DIGITAL ROOM THERMOSTAT

PRODUCT SPECIFICATION SHEET
The new DT90 family of digital room thermostats is a range of market leading products designed to provide comfort with economy in modern heating systems. Its large display and simple button interface make DT90 extremely easy to use. Energy efficiency is addressed by state-of-the-art TPI control performance and an ECO button energy saving feature. Applications include control of gas or oil-fired boiler systems, underfloor heating, electric heating and zoning systems. With a modern fresh look that complements any style of dcor, and a range of valued features for users and installers alike, DT90 sets the standard for simple environmentally-friendly room thermostats.

FEATURES

Energy saving TPI control performance Advanced self-learning control adapts to the environment and ensures close temperature control with minimum energy usage Slim modern styling Large high contrast display with easy-to-read characters Simple user interface Temperature setting procedure eliminates the risk of accidental setpoint change Display shows room temperature, with option to inquire about setpoint 5C to 35C setpoint range with 0.5C increments Temperature set using up or down buttons Off/standby button, allowing manual switch off, with frost protection active Adjustable off/standby setpoint 5C to 16C or DT90 can be set to off completely Battery powered by 2 x AA (LR6) alkaline cells Up to 4 years battery life (minimum 2 years), with battery low warning

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Simple battery change by unclipping front cover Installer Mode allows the thermostat to be customised for the application and the needs of the user NVRAM storage of setup parameters, ensuring these are never lost Setpoint limits can be programmed in 24230Vac SPDT potential-free contacts for simple 2-wire installation 8 A resistive, 3 A inductive switch rating Surface or switch-box mounting options Sensor fault self-diagnostics Heat/cool changeover operation mode possible
FEATURES UNIQUE TO DT90E ECO MODEL Energy saving ECO button allows user to change to a lower, energy saving setpoint for a timed period of their choosing (124 hours) Display shows countdown of time remaining in ECO energy saving mode
DT90 DIGITAL ROOM THERMOSTAT
CONTROLS / DISPLAY LAYOUT
frost protect indicator heating demand indicator
ECO mode active ECO countdown indicator setpoint change buttons

temperature display

ECO button setpoint indicator off/standby button fault indicator

battery low warning

off/standby indicator

ECO mode countdown timer

SPECIFICATIONS

ELECTRICAL

Power supply Battery life Battery low warning : 2 x 1.5V IEC LR6 (AA) Alkaline cells : Typically 4 years, minimum 2 years (with correctly specified alkaline cells) : Display will indicate when battery power reserve is low. Unit will continue to function for a minimum of 4 weeks after the first indication is given : SPDT (single pole double throw ) potential free : 230 V, 5060 Hz, 0.01 A to 8 A resistive, 0.1 A to 3 A inductive (0.6pf) : 24 V, 060 Hz, 0.01 A to 8 A resistive, 0.1 A to 3 A inductive (0.6pf) Relay life Wiring Wiring access : 100,000 operations minimum : Terminal block capable of accepting wires up to 2.5mm : Rear, top and left side Positive off ECO energy saving Fail-safe operation Temperature setting range Control form Proportional band Minimum on/off time Cycle rate

TEMPERATURE CONTROL

Sensing element : 10K (@25C ) NTC thermistor : 5C to 35C setpoint range in 0.5C increments : Self-learning TPI Fuzzy Logic algorithm : 1.5C adjustable up to 3C in 0.1C increments : 1 minute, adjustable up to 5 min in 1 min increments : Adjustable to suit the application 3, 6, 9, 12 cycles per hour
Switch type Electrical rating
Temperature : 0.5C (or better) at 20C, 50% load and control accuracy 3C /hour temperature ramp Frost protection : 5C when thermostat switched to off/standby, adjustable 5C to 16C : Frost protection not available in cooling mode : Positive off possible (no frost protection) by setting in Installer Mode : Setpoint default 18C, adjustable 5C to 35C : If temperature measurement system fails, unit will continue to operate on the assumption of a 10% load

ENVIRONMENTAL & STANDARDS
Operating temperature Shipping & storage temperature Humidity IP class Approvals : 0C to 40C : -20C to 55C : Humidity range 10% to 90% rh, noncondensing : IP30 : CE mark, complying with standards EN60730-1: 2001, EN60730-2-9: 2002 EN55014-1: 2001, EN55014-2: 1997 : WEEE & RoSH compliant : C-tick

METRICS

Dimensions (unit) Dimensions (pack) Weight (unit) Weight (pack) : 90 x 92 x 27mm : 93 x 94 x 46mm : 165g : 192g

