The Vokra Linea 24 & 28 are combined central heating and domestic hot water appliances. By design they incorporate full sequence electronic ignition, circulating pump, expansion vessel, safety valve, temperature gauge, pressure gauge and 3 port diverter valve. They are produced as room sealed appliances suitable for wall mounting applications only. They are provided with a fan powered flue outlet with an annular co-axial combustion air intake which can be rotated through 360 degrees. A vertical & twin flue option is available They are also suitable for S.E. duct installation.
Fig.1 General Layout Flue Outlet Air Intake & Restrictor Ring Pressure Differential Switch Silicone Pressure Tubes Expansion Vessel Main Heat Exchanger Flow NTC Electrode Gas Valve & Ignition Control Modulator Coil Domestic Heat Exchanger Domestic Hot Water Flow Switch Status LED Temperature Indicator Central Heating Temperature Control Combustion Switch Timeclock Aperture (optional) Pressure Gauge Mode Selector Switch Hot Water Temperature Control Safety Valve Pressure switch Diverter Valve Motor Pump Automatic Air Release Valve Main Burner Combustion Chamber Fan Assembly Air Chamber (with front removed) Flue Gas Analysis Test Point

SECTION 2

DESIGN PRINCIPLES AND OPERATING SEQUENCE
2.3 2.3.1 Domestic Hot Water Mode The appliances incorporate a hot water preheat facility. The appliance will therefore ignite periodically to maintain heat within the appliance. The appliance will operate in domestic hot water mode whenever the mode selector switch is on regardless of mode selector switch position and any demand for central heating. The diverter valve will automatically energise into the hot water position after central heating demand, or will stay in the hot water position after hot water demand. Opening a draw off tap will energise the pump and fan sending primary water to the domestic hot water heat exchanger. Temperature control is transferred to the domestic hot water thermostat (potentiometer) which modulates the burner output between high and low flame to maintain an average heat input to suit the dhw output required. An overrun is incorporated in the boiler in both c/h & dhw modes. The fan overruns until the boiler water cools to approximately 80C (176F). Safety Devices In both central heating and hot water modes safe operating is ensured by: A. Differential pressure unit in the primary circuit which prevents burner operation if water pressure is too low. B. An electronic device that checks the primary pressure unit for activation. Failure results in deactivation of the pump, after approximately 10 minutes of operation. C. A safety thermostat, which interrupts the control circuit shutting off the gas valve. At the same time the fan will still operate. D. A Pressure differential switch in the flue system to check the fan's operation before allowing ignition. 2.4.11 2.4.3 A safety valve is provided to relieve excess pressure from the primary circuit. Frost Thermostat The appliance has a built in frost protection circuit. Should the boiler temperature sensed at the primary thermistor fall below 5C, the boiler will operate in central heating mode and continue to operate until the primary thermistor reaches approximately 40C.

Pipework from the meter to the boiler must be of adequate size. Pipes of a smaller size than the boiler inlet connection should not be used. The complete installation must be tested for soundness as described in the above code. N.B. If the gas supply for the boiler serves other appliances ensure that an adequate supply is available both to the boiler and the other appliance when they are in use at the same time. Flue System The terminal should be located where dispersal of combustion products is not impeded and with due regard for the damage or discoloration that might occur to building products in the vicinity (see fig 4). The terminal must not be located in a place where it is likely to cause a nuisance. In cold and/or humid weather water vapour may condense on leaving the flue terminal. The effect of such steaming must be considered.
For protection of combustibles, refer to BS 5440:1 where the terminal is less than 2m (6.6ft) above a pavement or platform to which people have access (including any balcony or flat roof the terminal must be protected by a guard of durable material). A suitable guard is available from Vokera Ltd. Part No 018, G.C. No. This guard must be fitted centrally over the terminal. Mark the positions of the fixings, drill the wall and secure using wall plugs and 3 of 1" No.8 plated screws. Fig. 4
Water Circulation (Central Heating) Detailed recommendations are given in BS 6798:1987 and BS 5449:1:1990 (for smallbore and microbore central heating systems). The following notes are given for general guidance. Pipework Copper tubing to BS 2871:1:1971 is recommended for water pipe. Jointing should be either by capillary soldered or with compression fittings. Where possible, pipes should have a gradient to ensure air is carried naturally to air release points and water flows naturally to drain taps. It should be ensured as far as possible that the appliance heat exchanger is not a natural collecting point for air. Except where providing useful heat, pipes should be insulated to prevent heat loss and to avoid freezing. Particular attention should be paid to pipes passing through ventilated spaces in roofs and under floors.

4.6.1 4.6.2

Terminal position for fan assisted boiler (minimum distance) mm A - Directly below an open window or other 300 opening (e.g. air brick) B - Below gutters, soil pipes or drain pipes 25 C - Below eaves 25 D - Below balconies or car port roof 25 E - From vertical drain pipes and soil pipes 75 F - From internal or external corners 25 G - Above ground or below balcony level 300 H - From a surface facing a terminal 600 I - From a terminal facing a terminal 1200 J - From an opening in the car port (e.g. door window) into dwelling. 1200 K - Vertically from a terminal on the same wall 1500 L - Horizontally from a terminal on the same wall 300 M - Horizontally from a vertical terminal to a wall 300 N Horizontally from an opening, airbrick, openable window, etc. 300

By-Pass An automatic by-pass is incorporated in the boiler, but systems should be designed to ensure that with all radiators turned off a flow rate of at least 350 litres/hour (1.28 gals/min) is achieved through the system. See 6.9.4 System Design Figs 5 & 5a illustrates typical system layouts showing options of either, pipe connection from below as fig. 5, or pipe connection from above utilising the purpose made duct in the rear frame of the appliance. Draining Taps These must be located in accessible positions to permit the draining of the whole system. The taps must be at least 15mm nominal size and manufactured in accordance with BS 2879:1980.
NOTE: The flue must be terminated in a place not likely to cause a nuisance. 4.5 Air Supply The following notes are intended for general guidance. The room sealed fan flued boiler does not require a permanent air vent for combustion air supply. Where installed in a cupboard or compartment ventilation is not required.

Fig. 5

Fig. 5a
Vokra Ltd recommend a 2-pipe system. Single pipe systems are more liable to be troublesome unless carefullly designed and installed. 7
Air Release Points These must be fitted at all high points where air will naturally collect, and must be sited to facilitate complete filling of the system. The appliance has an integral sealed expansion vessel to accommodate the increase of water volume when the system is heated. It can accept up to 8 litres (1.8gals) of expansion water. If the appliance is connected to a system with an unusually high water content. Calculate the total expansion and add additional sealed expansion capacity as appropriate. In general, modern systems will present no problem.

Fig. 6

Filling Loop Cold water Inlet Stopcock/ filling valve C/H Flow Valve
Filling Point A method for filling the system and replacing water lost during servicing is provided on the appliance. This method complies with the Water Supply (Water Fittings) Regulations 1999.
Electrical Supply The appliance is supplied for operation on 230V ~ 50Hz electricity supply. It should be protected with a 3-amp fuse. THIS APPLIANCE MUST BE EARTHED. The method of connection to the mains electricity must allow complete isolation from the supply. The preferred method is by using a fused double pole switch with a contact separation of at least 3mm. The switch must supply ONLY the appliance and immediate electrical control circuits (e.g. programmer / room thermostat) Alternatively, use an unswitched shuttered socket outlet with a fused 3-pin plug both complying with BS 1363.

Gas Cock C/H return valve Safety valve outlet

Hot water Outlet

Fig. 7
Showers If a shower control is to be supplied from the combination unit it should be of the type which incorporates a thermostatic control and by design is suitable for use with a combination boiler. Check application with shower manufacturer. Timber framed buildings If the appliance is to be fitted in a timber framed building, it should be fitted in accordance with the Institute of Gas Engineers publication (IGE/UP/7) Guide for Gas Installations in Timber Frame Buildings.

SECTION 5

Fig. 8

INSTALLATION

5.1 Delivery (fig. 8) The appliance is delivered in a heavy duty cardboard carton. Lay the carton on the floor with the writing the correct way up. 5.2 Unpacking (fig. 9) Pull both sides of the top of the carton open. Do not use a knife. Remove the hanging bracket, literature pack and fittings pack, from the packaging. Remove the package supports. Lift the appliance from the carton and lay the appliance down with the white frame on the floor. Remove the protective bag, and the polystyrene support from the back of the appliance. Do not remove the insulation jacket on the domestic heat exchanger.

