstrate the operation of any heating system controls. Advise the user on the use and maintenance of any scale reducer and pass on any relevant instructional documents. Advise that to ensure the continued efficient and safe operation of the boiler it is recommended that it is checked and serviced at regular intervals. The frequency of servicing will depend upon the installation conditions and usage, but in general, once a year should be enough. Draw attention, if applicable, to the current issue of the Gas Safety (Installation and Use) Regulations, Section 35, which imposes a duty of care on all persons who let out any property containing a gas appliance in the UK. It is the Law that any servicing is carried out by a competent person. Advise the user of the precautions necessary to prevent damage to the system, boiler and the building, in the event of the heating system being out of use during frost or freezing conditions. Advise the user that the permanent mains electrical supply SHOULD NOT be switched off, as the built in frost protection and pump saver program would not be operable. Reminder, leave these instructions and the Benchmark logbook with the user.

PRODUCTS SAMPLING POINT Diagram 15.1
15.1 Products of combustion check
Note: To obtain a products of combustion reading, unscrew the left hand sampling point cap on the flue elbow, located on top of boiler, see diagram 15.1. Connect the analyser tube onto sampling point. Refer to the combustion product values in Section 1 Technical Data. Switch on the electrical supply and gas supply, then operate the boiler. On completion of the test switch off the electrical supply and the gas supply, remove analyser tube and replace sampling point cap.
15.2 Service Check and Preparation.
Isolate boiler from the gas and electrical supplies. (F24E Only) Drain the Domestic hot water circuit, refer to diagram 15.2. Drain the boiler, refer to diagram 15.2. On completion check all gas-carrying parts for soundness with leak detection fluid.
To Drain the Domestic hot water circuit (F24E Only)
Close boiler isolating valve (b). Turn on one or more hot water taps.

To Drain the boiler

Close isolating valves (a) and (c). Open the boiler drain valve (f).
COLD WATER INLET (F24E Only)

(c) (f)

BOILER DRAIN VALVE HEATING FLOW
DOMESTIC HOT WATER OUTLET (F24E Only)
GAS SERVICE COCK Diagram 15.2
Note: Isolating cocks water and gas are shown in the: OFF position

15.3 Front panel

Unscrew and remove the two retaining screws from the bottom of the front panel. Remove front panel by lifting up and forward.

15.4 Control panel

Lower forwards to gain access to lower part of boiler.
15.5 Sealed chamber cover
Unscrew and remove the two retaining screws from the sealed chamber cover, see diagram. 15.3. Lift cover up and off pins on top of boiler.
15.6 Side panels (for ease of access if available), refer to diagram 15.4
Unscrew and remove the two retaining screws from front of each side panel. Left hand side panel only disconnect the control panel retaining strap at the control panel. Unhook each panel from the front retaining tabs. Pull each panel forward from the rear retaining tabs to remove.
15.7 Combustion chamber cover
Unscrew and remove the two screws securing combustion chamber cover to combustion chamber, see diagram 15.5. Remove combustion chamber cover from boiler.

Diagram 15.3

15.8 Ignition and Flame Sensing Gaps
Check that the ignition and flame sensing gaps as shown in diagram 15.6. Note: To gain access to ignition and sense electrodes for removal, refer to Section, 18.11 and 18.12 in Replacement of Parts.

All parts are replaced in reverse order to removal.

RETAINING CLIP

Diagram 15.11
15.12 (F24E Only) Domestic water inlet filter, refer to diagram 15.10

16 Fault Finding

Before trying to operate the boiler make sure that : All gas supply cocks are open and that the gas supply has been purged of air. The heating system pressure is at least 1 bar. There is a permanent mains supply to the boiler and that the polarity is correct. WARNING. Always isolate the boiler from the electrical supply before carrying out any electrical replacement work. Always check for gas soundness after any service work. Should there be any doubt about the voltage supply to any of the components, it is possible to carry out a simple electrical test to ensure all is operational in that area. IMPORTANT: On completion of the fault finding task which has required the breaking or remaking of the electrical connections, the continuity, polarity, short circuit and resistance to earth checks must be repeated using a suitable multimeter.
Overheat thermostat reset button
Refer to Section 18.10 to locate the overheat thermostat reset button. Depress the button to reset.

OVERHEAT THERMOSTAT

RESET BUTTON

Diagram 16.1

TYPE OF FAULT No display on control panel CHECK 230V supply PCB fuse Connection between PCBs Loose connections on control board (PCB) Connections on air pressure switch (electrical or tubes) disconnected Faulty control or interface board (PCB's) Water pressure, flashing pressure Shortage of air or gas Faulty temperature sensor Overheating
No domestic hot water F24E Only) No central heating (Red flashing warning light and flashing fault code in display)

COMPONENT TESTING DATA

COMPONENT Gas control valve Resistance of coil 116 NORMAL MEASURE Under demand during ignition sparks: 24V dc for 1 to 2 seconds, then 12Vdc (constant) at the gas control valve electrical connection. CHECK If 0 Volt: the gas control valve is not faulty. If 24 Volts and then 12 Volts but no gas at the burner: Check if the gas control valve is stuck. If not, check the adjustment valve. If the valve does not move: Check the connections at both motor and control board (PCB). Change the motor. Replace the control board (PCB).