ORDERING SPECIFICATION

Model DT90A1008 DT90E1012 Description Digital room thermostat Digital room thermostat with ECO energy saving feature Literature Multi-lingual Multi-lingual

MAIN FEATURES

Extra-Large Display The DT90 display is more than double the size of its predecessor, ensuring it is even easier to read and allowing more information to be displayed, when required. The large characters and high contrast screen are especially important for those with impaired vision. Simple Interface The user interface has been made as simple as possible to make DT90 very easy to use. Buttons have been labeled and to identify them as the means of increasing and decreasing (respectively) the setpoint temperature. The display normally shows the actual room temperature. When one of the buttons is first pressed, the setpoint temperature is shown flashing, accompanied by the and symbols. Further buttons presses will increase or decrease the setpoint in increments of 0.5C. Off/Standby Button, with Frost Protection The off/standby button allows DT90 to switch off the heating (or cooling) system at the touch of a button. To prevent accidental switch-off, the button must be held for 2 seconds to activate the change. When off, DT90 will maintain control at a frost protection setpoint, factory set to 5C but adjustable between 5 and 16C. If required, frost protection can be switched off, to provide a positive off function. These adjustments are made by entering the DT90 Installer Mode. Installer Mode The Installer Mode is where DT90 can be configured for different applications, and customized to meet the needs of the user. The operating properties that can be adjusted are called parameters, and these are described in detail on page 6. Parameters are as follows: Minimum on/off time Cycle rate Proportional band width Temperature measurement offset Upper setpoint limit Lower setpoint limit Energy saving ECO temperature (on DT90E only) Selection of heat/cool changeover operation Off/Standby setpoint Electric heat operation Reset all parameters to factory settings Installer Mode is entered via a sequence of button presses. The buttons are also used to scroll between t dt k h t th i l NVRAM Storage of Settings All parameter settings are stored in a special kind of memory called NVRAM so they will be retained indefinitely even if the batteries are removed. Advanced Self-learning TPI Control DT90 uses a self-learning fuzzy logic time-proportional control algorithm. This form of control is better than conventional PI control as it has a faster response and better performance in steady state conditions. It performs equally well in a wide range of different installations, and ensures energy savings by controlling closer to setpoint and minimising temperature overshoots. Additional Energy saving ECO feature In a heating system, one of the best ways to save energy is to reduce the setpoint temperature. The DT90 green ECO button provides a simple and convenient way of doing this for a period of time of the users choice. The ECO energy saving setpoint is pre-defined in the Installer Mode. The factory setting is 18C, but it can be adjusted (between 5C and 35C) to give a timed boost, if required. When the ECO button is pressed, the user is given the chance to set the time required at this new temperature, from 1 hour to 24 hours in 1 hour increments. The display indicates that ECO mode has been set, and will count down the time remaining in energy saving mode. Should they wish to readjust the temperature setting, they can do that too, using the and buttons. ECO mode is cancelled simply by pressing the ECO button again. 24 230V 8(3)A SPDT Potential Free Contact Rating The DT90 switching relay has a high specification and wide switching range, suitable for most domestic applications. As the thermostat is battery powered, only a 2 wire connection is required to operate the load. Electric heating loads up to 8A (1.6kW) can be switched directly, but please note that if more than 3A is being switched, the electric heat parameter EH should be set to value = 1 in the Installer Mode. This ensures the relay is operated with a higher energy, to switch higher currents reliably.

EN0H 8578 UK

INSTALLATION
Location DT90 is for use in normal domestic environments, and so should be located inside the house or building where the ambient temperature is within the range 0 to 40C. Avoid locations with high levels of condensing moisture. As the temperature control element in the heating/cooling system, DT90 MUST be located in a position with good air circulation at average room temperature on an inside wall 1.2 to 1.5m from the floor. Do NOT position the thermostat near sources of heat (radiators, hot air vents, TV or lights), near doors or window, or in direct sunlight.
Mounting DT90 can be mounted directly on the wall or onto an electrical wall box. The unit is supplied in 2 x halves, to enable quick and easy installation of the wiring backplate.
CAUTION isolate power supply and make safe before wiring the unit to prevent electric shock and equipment damage. Installation should be carried out by a qualified Electrician or competent Heating Engineer.
Wiring DT90 is for fixed wiring only and must be installed in accordance with the latest Electrical Regulations. Ensure the wiring connection to the supply is via a fuse rated at no more than 8 amps and a switch having contact separation of at least 3mm in all poles (formerly Class A).
Completing the Installation After wiring is complete, the front piece is attached to the backplate with a hinging action, until it clips into l