Fig. 9

The fittings pack contains Wiring harness for optional built in timer 15mm nut & olive Adjustable stopcock Safety valve outlet pipe (1) Filling loop hose (1) Various washers Flue kit supplied in separate carton. 5.3 5.3.1 Preparing for Mounting Push to release front door panel and lower to reveal controls. Loosen the 2 captive screws securing the front control panel to the lower part of the casing and lower to reveal inside of boiler. (fig. 10) Remove two screws at base of casing, slightly lift the casing and slide it gently towards the top of the appliance to disengage the case from the top suspension hooks. (Fig. 11) Ensure the casing and screws are put to one

Fig. 10

Fig. 11

Case Screws

Case screws (one either side)

TWIN FLUE SYSTEM The Vokera twin flue system enables greater flue distances to be achieved (see 5.4.2) than that of the standard concentric flue system. It can be used for horizontal or vertical applications, however the twin flue system must be converted to the dedicated concentric flue kit for termination. It is essential that the installation of the twin flue system be carried out in strict accordance with these instructions. GUIDANCE NOTES ON TWIN FLUE INSTALLATION The flue must have a fall back of 1 back to the appliance to allow any condensate that may form in the flue system to drain via the condensate drain. Consideration must also be given to the fact that there is the possibility of a small amount of condensate dripping from the terminal. Ensure that the entire flue system is adequately supported, use at least one bracket for each extension. The entire flue system must be adequately insulated to maintain heat within the flue system thereby reducing the possibility of condensate production. As the exhaust outlet pipe can reach very high temperatures it must be protected to prevent persons touching the hot surface.

Reduction for bend

Bend 45 bend 90 bend Reduction in maximum flue length for each bend 1.0 metre 1.0 metre

Twin flue accessories

Part No. Description Horizontal flue terminal Vertical flue terminal Twin adapter kit Pitched roof flashing plate Flat roof flashing plate Condensate drain kit 0.25m extension (pair) 0.5m extension (pair) 1.0m extension (pair) 2.0m extension (pair) 45 bend (pair) 90 bend (pair) Twin bracket (5) Single bracket (5) Length 1.0 metre 1.0 metre N/A N/A N/A N/A 250mm 500mm 1000mm 2000mm N/A N/A N/A N/A

Fig. 14

Mounting the boiler The fixing holes for the wall-mounting bracket & jig should now be drilled and plugged, an appropriate type and quantity of fixing should be used to ensure that the bracket is mounted securely. Once the bracket has been secured to the wall, mount the appliance onto the bracket & jig. 5.5.3.1 Installation of twin adaptor kit (fig. 15)
1 metre of the appliance flue outlet. It is recommended that the condensate drain kit should be fitted in the vertical plane, however it can be fitted horizontally with care. Fit the first bend to the condensate drain kit or exhaust connection manifold by firmly pushing in to position. Using the two holes in the exhaust connection manifold as a guide, drill a 3mm hole in each and secure using the screws provided. Connect the air inlet pipe to the air baffle as above. The twin flue pipes extensions and accessories can now be installed by pushing together (the plain end of each extension or bend should be pushed approximately 50mm into the female socket of the previous piece). The condensate drain trap must be connected to the drain in accordance with Building Regulations or other rules in force 5.5.3.3 Horizontal termination ( fig. 17) The twin flue system must be converted to the dedicated concentric flue kit for termination. The horizontal terminal is supplied with a built-in converter box and cannot be shortened.

Cold Water Connect a 15mm cold water service pipe to the inlet stopcock of the appliance. Tighten the nut. If the cold water supply is liable to high pressure or large pressure fluctuations, a flow/ pressure regulator should be fitted in the supply pipe. Should the appliance be subject to 'mains knock' it would be advisable to install a non return valve in the hot water outlet pipe to prevent unnecessary activation of the domestic flow switch. Fig. 19

Earth Screw

Factory Fitted Link Between = & TA
Safety Valve Discharge Connect a 15mm pipe to the discharge outlet of the appliance. The discharge should terminate facing downwards outside the building in a position where discharging (possibly boiling) water will not create danger or nuisance; but in an easily visible position.

5.7 5.7.1

Electrical Connections The electricity supply must be as specified in 4.7. If controls external to the appliance are required, design of the external electrical circuits should be undertaken by a competent person. See Section 10 for further advice. Fig. 19a
Mains Input and External Controls Terminal Block
Pass the cable through one of the cord anchorage points and connect the wires Brown to L, Blue to N, and Green/Yellow to. Arrange the cable so that should the cable slip the anchorage the current carrying conductors become taut before the earthing conductor. Securely tighten all terminal screws and arrange the cable with slack between the cable anchor and the terminal block. Tighten the cord anchorage screw until the cable is secure. Neatly arrange the external cable in such a way that unrestricted opening of the controls fascia is possible without strain on the cable. External controls may be wired from terminals TA to TA after removing the factory fitted link (see fig. 19 & pages 49-52 for further details). If a neutral is needed use the terminal marked N on the terminal strip. DO NOT CONNECT ANY WIRES TO THE TERMINAL STRIP MARKED 'S' '-' 'POS' 'POS' When connecting wires to the terminal strip it is possible to remove the terminal strip from the circuit board: Grasp the terminal strip firmly and slide up to clear pcb. See fig.22. When refitting the terminal strip it is important that it is replaced correctly (with the screws facing left). Section 10 gives details of fitment for external and internal controls (ie Vokra time clock). If required pass the external controls cable through the spare cord anchorage and arrange the cable so that should the cable slip the anchorage the current carrying conductors become taut before the earthing conductor.

6.6.2 6.6.3

If the grey wire from the modulator coil was removed to check the minimum setting, turn off the electricity supply and replace the wire onto the modulator coil.

Gas Valve

U Gauge Tube

Fig.23

Manometer
Setting the Maximum Rate for Central Heating The maximum heat input for the central heating mode is not adjustable. When central heating is selected the appliance will light at 75% of maximum heat input for a period of approximately 15 minutes, whereupon the appliance will burn at maximum rate. Should the appliance reach temperature during the 15 minute period the burner will modulate further to suit system load.

6.11 6.11.1

Filling, Testing and Regulating the Domestic Hot Water System Start with the appliance switched on having completed the procedures described in 6.4 to 6.10. Open a domestic hot water tap (Preferably the bath tap). Ensure cold water inlet stopcock is fully open (vertically up) and the dhw control knob (21) is set at maximum.

6.11.2

6.7 6.7.1
Checking the Flue System The flue system should be visually checked for soundness. Check all clamps and fixings are secure and tight. Checking the Heating Thermistor Allow the system to warm up and manipulate the c/h control knob to ensure that the burner modulates between high and low and then to off and vice versa (scale range covers approx. 45 - 85C). Regulating the Central Heating System Fully open all radiator and circuit valves and run the appliance in the central heating mode until heated water is circulating. If conditions are warm, remove any thermostatic valve heads. If the burner will not light, ensure that water is in fact circulating. See 4.6.3 Adjust radiator return valves and any branch circuit return valves until the individual return temperatures are correct and are approximately equal. When all is adjusted, progressively close all radiator valves to ensure that the appliance still operates when flow through the system is limited. The system should be regulated to ensure a flow rate of at least 350 litres/h (78 gals/h). This may mean the addition of a small manual by-pass being fitted to the system if a fully TRV system is used.

6.11.3

Set the adjustable stopcock to restrict the maximum flow of water and achieve a temperature rise acceptable to the end user. The flow of water should activate the domestic hot water flow switch (13) and drive the diverting valve (23) to its hot water position thus heating the domestic water flowing through the dhw heat exchanger. At the same time the pump and fan are activated lighting the burner on maximum rate. If the burner does not light, check that the water flow rate is above the minimum required to operate the domestic hot water flow switch (13) 2.0 litres/min (0.45 gals/min). The temperature of the water will depend on the rate at which it flows. The temperature of water at the tap can be varied by adjusting the water flow rate at the tap up to the maximum predetermined quantity.The hot water temperature control knob (21) will govern the maximum temperature. When the appliance is being used in hot water mode the temperature indicator (15) indicates the temperature of the hot water leaving the appliance.