YES Is the boiler actually designed for the gas being used. NO Change the gas type for the boiler (gas conversion kit).
YES Clean the gas filter. Clean the burner.
F1 or F4 FAULT DISPLAYED FAULT: THE BURNER LIGHTS, THEN GOES OUT. The flame is spreading across the whole burner, but not being detected. CHECK THE CHECK PROBE THE MAINS With the power turned off, check the continuity between the flame sense electrode and terminal H2. 4 on the control board (PCB). Check the connector on the end of the wire. Check that the spark electrode is pointing towards the flame. Check the spark electrode. Change it.
FAULT NOT FOUND If the problem persists, change the control board (PCB). (flame detection module faulty).
F1 FAULT DISPLAYED FAULT: THE BURNER DOES NOT LIGHT AT ALL, BUT THERE IS AN IGNITION SPARK. Are the gas taps on? YES Is there 24Vdc at the gas control valve? for testing see component testing data. YES Test the gas control valve. Check resistance of safety valve coil. NO Check the wiring. If the problem persists, change the control board (PCB). NO Turn on the gas taps.
FAULT: THE ROOM TEMPERATURE IS INADEQUATE AND RADIATORS ARE LUKE-WARM. Is the room thermostat and or radiator set high enough and calling for duty? NO Turn up settings YES Is the heating temperature on the boiler set high enough? YES Is the heating power adequate? - Check set point P3. (Refer to Commissioning) - Check dip switch setting. (Refer to Commissioning) - Check the adjustment of the by-pass internal and external (If fitted). - F24E Only Check the 3-way valve is not passing into the domestic hot water heat exchanger.
16 Fault Finding F24E ONLY
FAULT: THE WATER AT THE TAPS IS LUKE-WARM. Is the temperature higher if you reduce the flow through the taps? NO Check the 3-way valve is not passing into the radiators. (The radiators should stay cold in Summer setting)
YES Check that the cold water inlet restrictor is fitted. Check the rate of flow. Check burner pressure is correct.
FAULT: THE FAN DOES NOT START. Is there is 230V ac at fan during demand? YES Faulty fan, replace. NO
Check continuity of fan harness. YES

Faulty PCB, replace.

FAULT: THE FAN RUNS BUT THERE ARE NO SPARKS. CHECK CONTINUITY OF IGNITION (ELECTRODES AND LEADS) CHECK POWER SUPPLY FROM PCB TO IGNITION UNIT CONNECTIONS TO THE AIR PRESSURE SWITCH Pr
Air flow switch take-off.

Electrical contacts.

17 Wiring Diagram F24E
FAN g/y br b w OVERHEAT THERMOSTAT or w THERMISTOR CH WATER PRESSURE SENSOR b b w g THREE-WAY VALVE bk bk w p y g or gn CHASSIS EARTH w GAS CONTROL VALVE PUMP g/y AIR PRESSURE SWITCH bk IGNITION PLUG ELECTRODES IGNITOR UNIT

SENSE ELECTRODE

MAINS VOLTAGE HEATING CONTROLS PLUG

PUMP ELECTRICAL CONNECTION BOX
18.17 Mains switch, refer to diagram 18.10.
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Unclip control panel user interface and hinge forward. Do not strain the cables. Disconnect the electrical connections from mains switch. Remove the mains switch.