WIRING CONNECTIONS

a. b. c. d. e. f.
Boiler Boiler (potential free connection) Thermal actuator Zone valve Electric actuator Electric heat (maximum 1.6kW direct switching)

PRODUCT DIMENSIONS

INSTALLER MODE APPLICATIONS SETTINGS
The DT90 has a special Installer Mode where some features can be adjusted to suit the application and the needs or lifestyle of the user. Each adjustable feature is called a Parameter. These are described below. Parameter Minimum ON/OFF time Description and typical use DT90 is able to set a minimum limit for the on and off times of the controlled device or appliance, to prevent damage or excessive wear. This minimum time can be set to 1, 2, 3, 4, or 5 minutes, and is particularly important for heating applications with oil boilers, or air conditioning applications with compressors. Recommended settings are shown in the next table. Within the control proportional band, the output will be cycled several times per hour, to give precise temperature control. This can be set to 3, 6, 9, or 12 cycles, depending on the application. Recommended settings are shown in the next table. The proportional band is the temperature band, adjacent to the set temperature point, within which the thermostat will cycle the controlled output (to control the boiler, for example). Above or below this band the output will either be fully on or fully off. The band can be adjusted up to 3C (default 1.5C) to provide improved temperature control. This is useful for (a) well-insulated homes with over-sized heating systems or (b) air systems with a fast response If the thermostat is located in a particularly hot/cold location and cannot be moved because of the wiring, then the measured/displayed temperature can be adjusted by +/- 3C. This is useful if the homeowner wants the reading to match the temperature display on another appliance. The normal upper temperature limit of 35C can be reduced as low as 21C to save energy. The normal lower limit of 5C can be raised as high as 21C to protect inhabitants from the cold. On the DT90E ECO model, pressing the ECO button immediately puts the thermostat into energy saving mode, where it will control at this predefined temperature for as long as the user wishes. This temperature can be set from 5C to 35C. DT90 can be used for heating or cooling applications. If heating/cooling changeover is selected, the thermostat can be manually switched from heating to cooling (and back again) by pressing and holding the and buttons together for 3 seconds. When the off/standby button is activated, the DT90 will control to a special off/standby setpoint. By default this is set to 5C to provide frost protection, but it can be set up to 16C if required. It can also be set off, by setting the parameter value to -- to provide a positive off function. In cooling mode the default setting is off. If a direct electric heating application > 3A switching current is required, DT90 will use more energy to operate its relay and so ensure the higher current is switched reliably. This provides a means of resetting all the parameters to the factory supplied values.

Cycle rate Proportional band width
Temperature measurement offset Upper / Lower temperature limits Energy saving ECO temperature Heating or Cooling operation Off/standby setpoint
Electric heat operation Reset parameters
Some parameters require to be set to match specific applications. Recommended settings are shown in the table below. Specific Applications Setting Cycle Minimum s/ on/off time hour What requires to be changed?

Heating

Gas boilers (<30kW) Oil boiler Thermal actuator Zone valve
No changes required 1. Set minimum ON/OFF time to 4 minutes 2. Set cycle rate to 3 cycles/hour Set cycle rate to 12 cycles/hour No changes required 1. Configure the thermostat to allow switching between heating and cooling modes (set parameter HC = 1) 2. Set the thermostat to the required mode of operation (heating or cooling) by pressing the and buttons together for 3 seconds when in normal run mode (does not work in off/standby mode). 1. Set minimum ON/OFF time to 4 minutes 2. Set cycle rate to 3 cycles/hour

Air conditionin g

Heatpump / Air conditioner
INSTALLER MODE HOW TO SET PARAMETERS
Each parameter is identified by a 2-letter code, and has a range of values. These are shown in the table below, followed by instructions on how to enter Installer Mode, how to select a parameter and change its value, and finally how to exit Installer Mode. Description Minimum ON/OFF time Cycle rate Proportional band width Temperature measurement offset Upper setpoint limit Lower setpoint limit Energy saving ECO temperature (this parameter is only available on the DT90E model) Selection of heat/cool changeover Off/standby setpoint * Electric heat operation Parameter Ot Cr Pb tO uL LL ES HC OS EH Range of values 1, 2, 3, 4, 5 minutes 3, 6, 9, 12 cycles/hour 1.5 to 3.0C -3 to 3C 21 to 35C 5 to 21C 5 to 35C 0 = disable 1 = enable -- = off, 5 to 16C 0 if < 3A 1 if > 3A 0, 1 Factory (default) value 1 minute 6 1.5C 0 35C 5C 18C 0 5C (factory settings)
Reset parameters FS * In cooling mode the off/standby setpoint defaults to OFF To enter Installer Mode: a. Put DT90 into off/standby mode by pressing and holding the off/standby button for 2 seconds. b. Now press and hold both and temperature adjustment buttons for 3 seconds, until the display shows the word Inst. c. Press the button to get to the first parameter Ot. The parameter code is shown on the display separated by a colon from the parameter value.