8.8.1 8.8.2 8.8.3 8.8.4 8.8.5
Gain general access as 8.4 Remove room sealed front cover plate (8.5). Remove front of combustion chamber (8.6.3). Remove two air baffle plates, 1 screw securing each (fig. 31). Remove electrical plug from primary thermistor Remove both side panels, 2 screws each (fig. 29) Fig. 29 a
Close heating flow and return valves by turning 1/4 turn until indicating lines are horizontal. Pull lever on head of safety valve to drain primary circuit to boiler. Place cloth under heat exchanger to catch surplus water.

Fig. 30

8.9 8.9.1 8.9.2 8.9.3 8.9.4
Flue Fan Part No. 24-5910 28-5911 Remove room sealed front cover plate (8.5) and front of combustion chamber (8.6.3). Loosen maintenance clip securing screws (see fig. 31) and slide upwards to clear joint. Remove silicone pipes from nozzles on inner flue bend Remove 5 flue hood retaining screws (see fig. 31). NOTE: When removing the two side screws the two air baffle plates can be removed.

8.9.5 8.9.6

Carefully slide flue hood forward disconnecting electrical leads on fan in the process. Unscrew 4 screws securing fan to flue hood and remove fan. Transfer aluminium manifold (two screws) to new fan. Reassemble in reverse order, replacing centre hood screw first. Flue Pressure Differential Switch Part No 24&28-9232 Refer to Fig. 31 Gain general access as 8.4 Remove room sealed cover (8.5) Remove 2 screws holding pressure differential switch to the combustion chamber. Pull off tab connectors and remove pressure switch, disconnecting the air pressure pipes in the process. Reassemble in reverse order. See fig. 41&43 for correct fitting of electrical connections. When reconnecting the pressure pipes the upper nozzle on the inner flue bend connects to: The front nozzle of the pressure differential switch. Maintenance clip Pressure differential switch

8.9.7 8.10

8.10.1 8.10.2 8.10.3 8.10.4

8.10.5

Air baffle plate

Air tubes

8.11 8.11.1 8.11.2
Combustion Chamber Insulation Boards Gain general access as 8.4 Remove room sealed front cover 8.5 Remove front of combustion chamber 8.6.3. Remove Main Heat Exchanger 8.8. To remove side combustion chamber insulation boards, gently prise upwards and pull out. To remove rear board, gently prise upwards and pull out. Fourth panel (front) is replaced complete with combustion chamber front panel. Hood Retaining Screws Fig. 31

8.11.3 8.11.4 8.11.5

8.12 8.12.1 8.12.2 8.12.3 8.12.4 8.12.5
Ignition PCB Gain general access as 8.4. Remove PCB cover. Disconnect wires from ignition PCB. Remove ignition PCB. Replace in the reverse order ensuring wires are replaced correctly.
8.13 8.13.1 8.13.2 8.13.3 8.13.4 8.13.5 8.13.6 8.13.7 8.13.8 8.13.9
Gas Control Valve (complete) Part No. 24&28- 1836 fig. 32 Turn off gas service tap. Remove Ignition control box as 8.12 Pull off silicone tube from gas valve regulator. Disconnect earth leads from gas valve. Disconnect wires from modulator coil. Unscrew gas service tap union & release from its seating. Remove 2 screws securing gas valve bracket to the base frame. Undo union above the gas control valve & withdraw gas valve. Reassemble in reverse order.

8.13.10 Test all joints for gas soundness. 8.13.11 Check burner pressures. As detailed in 6.6 If incorrect adjust as instructed in 8.23.
Silicon Pipe Connection Point Pipe Securing Clip Modulator Coil Pump Securing Bracket

Fig. 32

Fig. 33 Linea 24 & 28 25

8.14 8.14.1 8.14.2

Pump Part No 10020437 See fig. 33 Gain general access as 8.4 Close heating flow and return valves (fig. 6), by turning 1/4 turn until indicating lines are horizontal. Pull lever on head of safety valve to drain primary circuit to boiler. Place cloth under pump to catch surplus water. HEAD ONLY Unscrew the 4 allen screws around the pump head. Pull head from base of pump and disconnect electrical leads. If replacement required, use the head from a standard 15-50 Grundfos COMPLETE PUMP Disconnect pipe union connection at front left corner of combustion chamber. See fig. 34 Disconnect push fit pipes from pump base by removing seecuring clips and pulling pipes free from base. See fig. 34 Remove screw from pump securing bracket. Grasp pump and pull upwards with slight twisting movement to release pump from manifold. Disconnect electrical leads from pump.
8.15.5 8.15.6 8.15.7 8.15.8 8.16 8.16.1 8.16.2 8.16.3 8.16.4 8.16.5 8.16.6 8.16.7 8.16.8 8.16.9
Disconnect cold water inlet valve from flow switch by undoing union. Disconnect union at top of flow switch and two electrical tab connectors. Undo lock nut securing flow switch to base frame and remove. Reassemble in reverse order. Hydraulic Manifold Gain general access as 8.4 Place receptacle or an absorbent pad below appliance to catch trapped water. Remove domestic hot water heat exchanger as 8.17. Remove motorised valve as 8.21.8. Release pressure switch from hydraulic manifold by removing retaining screw Remove cold water connecting pipe by undoing the unions at both ends. Disconnect flow tube union where it connects onto the hydraulic group. Remove pump as 8.14.5 Unscrew pressure gauge connection retaining screw and pull out pressure gauge connnection.

8.14.3 8.14.4

8.14.5

8.19.2

8.17.1 8.17.2 8.17.3 8.17.4 8.17.5
Switch OFF mains electricity and gain general access. Disconnect electricity supply and wiring for external controls from the appliance. See 5.7 Close heating flow and return valves (fig. 6) by turning 1/4 turn until indicating lines are horizontal. Pull lever on head of safety valve to drain primary circuit to boiler. Remove screws on large maintenance clip/s (fig. 14) and remove. Loosen screws on the small clip/s and disconnect flue. Disconnect all pipe unions at the base of the appliance. Lift appliance off upper bracket. Remove two screws retaining vessel securing strap at top. Disconnect expansion pipe at base of expansion vessel and lift vessel out of the appliance. Reassemble in reverse order, using new fibre washers.

8.19.3

8.19.4

8.19.5 8.19.6 8.19.7

8.17.6 8.17.7 8.17.8 8.17.9 8.18 8.18.1 8.18.2

8.19.8

8.18.3 8.18.4 8.18.5 8.18.6 8.19 8.19.1

8.20 8.20.1 8.20.2

Safety Valve Part No. 1806 Refer to figs.34 & 35 Gain general access as 8.4. Close heating flow and return valves (fig. 6) by turning 1/4 turn until indicating lines are horizontal. Pull lever on head of safety valve to drain primary circuit to boiler. Disconnect safety valve discharge pipe. Loosen grub screw at base of safety valve and pull forwards releasing valve from O' ring seal. Replace in reverse order.
8.21 8.21.1 8.21.2 8.21.3 8.21.4 8.21.5
Removal of Electrical Components Ensure electricity is switched off at main isolator and gain general access as 8.4. Water pressure switch Fig. 1, no. 22 Gain general access as 8.4 Carefully remove the electrical connections to the water pressure switch Extract locking pin and remove the water pressure swutch from the hydraulic manifoldRemove printed circuit board cover by releasing 5 securing screws. Reassemble in reverse order ensuring correct location of electrical connctions. (see fig. 41&43 for electrical conncections)

8.20.3 8.20.4 8.20.5

8.21.6

Domestic Heat Exchanger

Domestic Hot Water Thermistor

Water Flow Regulator

Domestic Hot Water Heat Exchanger Retaining Screws
Diverter Valve and Flow Switch Manifold

Pressure Switch

Safety Valve Diverter Valve Bobbin Diverter Valve Cover

Motorised Valve

Fig.35

8.21.7 8.21.8 8.21.9

Motorised Valve Gain general access as 8.4 Release motorised valve by removing retaining clip.
8.21.32b DOMESTIC HOT WATER Close cold water inlet stopcock. See fig.6 and 6.3.3.4. Open lowest draw-off or drain tap on hot water system. 8.21.33 Remove ignition control box as 8.12 8.21.34 Pull off electrical plug connection from thermistor. 8.21.35 Unscrew thermistor from pocket. 8.21.36 Reassemble in reverse order. 8.22 8.22.1 8.22.2 Pressure Gauge Part No 1857 Gain general access as 8.4 Close heating flow and return valves (fig.6) by turning 1/4 turn until indicating lines are horizontal. Pull lever on head of safety valve to drain primary circuit to boiler. Trace capillary from back of pressure gauge to connecting point on brass manifold. Unscrew the retaining screw beside the capillary tube entry to the manifold. Pull out capillary tube from manifold. Squeeze plastic locking lugs behind fascia and press gauge from aperture. Reassemble in reverse order following original route for capillary tubes and ensuring locking lugs are located in the grooves.