Diagram 18.11

Unclip control panel user interface and hinge forward. Do not strain the cables. Disconnect the electrical connection from the programmer. Undo the two securing screws and remove the programmer.
18.18 230V Controls board, refer to diagram 18.10.
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Unclip control panel user interface and hinge forward. Do not strain the cables. Disconnect the electrical connection from the 230V controls board and the electrical connection from printed circuit board (PCB). Remove the 230V controls board retaining screw. Remove the 230V controls board.
18.20 Central heating pump head, refer to diagram 18.11.
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Lower the control panel, refer to Section 15.4. Drain down central heating water circuit of the boiler only, refer to relevant part of diagram 18.1. Note: it is not necessary to drain down the entire heating system to carry out this work. For ease of access if required remove the right hand side panel, refer to Section 15.6. Undo four head fixing screws and remove pump head. Gain access to the pump electrical connection box and remove cover. Disconnect pump cable from pump (avoid straining cables). Connect electrical connection to replacement pump head. Fit replacement pump head.
18.19 (F24E Only) Analogue programmer, refer to diagram 18.10
18.21 (F24E Only) Filling system tap, refer to diagram 18.12.
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Lower the control panel, refer to Section 15.4. Drain down the hotwater circuit, refer to relevant part of diagram 18.1. Pull of the filling loop tap extension. Pull out slotted metal clip securing tap into housing, remove tap. Pull out slotted metal clip and remove pipe from tap.
18.22 (F24E Only) Reduced pressure zone valve (RPZ), refer to diagram 18.12.
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Lower the control panel, refer to Section 15.4. Drain down the boiler only, refer to relevant part of diagram 18.1. Pull out slotted metal clip securing pipe to RPZ. Pull out slotted metal clip securing RPZ into housing, remove RPZ.
WATER FLOW SENSOR Diagram 18.14 BYPASS VALVE
SYSTEM WATER PRESSURE SENSOR
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Lower the control panel, refer to Section 15.4. Drain down the boiler only, refer to relevant part of diagram 18.1. Pull out slotted metal clip securing boiler drain valve into housing, remove boiler drain valve.

Diagram 18.18

PRESSURE RELIEF VALVE
Note: Use the new washers supplied with the gas control valve. Fit gas valve restrictor to replacement gas control value. Fit replacement gas control valve. Check the Min. gas pressure and if it requires adjusting, refer to Section 13 Changing Gas Type.

Diagram 18.19

9768 9769
18.29 Gas control valve stepper motor, refer to diagram 18.18
Remove the front panel, refer to Section 15.3. Lower the control panel, refer to Section 15.4. Remove the gas control valve, refer to Section 18.28. Disconnect the electrical connection from stepper motor. Remove the two screws securing stepper motor to the gas control valve. Fit replacement gas control valve stepper motor. Note: Take care not to damage the 'O' ring.
18.30 Discharge safety valve, refer to diagram 18.19.
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Lower the control panel, refer to Section 15.4. Undo discharge pipe union nut. Pull out slotted metal clip from valve body and remove valve.
18.31 (F24E Only) Three-way valve head, refer to diagram 18.20.
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Lower the control panel, refer to Section 15.4. Remove gas control valve, refer to Section 18.28. (It will not be necessary to remove the gas control electrical cables). Remove electrical plug from valve head. Pull out slotted metal clip from valve body and remove valve head from body. Fit replacement valve head. Note : 1) When refitting clip, ensure that letters YES are as shown. 2) It is not necessary to drain boiler to carry out this work.

THREE WAY VALVE ACTUATOR

Diagram 18.21

IGNITION UNIT

Diagram 18.22
THREE WAY VALVE HEAD Diagram 18.20 THREE WAY VALVE/ BYPASS HOUSING
Before starting refer to the front of Section 18 Important information.

Disconnect the pressure relief valve discharge pipe. Disconnect the mains cable and any external controls cables. Lift up to remove the boiler from the wall. Remove sealed chamber cover, refer to Section 15.4. Remove the right hand side panel, refer to Section 15.6. From the rear of the boiler, unclip wiring harness retaining wire. Undo pipe coupling on expansion vessel. Unscrew and remove expansion vessel bracket retaining screw.
Note: Check that expansion vessel pressure is correct, see Section 1 Technical Data.
18.36 Sealed chamber cover seal, refer to diagram 18.25
Before starting refer to the front of Section 18 Important information. Remove the front panel, refer to Section 15.3. Remove the sealed chamber cover, refer to Section 15.5. Remove the old seal, thoroughly clean the casing. Fit the new seal, it is supplied to the correct length. Note: Ensure the seal is fitted correctly giving an air tight seal.
SEAL SEALED CHAMBER COVER Diagram 18.25
Slide expansion vessel to the left and forward to remove.

FRONT PANEL

Disconnect the fixing jig connection pipes at the boiler.
For this operation the boiler must be removed from the wall.

18.35 Expansion vessel

19 Spare parts
When ordering spare parts, quote the part number and description, stating the appliance model number and serial number from the data badge.
Short parts list No. Description Central heating thermistor Fan Air pressure switch F24E only Domestic water flow sensor Printed circuit board - Main Pump head System water pressure sensor Gas control valve (G20) Gas control valve (G30) Discharge safety valve Overheat thermostat Ignition electrode Flame sense electrode 230V controls board User interface PCB Stepper motor (G20) Stepper motor (G30) Ignition unit F24E only Three way valve head Three way valve actuator Heat exchanger Burner Part No. S57398 S10088 S10089 S57202 S10082 S10052 S57205 S10045 S10046 S10067 S10080 S10038 S10037 S10091 S10081 S57434 S57435 S57427 S57206 S10064 S10030 S10042 G.C. No.
Because of our constant endeavour for improvement details may vary slightly from those in the instructions.