Parameter Value

To select and change a parameter: d. Use the and buttons to move from one parameter to another. e. Press the off/standby button to select the parameter value, ready to change f. Use the and buttons to adjust the parameter value. When the correct value is flashing, confirm the selection by pressing the off/standby button again, returning to the parameter menu.

To exit Installer Mode: g. Press and hold the off/standby button for 3 seconds Note: Installer Mode will exit automatically after 10 minutes if no buttons are pressed.
INSTALLER MODE - FLOWCHART
ES parameter Only available on DT90E models
ENERGY EFFICIENCY AND THE ENVIRONMENT
Home energy use is currently responsible for more than of the total carbon emissions which contribute to climate change. Heating and hot water systems based on boilers account for 2/3 of this figure, so it is important to understand how controls can help to maximize energy efficiency while maintaining comfort. DT90 temperature controls should be used in conjunction with appropriate time controls. In order to save energy the following general points should be observed: 1. Ensure the system contains a room temperature thermostat and a hot water temperature thermostat (except for Combi boiler systems), and that both are set to appropriate temperature levels. 2. Programme the heating and hot water to be off when the house is not occupied. If possible frost damage to any exposed pipework is a concern, it is advisable to fit a frost protection thermostat or system. Honeywell can advise on this. 3. It is normal to have the heating system switched off, or set-back at night when heating is not required. 4. Think about how domestic hot water is used. In a storage system, it is not necessary to have this switched on all the time, even when the house is occupied. 5. Do not programme excessive heatup times for the central heating. If the occupier is out of the house, or still in bed, much of this heating would be unnecessary. 6. In the evening, when the house is up to temperature, it is often possible to switch the heating off up to an hour before going to bed, without any noticeable reduction in comfort.
The DT90 product family and its associated documentation and packaging are protected by various intellectual property rights belonging to Honeywell Inc and its subsidiaries and existing under the laws of the UK and other countries. These intellectual and property rights may include patent applications, registered designs, unregistered designs, registered trade marks, unregistered trade marks and copyrights. Honeywell reserves the right to modify this document, product and functionality without notice. This document replaces any previously issued instructions and is only applicable to the product(s) described. This product has been designed for applications as described within this document. For use outside of the scope as described herein, refer to Honeywell for guidance. Honeywell cannot be held responsible for misapplication of the product(s) described within this document. Manufactured in the UK, for, and on behalf of the Environment and Combustion Controls Division of Honeywell Technologies Srl, ACS-ECC EMEA, Z.A. La Pice 16, 1180 Rolle, Switzerland by its Authorised Representative Honeywell Inc.

Honeywell Control Systems Ltd. Newhouse Industrial Estate, Motherwell ML1 5SB, United Kingdom http://europe.hbc.honeywell.com

What is a room thermostat?
an explanation for householders
A room thermostat simply switches the heating system on and off as necessary. It works by sensing the air temperature, switching on the heating when the air temperature falls below the thermostat setting, and switching it off once this set temperature has been reached. Turning a room thermostat to a higher setting will not make the room heat up any faster. How quickly the room heats up depends on the design of the heating system, for example, the size of boiler and radiators. Neither does the setting affect how quickly the room cools down. Turning a room thermostat to a lower setting will result in the room being controlled at a lower temperature, and saves energy.

2 x LR6 AA Alkaline

1,2,3,4.,24hr 5s
The heating system will not work if a time switch or programmer has switched it off. The way to set and use your room thermostat is to find the lowest temperature setting that you are comfortable with, and then leave it alone to do its job. The best way to do this is to set the room thermostat to a low temperature say 18C and then turn it up by one degree each day until you are comfortable with the temperature. You wont have to adjust the thermostat further. Any adjustment above this setting will waste energy and cost you more money. If your heating system is a boiler with radiators, there will usually be only one room thermostat to control the whole house. But you can have different temperatures in individual rooms by installing thermostatic radiator valves (TRVs) on individual radiators. If you dont have TRVs, you should choose a temperature that is reasonable for the whole house. If you do have TRVs, you can choose a slightly higher setting to make sure that even the coldest room is comfortable, then prevent any overheating in other rooms by adjusting the TRVs.