NOTE: L-N-E CONNECTION IS ADVISABLE

blue brown

purple

brown brown

orange

brown black

Linea 24 & 28 Fig. 41
grey grey blue blue brown black red brown red
NOTE: L-N-E CONNECTION IS ADVISABLE CONTROL SWITCHING OF TIME CLOCK AND ROOM THERMOSTAT IS 230 V.a.c.
GENERAL LAYOUT & ILLUSTRATED WIRING DIAGRAM
white-red white brown blue
GREEN white-light blue white-brown white-purple RED
PRELIMINARY ELECTRICAL SYSTEM CHECKS
A. EARTH CONTINUITY CHECK - appliance must be electrically disconnected - meter set on (ohms) x 1 scale and adjust zero if necessary. a) Test leads from any appliance earth point to earth pin on plug - resistance should be less than 0.1 (ohm). If the resistance is greater than 0.1 (ohm) check all earth wires for continuity and all contacts clean and tight. B. SHORT CIRCUIT CHECK - appliance electrically disconnected, all switches ON (including stats) a) meter set on (ohms) x 1 scale. Test leads from L to N in appliance terminal strip/block - if meter reads 0 then there is a short circuit. b) meter set on (ohms) x 100 scale Repeat test with leads from L to E. If meter reads less than (infinity) there is a fault. NOTE - Should it be found that the fuse has failed but no fault is indicated, a detailed continuity check (i.e. by disconnecting and checking each component) is required to trace the faulty component. It is possible that a fault could occur as a result of local burning/arcing but no fault could be found under test. However, a detailed visual inspection should reveal evidence of burning around the fault. C. POLARITY CHECK Appliance connected to mains supply and meter set on 300V ac scale. Test at appliance terminal strip:a) Test leads from L to N - meter reads approx 230V ac b) Test leads from L to E ( ) - meter reads approx 230V ac c) Test leads from N to E ( ) - meter reads from O-15V ac* Thus the terminal marked L is the live terminal. If the low* V ac reading is given on terminals other than N to E ( ) there is an electrical fault. Repeat the test at the appliance plug/inlet spur to check the wiring system up to the appliance and rectify any fault. If necessary repeat the test at the supply system socket/spur - if the fault also occurs at this stage then there is a house system fault which requires attention by the ELECTRICITY AUTHORITY. The customer should be warned not to use the appliance until this examination has been carried out. D. RESISTANCE TO EARTH CHECK Appliance must be disconnected from mains supply and meter set on (ohms) x 100 scale. All switches, including stats, ON - Test leads from L to E - if meter reads other than infinity () there is a fault which should be isolated. A detailed continuity check is required to trace the faulty component. IMPORTANT - This series of checks are the first electrical checks to be carried out during a fault finding procedure. On completion of the service/fault finding task which has required the breaking and remaking of electrical connections then the checks - A. Earth Continuity. C. Polarity and D. Resistance to Earth - must be repeated.

SECTION 11

L.P.G. INSTRUCTIONS

11.1 Gas Rates (LPG)

Min. Gas Rate Max. Gas Rate 11.2 Burner Details (LPG) 1.52 litres/h 4.12 litres/h
1.63 litres/h 4.85 litres/h
Main Burner Main Burner Injectors Burner Pressure Max. Rate Burner Pressure Min. C/H Burner Pressure Min. DHW Burner Pressure Soft Light 11.3 RELATED DOCUMENTS BS 6798 BS 5449 BS 5546 BS 5440 BS Polidoro NPx 0.77 36.0 mbar 6.5 mbar 5.1 mbar 16.7 mbar
Polidoro NPx 0.77 36.0 mbar 5.5 mbar 4.3 mbar 16.7 mbar

Part 1

Part 1 Part 1
Boilers of rated input not exceeding 60kW Forced circulation hot water systems Installation of gas hot water supplies for domestic purposes. Flues Domestic Butane & Propane Gas burners in permanent dwellings
GAS SUPPLY A gas supply should be connected to the boiler by a competent L.P.G. installer and should be of sufficient size to supply the boiler at its maximum output. An existing supply should be checked by the installer or L.P.G. supplier to ensure that it can deal with the rate of gas supply required for all the appliances when they are in use at the same time.

11.6.4

Locate the main burner pressure test point (fig. 20) and slacken the screw half a turn in an anti clockwise direction. Attach a suitable pressure gauge as described at 6.6.5. IMPORTANT: Before measuring gas pressures it is imperative that the protective cover over the gas valve adjustment screw is removed. (Fig. 37) Turn on electricity supply. Turn mode selector switch to the position and fully open a domestic hot water tap to operate boiler in dhw mode. Adjust hot water control knob to its maximum setting.

11.5 11.5.1

GAS SUPPLY INSTALLATION Inspect the entire installation including the meter, test for soundness and purge. CHECK BURNER PRESSURE The heat inputs for high and low gas rates are factory set to the maximum values given in section 11.2 but it is necessary to check/ adjust this when commissioning the appliance. Turn off the main electrical supply. Gain access to the interior as instructed in 5.3.1 5.3.2. Gain access to the electrical terminals as 5.7.2. Ensure the Jumper at point JP8 is removed. 11.6.5

11.12 11.13 11.14

energizing home heating

Vokra Ltd.

Catherine House, Boundary Way, Hemel Hempstead, Herts, HP2 7RP Email: enquiries@vokera.co.uk Web: www.vokera.co.uk General Enquiries - Tel: Fax: Technical Advice - Tel: 0520 Spare Parts - Tel: 6820 After Sales Service - Tel: 0220

Vokra Ireland

West Court, Callan, Co Kilkenny Tel: Fax: 056 55060
Vokra Ltd. reserve the right to change the specifications without prior notice. Consumers statutory rights are not affected. A Riello Group Company

COLLECTIVE MARK

Vokra supports Benchmark
Cod. 10023216 - 21/02 - Ed. 3

2.2 2.2.1

2.4 2.4.1
NOTE Fig. 2 A KEY: A B C D 2 B C D
Central Heating Return. Central Heating Flow. Hot Water Outlet. Cold Water Inlet.
NOTE: Pressure switch. Senses water pressure in the primary circuit and operates the pressure switch (15) Linea Plus AG

