The new family of non-programmable thermostats is born!
The DT90 is the new comer in the Honeywell family of thermostats. This slim line non-programmable thermostat has been designed by Honeywell for controlling a wide range of applications including hydronic heating conventional and combi boiler system, zoning with hydronic system, underfloor heating system, electric heating system and fancoil units. It does not only replace the DT200 but also stands out from the competition by providing some of the most advanced features you can possibly find in a product for this market segment.

Some of the features of the DT90 are:

Self-learning fuzzy logic control: DT90 uses a self-learning ‘fuzzy logic’ time-proportional control algorithm. This form of control offers more flexibility compares to a conventional PI control. 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.
ECO (energy savings) button: 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 user’s choice. The ECO energy saving setpoint is pre-defined in the Installer Mode. The factory setting is 18°C, but it can be adjusted (between 5°C and 35°C) 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.

Very large LCD 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 labelled ? 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 0.5°C.

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.

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.

Part Number:  DT90A1008 (Standard version)

Part Number:  DT90E1012 (ECO version)