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Switch ON/OFF (frost protection enabled) Botn de encendido / apagado (proteccin antihielo activada) Bouton Marche/Arrt (avec protection anti-gel) AAN/UIT-toets (vorstbeveiliging actief) Schalter Ein / Aus (Frostschutz aktivieren) Interruttore ON / OFF (protezione antigelo abilitata) KI/BE kapcsol (fagyvdelem aktivizlsa) Spna Zapnuto/Vypnuto (aktivovan protimrazov ochrana) Wcz/Wycz (aktywna ochrona przeciwzamarzaniowa) Spna Zapnut/Vypnut (aktivovan protimrazov ochrana) 1

Low battery indicator Indicador de pilas agotadas Indication dusure de piles Symbool voor batterijvervanging Anzeige fr Batteriewechsel Indicazione cambio delle batterie Kimerlt elem jelzs Indikace vybit baterie Wskanik wyadowania baterii Indikcia vybitch batrii
Room thermostats need a free flow of air to sense the temperature, so they must not be covered by curtains or blocked by furniture. Nearby electric fires, televisions, wall or table lamps may prevent the thermostat from working properly.
This product and its associated documentation and packaging are protected by various intellectual property rights belonging to Honeywell Inc and its subsidiaries and existing under the laws of the UK and other countries. These intellectual and property rights may include patent applications, registered designs, unregistered designs, registered trade marks, unregistered trade marks and copyrights. Honeywell reserves the right to modify this document, product and functionality without notice. This document replaces any previously issued instructions and is only applicable to the product(s) described. This product has been designed for applications as described within this document. For use outside of the scope as described herein, refer to Honeywell for guidance. Honeywell cannot be held responsible for misapplication of the product(s) described within this document. Manufactured for and on behalf of the Environment and Combustion Controls Division of Honeywell Technologies Srl, ACS-ECC EMEA, Z.A. La Pice 16, 1180 Rolle, Switzerland, by its Authorised Representative Honeywell Inc.
http://europe.hbc.honeywell.com 2008 Honeywell International Inc.

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Installation / Instalacin / Installasion / Installatie / Installazione / Telepts / Mont / Instalacja / Intalcia 1 2

= M3.5 = No6

Display Pantalla Affichage LCD scherm LCD-Anzeige
Display Kijelz Displej Wywietlacz Displej
Parameter Parmetro Paramtre Parameter Parameter Parametro Paramter Parametr Parametr Parameter
Value Valore Valeur Waarde Wert Valori rtk Hodnota Warto Hodnota
Parameters / Parmetros / Paramtres / Parameters / Parameter / Parametri / Paramterek / Parametry / Parametry / Parametre
Description Descripcin Description Omschrijving Beschreibung Descrizione Lers Popis Opis parametru Popis Minimum ON/OFF time / Tiempo mnimo de marcha / Dure minimale de marche/arrt / Minimale aan/uit tijd / Minimale Einschaltzeit Ein/Aus / Tempo minimo accesso/spento / Minimum BE/KI id / Minimln doba sepnut / Minimalny czas zaczenia kota / Minimlna doba zopnutia Cycle rate / Frecuencia de los ciclos / Nombre de cycles/heure / Aantal schakelingen per uur / Zykluszeit / Frequenza dei cicli / Ciklusid / Poet cykl / Czstotliwo cykli / Poet cyklov Proportional band width / Amplitud de banda proporcional / Bande proportionnelle / Proportionele bandbreedte / Proportionalband / Larghezza della banda proporzionale / Arnyos sv szlessg / ka psma proporcionality / Szeroko pasma proporcjonalnego / rka psma proporcionality Temperature measurement offset / Desviacin permanente de la temperatura / Etalonnage de la sonde / Temperatuurcompensatie / Temperatur-Offset / Compensazione della temperatura / Hmrsklet mrs eltols / Korekce namen teploty / Kompensacja temperatury / Korekcia nameranej hodnoty Upper setpoint limit / Lmite superior de temperatura / Temprature limite de consigne maximale / Max. temp. instelling / Obere Temperatursollwertgrenze / Limite superiore della temperatura / Fels alapjel korlt / Nejvy nastaviteln teplota / Grny limit temperatury / Najvyia nastaviten teplota Parameter Parmetro Paramtre Parameter Parameter Parametro Paramter Parametr Parametr Parameter Ot Range of values Rango de ajuste Plage de rglage Instelmogelijkheden zustzliche Einstellungen Campo di modifica rtk tartomny Rozsah hodnot Zakres wartoci Rozsah hodnt 1,2,3,4,5 m Default Predefiniti Valeur dusine Fabrieksinstelling Werkseinstellungen Predefiniti Alapbellts Pednastaven hodnoty Ustawienie fabryczne Prednastaven hodnoty 1m