SECTION 3

TECHNICAL DATA
Concentric Flue Bend Reduction in flue length for each bend 0.5 m 1.0 m
Units Dimensions and values are given in the preferred Sl Units with Imperial units in brackets where applicable. Dimensions and Contents
Plus AG Height Width Depth Weight dry Weight full 820mm (32.3) 500mm (19.7) 355mm (14.0) 48kg (105.6lb) 51kg (112.2lb)
Twin Flue Bend 3.5 Reduction in flue length for each bend 1.0 m 1.0 m
Water content: 3 litres (.66 gals) for further dimensions see figs 12 - 16 3.3 Connection sizes Heating flow and return: Nut and olive for 22mm o.d. Cold water inlet: Nut and olive for 15mm o.d. Hot water outlet: Nut and tail for 15mm o.d. Gas Service: Nut and tail for 15mm o.d. Safety valve outlet: 15mm comp.or capillary Flue outlet/Air inlet: nom dia 60/100mm specially supplied with boiler (concentric). Flue outlet/Air inlet: nom dia 80/80mm specially supplied with boiler (twin). 3.4 3.4.1 Installation Requirements Clearances (Horizontal or Vertical Flue) Minimum - above casing 225mm (9in) Minimum - below casing 200mm (8in) Minimum In front 600mm (24in) Minimum - At sides 12mm (1/2in) from casing Maximum heating system contents approx. 76.4 litres (16.8 gals). Acceptance capacity of expansion vessel 10 litres (2.2 gals). Means of filling sealed system: to accord with BS and/or local Water Authority requirements. The standard concentric horizontal flue allows a maximum length of duct as follows: Rear flue: 700mm (wall thickness) Side flue: 890mm (to centre line of boiler). Using extension tubes the flue may be extended to the following lengths. Concentric Horizontal Vertical Plus AG 3.0m 3.0m
Electrical Details Mains supply 230v ~ 50Hz Fused 3A Internal fuse rating F2A and T100mA Power consumption:160W Performance and Limitations Plus AG Max. input 34.9 kW (119,080 Btu/h)(net h/w) Max. inpu 38.7 kW (132.050Btu/h)(grossh/w) Max. input 34.9 kW (119.080 Btu/h)(net c/h) Max. input 38.7 kW (132.050Btu/h)(gross c/h) Min. input 9.95 kW (34.052 Btu/h)(net)(c/h) Min. input 9.95 kW (34.052 Btu/h)(net)(h/w) Min. input 11.07 kW (37.770 Btu/h)(gross)(c/h) Min. input 11.07 kW (37.770 Btu/h)(gross)(h/w) Max. output 32.00 kW (109,200 Btu/h)(h/w) Max. output 32.00 kW (109,200 Btu/h)(c/h) Min. output 9.0 kW (30,700 Btu/h)(h/w) Min. output 9.0 kW (30,700 Btu/h)(c/h) Central heating output range Max. 32.0 kW (109,200 Btu/h) Min. 9.0 kW (30,700 Btu/h) Nominal hot water production Temp. rise of 30C 15.3l/min. Temp. rise of 35C 13.1l/min. Gas Pressures Max. gas pressure 10.1 mbar h/w Min. gas pressure 1.1 mbar h/w Gas Rate Max. 3.69m3/h 138.8 ft3/h (h/w) Min. 1.05 m3/h 35.6 ft3/h (h/w) Note: Use gross input values when gas rating the appliance Burner Details Main burner: Polidoro type Main burner injectors 16 x 1.35

3.4.3 3.4.4

Twin (+ concentric terminal) Plus AG 14/14m 14/14m 3.7

Horizontal Vertical

Working Pressure Heating System Maximum 1.5bar/15m w.g./50ft w.g. Minimum 0.15bar/1.5m w.g./5ft w.g. Safety valve setting 3bar/30m/102ft w.g. Flow Rates Min. waterflow (dhw) 2.0l/min. (0.45 gal/min) Min central heating flow rate through appliance 350litres/hr (1.28 gal/min)
3.8 The reduction in flue length for each bend used is listed opposite.
Working Pressure Hot Water System Maximum 6.0 bar/90psig Minimum 0.6 bar/ 7psig For LPG instructions see page 62.
Central Heating Pump Duty Fig.3 indicates the flow rate available plotted against system pressure drop. N.B. When using this graph apply only the pressure drop of the system. The curve has been modified to allow for the pressure drop through the appliance.

Fig. 3

SECTION 4

GENERAL REQUIREMENTS

A compartment used to enclose the boiler must be designed and constructed specifically for this purpose. An existing cupboard or compartment may be used provided that it is modified for this purpose. Details of essential features of cupboard/ compartment design including airing cupboard installations are given in BS 6798:1987. This appliance is not suitable for external installation. 4.3 Gas Supply A gas meter is connected to the service pipe by the gas supplier. An existing meter should be checked, preferably by the gas supplier, to ensure that the meter is adequate to deal with the rate of gas supply required for all appliances it serves.
General Requirements This appliance must be installed by a competent person in accordance with the Gas Safety (Installation & Use) Regulations 1998.
Related Documents The installation of this boiler must be in accordance with the relevant requirements of the Gas Safety (Installation & Use) Regulations 1998 the Local Building Regulations, the current l.E.E. Wiring Regulations, the by-laws of the local water undertaking, and in Scotland, in accordance with the Building Standards (Scotland) Regulation. In Ireland the local building regulations (IE). It should be in accordance also with any relevant requirements of the local authority and the relevant recommendations of the following British Standard Codes of Practice:
BS 6891 BS 6798 BS 5449 BS 5546 BS 5440 BS 5440 BS 7074
Part 1 Part 1 Part 2 Part 1
Low pressure installation pipes. Boilers of rated input not exceeding 60kW. Forced circulation hot water systems Installation of gas hot water supplies for domestic purposes (2nd family gases). Flues. Flues & Ventilation. Application, selection & installation of expansion vessels & ancillary equipment for sealed water systems.
Location of Appliance The combination boiler may be installed in any room or internal space, although particular attention is drawn to the requirements of the current l.E.E. Wiring Regulations, and in Scotland, the electrical provisions of the Building Regulations applicable in Scotland, with respect to the installation of the combination boiler in a room or internal space containing a bath or shower. Where a room-sealed appliance is installed in a room containing a bath or shower, any electrical switch or appliance control, utilising mains electricity, should be located in such a position that it cannot be touched by a person using the bath or shower. The location chosen for the boiler must permit the provision of a satisfactory flue and termination. The location must also permit an adequate air supply for combustion purposes and an adequate space for servicing and air circulation around the boiler. Where the installation of the boiler will be in an unusual location special procedures may be necessary and BS 6798:1987 gives detailed guidance on this aspect.

Installation pipes should be fitted in accordance with BS 6891:1988. Pipework from the meter to the boiler must be of adequate size. Pipes of a smaller size than the boiler inlet connection should not be used. The complete installation must be tested for soundness as described in the above code. N.B. If the gas supply for the boiler serves other appliances ensure that an adequate supply is available both to the boiler and the other appliance when they are in use at the same time. 4.4 Flue System The terminal should be located where dispersal of combustion products is not impeded and with due regard for the damage or discoloration that might occur to building products in the vicinity (see fig 4). The terminal must not be located in a place where it is likely to cause a nuisance. In cold and/or humid weather water vapour may condense on leaving the flue terminal. The effect of such steaming must be considered.
For protection of combustibles, refer to BS 5440:1 where the terminal is less than 2m (6.6ft) above a pavement or platform to which people have access (including any balcony or flat roof the terminal must be protected by a guard of durable material). A suitable guard is available from Vokera Ltd. Part No 018, G.C. No. This guard must be fitted centrally over the terminal. Mark the positions of the fixings, drill the wall and secure using wall plugs and 3 of 1" No.8 plated screws. Fig. 4
Water Circulation (Central Heating) Detailed recommendations are given in S6798: 1987 and BS 5449: 1: 1990 (for smallbore and microbore central heating systems). The following notes are given for general guidance. Pipework Copper tubing to BS 2871:1:1971 is recommended for water pipe. Jointing should be either by capillary soldered or with compression fittings. Where possible, pipes should have a gradient to ensure air is carried naturally to air release points and water flows naturally to drain taps. It should be ensured as far as possible that the appliance heat exchanger is not a natural collecting point for air. Except where providing useful heat, pipes should be insulated to prevent heat loss and to avoid freezing. Particular attention should be paid to pipes passing through ventilated spaces in roofs and under floors.

4.6.1 4.6.2

By-Pass An automatic by-pass is incorporated in the boiler, but systems should be designed to ensure that with all radiators turned off a flow rate of at least 350 litres/hour (1.28 gals/min) is achieved through the system. See 6.9.4. System Design Figs 5 & 5a illustrates typical system layouts showing options of either, pipe connection from below as fig. 5, or pipe connection from above utilising the purpose made duct in the rear frame of the appliance. Draining Taps These must be located in accessible positions to permit the draining of the whole system. The taps must be at least 15mm nominal size and manufactured in accordance with BS 2879: 1980.
Terminal position for fan assisted boiler (minimum distance) mm A - Directly below an open window or other 300 opening (e.g. air brick) B - Below gutters, soil pipes or drain pipes 25 C - Below eaves 25 D - Below balconies or car port roof 25 E - From vertical drain pipes and soil pipes 75 F - From internal or external corners 25 G - Above ground or below balcony level 300 H - From a surface facing a terminal 600 I - From a terminal facing a terminal 1200 J - From an opening in the car port (e.g. door window) into dwelling. 1200 K - Vertically from a terminal on the same wall 1500 L - Horizontally from a terminal on the same wall 300 M - Horizontally from a vertical terminal to a wall 300 N - Horizontally from an opening, airbrick, openable window, etc. 300
NOTE: The flue must be terminated in a place not likely to cause a nuisance. 4.5 Air Supply The following notes are intended for general guidance. The room sealed fan flued boiler does not require a permanent air vent for combustion air supply. Where installed in a cupboard or compartment ventilation is not required.

Fig. 5

Fig. 5a
N.B. Vokra Ltd recommend a 2-pipe system. Single pipe systems are more liable to be troublesome unless carefullly designed and installed. Linea Plus AG 7
Air Release Points These must be fitted at all high points where air will naturally collect, and must be sited to facilitate complete filling of the system. The appliance has an integral sealed expansion vessel to accommodate the increase of water volume when the system is heated. It can accept up to 10 litres of expansion water. If the appliance is connected to a system with an unusually high water content. Calculate the total expansion and add additional sealed expansion capacity as appropriate. In general, modern systems will present no problem.
Filling Point A method for filling the system and replacing water lost during servicing is provided on the appliance. This method complies with the Water Supply (Water Fittings) Regulations 1999.
Filling Loop Cold water Inlet Stopcock/ filling valve C/H Flow Valve
Electrical Supply The appliance is supplied for operation on 230V ~ 50Hz electricity supply. It should be protected with a 3-amp fuse. THIS APPLIANCE MUST BE EARTHED. The method of connection to the mains electricity must allow complete isolation from the supply. The preferred method is by using a fused double pole switch with a contact separation of at least 3mm. The switch must supply ONLY the appliance and immediate electrical control circuits (e.g. programmer / room thermostat) Alternatively, use an unswitched shuttered socket outlet with a fused 3-pin plug both complying with BS 1363.

Reduction for bend

Bend 45 bend 90 bend Reduction in maximum flue length for each bend 1.0 metre 1.0 metre

Twin flue accessories

Part No. Description Horizontal flue terminal Vertical flue terminal Twin adapter kit Pitched roof flashing plate Flat roof flashing plate Condensate drain kit 0.25m extension (pair) 0.5m extension (pair) 1.0m extension (pair) 2.0m extension (pair) 45 bend (pair) 90 bend (pair) Twin bracket (5) Single bracket (5) Length 1.0 metre 1.0 metre N/A N/A N/A N/A 250mm 500mm 1000mm 2000mm N/A N/A N/A N/A

Fig. Linea Plus AG

Mounting the boiler The fixing holes for the wall-mounting bracket & jig should now be drilled and plugged, an appropriate type and quantity of fixing should be used to ensure that the bracket is mounted securely. Once the bracket has been secured to the wall, mount the appliance onto the bracket & jig. 5.5.3.1 Installation of twin adaptor kit (fig. 15)
The condensate drain kit must be fitted within 1 metre of the appliance flue outlet. It is recommended that the condensate drain kit should be fitted in the vertical plane, however it can be fitted horizontally with care. Fit the first bend to the condensate drain kit or exhaust connection manifold by firmly pushing in to position. Using the two holes in the exhaust connection manifold as a guide, drill a 3mm hole in each and secure using the screws provided. Connect the air inlet pipe to the air baffle as above. The twin flue pipes extensions and accessories can now be installed by pushing together (the plain end of each extension or bend should be pushed approximately 50mm into the female socket of the previous piece). The condensate drain trap must be connected to the drain in accordance with Building Regulations or other rules in force
Fig. 15 Remove or discard the flue restrictor ring from the appliance flue outlet (see fig. 1). Insert the small restrictor ring (supplied with the twin adapter kit) if the total flue length including the allowance for any bends is less than 8 metres. Insert the exhaust connection manifold onto the appliance flue outlet. Place the silicone seal (supplied with twin adapter kit) over the rim of the exhaust connection manifold. Remove one of the blanking plates (located to the left & right of the appliance flu Remove one of the blanking plates (located to the left & right of the appliance flue outlet) and using the same screws install the air baffle. 5.5.3.2 Installation of condensate drain kit (fig. 16)

Earth Screw

Factory Fitted Link Between = & TA
Safety Valve Discharge Connect a 15mm pipe to the discharge outlet of the appliance. The discharge should terminate facing downwards outside the building in a position where discharging (possibly boiling) water will not create danger or nuisance; but in an easily visible position.

5.7 5.7.1

Electrical Connections The electricity supply must be as specified in 4.7. If controls external to the appliance are required, design of the external electrical circuits should be undertaken by a competent person. See Section 10 for further advice. Fig. 18a Mains Input and External Controls Terminal Block 15
Pass the cable through one of the cord anchorage points and connect the wires Brown to L, Blue to N, and Green/Yellow to. Arrange the cable so that should the cable slip the anchorage the current carrying conductors become taut before the earthing conductor. Securely tighten all terminal screws and arrange the cable with slack between the cable anchor and the terminal block. Tighten the cord anchorage screw until the cable is secure. Neatly arrange the external cable in such a way that unrestricted opening of the controls fascia is possible without strain on the cable. External controls may be wired from terminals TA to TA after removing the factory fitted link (see fig. 18 & pages 49 - 52 for further details). If a neutral is needed use the terminal marked N on the terminal strip. DO NOT CONNECT ANY WIRES TO THE TERMINAL STRIP MARKED 'S' '-' 'POS' 'POS' When connecting wires to the terminal strip it is possible to remove the terminal strip from the circuit board: Grasp the terminal strip firmly and slide up to clear pcb. See fig.21. When refitting the terminal strip it is important that it is replaced correctly (with the screws facing left). Section 10 gives details of fitment for external and internal controls (ie Vokera time clock). If required pass the external controls cable through the spare cord anchorage and arrange the cable so that should the cable slip the anchorage the current carrying conductors become taut before the earthing conductor.

Main Burner Test Point

Incoming Gas Pressure Test Point

Fig. 19

Normal Operating Position
Closed Position Filling Position

Fig. 20

Do not connect wires to this terminal strip

Fig. 21

Controls terminal strip

SECTION 6

COMMISSIONING
6.3.3 Initial flushing of Pipework The whole of the heating system must be flushed both cold and later hot as detailed in 6.10. Open all radiator or heating valves and the appliance central heating valves. Drain the boiler and system from the lowest points. Open the drain valve full bore to remove any installation debris from the boiler prior to lighting. Refill the boiler and heating system as described in 6.3.2 6.3.4 6.3.4.1 6.3.4.2 Setting the System Design Pressure The design pressure should be a minimum of 1 bar and maximum 1.5 bar. The actual reading should ideally be 1 bar plus the equivalent height in metres to the highest point of the system above the base of the appliance. (Up to the maximum of 1.5 bar total). N.B. The safety valve is set to lift at 3bar/ 30m/ 45psig. 6.3.4.3 To lower the system pressure to the required value, pull lever on head of safety valve (14) a quarter turn to release water until the required figure registers on the gauge (31). Filling the Hot Water System Close all hot water draw-off taps. Turn filling/inlet valve to the normal operating position (vertically up). See fig. 20 Slowly open each draw-off until clear water is discharged. Checking Electricity Supply Carry out preliminary checks for continuity, polarity, and resistance to earth (see page 61), gaining access as required according to 5.7.2 in this manual. Leave the appliance with the control fascia closed and with the mains electricity switched OFF Lighting the Boiler Ensure flow and return valves are open. (6.3.2.1) If external and/or internal controls are fitted (e.g Timeclock and/or Room thermostat) ensure they call for heat. The commissioning of the appliance may be easier if the external/ internal controls are disconnected and terminals TA & TA are linked. (For access procedure turn off electricity and refer to 5.7.2 for instructions). 6.5.2 6.5.3 6.5.4 Switch on the mains electricity and turn the on / off / mode switch (25) to Set the c/h control knob (28) to the highest setting. The appliance will go through an ignition sequence and the burner will light.
Where the text bears identifying numbers in brackets, refer to figs. 1 and 2 unless otherwise instructed. Gas Supply Installation Inspect the entire installation including the meter. Test for soundness and purge, all as described in BS6891:1988. Central Heating Systems IMPORTANT DO NOT RELEASE AIR FROM THE RED SEALED EXPANSION TANK. It is charged with air at the factory from.75 -.80 bar (11 - 12psig) Initial filling of the System See 3.4.3. Open central heating flow and return valves. Unscrew black cap on automatic air release valve (18) one full turn. (Leave open permanently). Close all air release taps on the central heating system. Identify the filling/inlet valve found at the base of the appliance. See fig.6. The filling loop may have been disconnected from the filling/inlet valve and heating flow valve. If so reconnect unscrewing the caps as necessary. The filling/inlet valve has 3 positions. (Fig. 20) i) Vertically up - normal operating position. ii) Turn to the left to horizontal - closed position. iii) Vertically down - Filling position. To fill, slowly turn the handle of the filling/inlet valve from the closed position towards the filling position. Mains water will be heard to enter the system/boiler. As the water enters the system/boiler the pressure gauge will be seen to rise. Pressurise to between 1bar & 1.5bar when the system is cold. DO NOT OVERPRESSURISE. Once the desired pressure is achieved turn the filling/inlet valve back to the closed position. Starting with the lowest radiator open each air release tap in turn closing it only when clear water, free of bubbles, flows out. In the same way release air from any high points in the pipework. Continue filling the system until at least 1.0 bar registers on the gauge then turn the handle of the filling/inlet valve back to the closed position. Inspect the system for water soundness and remedy any leaks discovered.

6.11.3

Set the adjustable stopcock to restrict the maximum flow of water and achieve a temperature rise acceptable to the end user. The flow of water should activate the domestic hot water flow switch (13) and drive the diverting valve (16) to its hot water position thus heating the domestic water flowing through the dhw heat exchanger. At the same time the pump and fan are activated lighting the burner on maximum rate. If the burner does not light, check that the water flow rate is above the minimum required to operate the domestic hot water flow switch (13) 2.0 litres/min (0.45 gals/min). The temperature of the water will depend on the rate at which it flows. The temperature of water at the tap can be varied by adjusting the water flow rate at the tap up to the maximum predetermined quantity.The hot water temperature control knob (24) will govern the maximum temperature. When the appliance is being used in hot water mode the temperature indicator (27) indicates the temperature of the hot water leaving the appliance.

6.11.4

6.8 6.8.1

6.11.5

6.9 6.9.1

6.11.6

6.9.2 6.9.3

6.11.7

It is best to set for the lowest acceptable temperature since the user can gain higher temperatures by restricting flow at the tap. N.B. If the cold supply is subject to large fluctuations or is above the permitted maximum a suitable pressure/flow regulator should be fitted in the cold water supply to the appliance.

6.11.8

6.10 6.10.1
Final Flushing of the Heating System The system should be flushed in accordance with BS 7593: 1992.Turn on the boiler for central heating and allow the boiler and system to reach temperature. Turn off the boiler and drain the system whilst still hot. Refill the boiler and heating system as described in 6.3.2. Although not necessary for correct operation of the boiler, an inhibitor may be added at this point. Contact the inhibitor manufacturer for further information concerning application and dosage. 6.11.9
Turn the appliance mode selector switch (25) to the position. Slowly close the tap to reduce the rate of draw to above the minimum approx. 2.0 litres/min., (0.45 gal/min.) Rotate the dhw control knob to ensure the appliance modulates at its various setting. Close the draw-off tap still further. The burner should stop when the rate falls below approximately 2.0 litres/min. (0.45 gal/min.).

Pipe Securing Clip

Pump Securing Bracket

Modulator Coil

Protective cover

Fig. 31

Fig. 32 Linea Plus AG 25

8.14 8.14.1 8.14.2

Pump Part No. 0438. Gain general access as 8.4. Close heating flow and return valves (fig. 6), by turning 1/4 turn until indicating lines are horizontal. Pull lever on head of safety valve to drain primary circuit to boiler. Place cloth under pump to catch surplus water. HEAD ONLY Unscrew the 4 allen screws around the pump head. Pull head from base of pump and disconnect electrical leads. If replacement required, use the head from a standard 15-60 Grundfos. COMPLETE PUMP Disconnect pipe union connection at front left corner of combustion chamber. See fig. 33. Disconnect push fit pipe from pump body by releasing pump securing clip and pulling pipe free from body. See fig. 32. Remove screw from pump securing bracket. Grasp pump and pull upwards with slight twisting movement to release pump from manifold. Disconnect electrical leads from pump.
8.15.5 8.15.6 8.15.7 8.15.8 8.16
Disconnect cold water inlet valve from flow switch by undoing union. Disconnect union at top of flow switch and two electrical tab connectors. Undo lock nut securing flow switch to base frame and remove. Reassemble in reverse order. Combined Diverter Valve & Pressure Switch Refer to fig. 33. Gain general access as 8.4. Place receptacle or an absorbent pad below appliance to catch trapped water. Remove domestic hot water heat exchanger as 8.17. Remove diverter valve as 8.21.8. Release pressure switch from the hydraulic group by removing one retaining screw on bracket. Remove cold water connecting pipe by undoing the unions at both ends. Disconnect flow tube union where it connects onto the hydraulic group. Disconnect expansion vessel pipe. Unscrew pressure gauge connection retaining screw and pull out pressure gauge connnection.

8.14.3 8.14.4

8.16.1 8.16.2 8.16.3 8.16.4 8.16.5

8.14.5

8.14.6

8.14.7 8.14.8

8.16.6 8.16.7 8.16.8 8.16.9

8.14.9

8.14.10 Remove pump securing bracket from pump housing and transfer to new body. 8.14.11 Reassemble in reverse order. Reconnect electrical leads Brown to L, Blue to N and Green to E. 8.15 8.15.1 8.15.2 8.15.3 8.15.4 Domestic Flow Switch Refer to fig. 33. Gain general access as 8.4. Place receptacle or an absorbent pad below appliance to catch trapped water. Close cold water inlet stopcock. See fig.6 and 6.3.2.4. Open lowest draw-off or drain tap on hot water system.
8.16.10 Disconnect safety valve discharge pipe and heating valve unions. 8.16.11 Remove retaining screw securing hydraulic group to frame. 8.16.12 Withdraw hydraulic group from appliance. See fig. 34 for further disassembly.

Pump Pipe Union

Gas Valve & Ignition Control Box

FAULT FINDING GUIDES

On the following pages are the fault finding guides. Be sure to read the notes below before begining any fault finding NOTES: 1. 2. 3. To ensure correct fault diagnosis it is important that these guides are carried out in the set order. Check the electrical supply polarity is correct before carrying out fault finding (lockout will occur if the polarity is reversed). To ensure that internal/external controls (if fitted) do not interfere with fault finding, disconnect the wires from terminals TA & TA (labelling them in the process to ensure correct reconnection) and provide a solid link between TA & TA. 33
VOKERA LINEA PLUS AG Rev. 1 08/03/2000 TEST A : CHECKING OPERA TION OF ELECTRONIC CONTROL BOARD AT START UP IS THE 3 WAY VAL VE IN DHW POSITION? YES YES
SWITCH ON/OFF SELECTOR TO DHW POSITION
MAINS ON 3 WAY VALVE BETWEEN TERMINALS M11.1 & M11.3 ON PCB

GREEN LED ALIGHT

NO TURN ON HOT TAP
YES CHECK &/OR REPLACE WIRING OR CONNECTIONS AND 3 WAY VALVE

REPLACE PCB

PUMP RUNNING

IS THERE 5 Vdc

FAN RUNNING
IS THERE 0 Vdc BETWEEN TERMINALS M5.5 & M5.6 ON PCB MAINS ON FAN CONNECTOR M12.1 & M12.2
BETWEEN TERMINALS M5.5 & M5.6 ON PCB

REPLACE CONTROL BOARD

CHECK WIRING AND CONNECTIONS OR DHW FLOW SWITCH

YES NO

MAINS ON FAN
MAINS ON PUMP CONNECTOR M15.1 & M15.2 YES

REPLACE FAN

CHECK &/OR REPLACE WIRING AND CONNECTIONS IS THERE 0 - 1 Vdc BETWEEN TERMINALS M3.11 & M3.10 ON PCB YES

MAINS ON PUMP NO YES

REPLACE WIRING OR CONNECTIONS

REPLACE PUMP

CHECK FLUE GAS TUBE, DIFFERENTIAL ANALOG PRESSURE SWITCH AND WIRING OR CONNECTIONS
IS THERE 24 Vdc BETWEEN TERMINALS M5.3 AND M3.3 ON PCB YES
REPLACE THE CONTROL BOARD
IS THERE 24 Vdc BETWEEN TERMINALS M5.3 ON PCB & WHITE WIRE ON HIGH LIMIT THERMOSTAT
CHECK WIRING AND CONNECTIONS
IS THERE 24 Vdc BETWEEN TERMINALS M5.3 ON PCB & RED WIRE ON HIGH LIMIT THERMOSTAT
RESET THE HIGH LIMIT THERMOSTAT
IS THERE 24 Vdc BETWEEN TERMINALS M5.3 AND M3.4 ON PCB NO
CHECK WIRING AND CONNECTIONS GREEN LED LIGHT NO
IS THERE 24 Vdc BETWEEN TERMINALS M5.3 AND M3.5 ON PCB
NO CHECK COMBUSTION AND CHECK &/OR REPLACE BURNER THERMISTOR AND WIRING

YES RESTART THE TEST

CHECK WIRING AND CONNECTIONS, HIGH LIMIT THERMOSTAT OR PCB
5 Vdc BETWEEN TERMINALS M2.1 & M2.2 ON DISPLAY BOARD

IS RED LED FLASHING

NO FAULT CODE SHOWING
5 Vdc BETWEEN TERMINALS M9.1 & M9.2 ON CONTROL BOARD

REPLACE DIGITS BOARD

YES CHECK AND/OR REPLACE WIRING OR CONNECTIONS WITH DISPLAY BOARD

LED ASSEMBLY OK

BICOULORED
MAINS PRESENT BETWEEN M16.L & M16.N ON CONTROL BOARD
REPLACE THE BICOULORED LED ASSEMBLY
NO CHECK FUSES F1 AND F2 ON CONNECTION BOARD
REPLACE THE DIGITS BOARD FAULT CODE 01 SHOWING
RECHECK SUPPLY FUSE & CONNECTORS TO BOILER TERMINALS
YES SWITCH ON/OFF SELECTOR TO OFF POSITION YES FUSE OK
REPLACE CONTROL BOARD FAULT CODE 02 SHOWING YES SWITCH MODE SELECTOR TO DHW POSITION

REPLACE FUSE

RESTART THE HIGH LIMIT STAT RESTART THE TEST GREEN LED LIGHT YES GREEN LED LIGHT YES IGNITION CONTROL OK NO YES
CHECK WIRING AND CONNECTIONS ,HIGH LIMIT THERMOST. AND CONTROL BOARD

RESTART THE TEST

REPLACE IGNITION CONTROL
VOKERA LINEA PLUS AG Rev. 1 08/03/2000 TEST B : CHECK CONTROL IN DHW MODE
TURN MODE SELECTOR SWITCH TO DHW. DHW STA AT MAX. T

TURN ON TAP

DOES BURNER LIGHT YES
IS THERE A VOL TAGE >4 Vdc BETWEEN TERMINALS M3.10 & M3.11 ON PCB
CHECK BOILER STARTUP: TEST A

IS FAN ON?

NO CHECK FAN, WIRING AND CONNECTIONS, DIFFERENTIAL ANALOG PRESSURE SWITCH AND CONTROL BOARD
IS D.A.P.S. OK? YES TURN DHW THERMOSTAT AT MIN.

CHECK FLUE VENTURI TUBE

REPLACE DIFFERENTIAL ANALOG PRESSURE SWITCH
DO BURNER AND FAN SWITCH OFF
WAIT WATER FLOW TEMPERATURE >40 C
YES TURN DHW THERMOSTAT AT MAX.
IS WATER FLOW TEMPERATURE >40 C
VOKERA LINEA PLUS AG Rev. 1 08/03/2000
SWITCH ON BOILER AND SELECT MODE TO WINTER C/H THERMOSTAT A T MAX.
TEST C: CHECK CONTROL IN C/H MODE
MAKE A LINK BETWEEN PIN M16.TA AND M16.TA ON CONTROL BOARD
YES DOES BURNER LIGHT NO CHECK BOILER STARTUP TEST A
IS THE 3 WA VALVE Y ON CH POSITION?
YES CHECK &/OR REPLACE 3 WAY VALVE
MAINS PRESENT BETWEEN M11.1 & M11.2 ON CONTROL BOARD

NO REPLACE CONTROL BOARD

NO IS FAN ON?
NO CHECK FAN, WIRING AND CONNECTIONS, DIFFERENTIAL ANALOG PRESSURE SWITCH AND CONTROL BOARD NO

IS D.A.P.S. OK? YES

TURN CH THERMOSTAT TO MIN.
DO BURNER AND FAN SWITCH OFF YES
NO IS WATER FLOW TEMPERATURE >40 C YES REPLACE CONTROL BOARD
WAIT WATER FLOW TEMPERA TURE >40 C
TURN CH THERMOSTAT AT MAX.

SPARK AT ELECTRODE

IS THERE MAIN BETWEEN TERMINALS

IGNITION YES

M14.1 & M14.2 ON PCB
IS THERE MAIN BETWEEN TERMINALS L & N ON IGNITION CONTROL

PLUS AG

52 Film for display Push-push cover Hole cap Protection film O ring Screw Selector knob kit Control knob kit Edge clip Nut Transformer Ignition module Wiring harness Wiring harness Wiring harness 1780
Expansion vessel Flexible pipe Heating distributor manifold Pipe DHW actuator Clip Water supply stop cock Flexible pipe Non return valve Connection Heating cock
Heating cock Pipe Nipple Water supply stop cock Water supply stop cock Washer Washer Clip Nut Nut Clip 1890
Heat exchanger Pipe Pipe Pump Wiring harness Domestic water heat exchanger Connection Non return valve Pipe Hight limit thermostat NTC sensor Pipe Pipe Flow governor Connection Bracket By-pass valve Pump lock key Venting plugs kit
Pressure switch Heat insulator O ring Automatic air vent bottle O ring Safety valve Motorized valve O ring connection Three way valve cover Fixing fork wrench Seating plate Three way valve overhault kit Spring Screw Washer Washer Washer Wiring harness Wiring harness 1873
Air box bottom NG Burner NP LPG burner NP Spark electrode Air box clip Cover Washer Glass Glass flange Gas valve solenoid Gas pipe Gas valve
Gas pipe Gas cock Washer Washer Nut Clip Air box side Air box side Burner thermostat Bracket Wiring harness Wiring harness 10021947 10022112

KEY DESCRIPTION

Pressure differential switch Silicone tube Brass cap Block with combustion analysis check Fan flue connection Clamp for 60 diam. tube Washer clamp Fan to flue connector Fan Hood assembly Combustion chamber assembly Combustion chamber back panel
Combustion chamber lateral panel Combustion chamber front panel Self tapping screw Depressure tube Pressure tube 1/8" lock nut Wiring harness Wiring harness 1870 10020529
ABLING AND DISABLING ELECTRONIC FUNCTIONS
Certain electronic functions on the Linea range of appliances can be abled or disabled according to customer preference. The selections can be made by the addition or removal of jumper tags situated on the printed circuit board. Refer to fig. 40 for jumper positions on printed circuit board. Hot Water Preheat Function: To disable remove jumper JP6 To able add jumper to JP6 C/H Delay Timer: To disable add jumper to JP9 To able remove jumper from JP9 Natural Gas / LPG For Nat gas add jumper to JP8 For LPG remove jumper from JP8 Jumpers JP1, JP2, JP3, JP4, JP5 and JP7 also exist on the printed circuit board DO NOT under any circumstances add or remove jumpers at these points. Spare jumpers are available from Vokera stockists. Part no. 7232.