Imagine a room thermostat

...with a slim, modern design.
...that’s designed for compatibility
...and supports greener energy systems.

The Honeywell Home DT4 Room Thermostats: Where functionality meets elegance

eye-pleasing design icon

Designed for installers. Made for users.

DT4 Room Thermostats combine slim, modern design with simple functionality. They’re designed to be easy to use, with features that are easy to love.

heat pump icon

Designed for compatibility.

DT4 Room Thermostats are designed to work with on/off and OpenTherm® compatible heating and cooling appliances, such as boilers, heat pumps and district heating systems. Featuring both wired and wireless versions, they're designed to suit a variety of homes, and for a multitude of system applications.

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Supporting greener energy systems.

DT4 Room Thermostats can be installed as a standalone thermostat or part of a wider home comfort solution with products such as the HCC100 underfloor multi-zone controller. DT4 Room Thermostats are compatible with a range of hybrid and greener energy systems and energy-efficient solutions.

Parent reading a book with a child.

The only thermostat you need

As the first point of contact for homeowners, installers know exactly what features household appliances should have. That’s why we listened to feedback from professionals when developing the DT4 Room Thermostats, to ensure they deliver everything you and your customers need – just like you imagined.

The DT4 range

Product comparison Table



DT40WT20 (white)
DT40GT21 (grey)
DT40BT22 (black)
YT42WRFT20 (white)
YT42GRFT21 (grey)
YT42BRFT22 (black)
DTS42WRFST20 (white)
DTS42GRFST21 (grey)
DTS42BRFST22 (black)


White, Grey, Black White, Grey, Black White, Grey, Black


yes yes yes


YES (included) YES (included) YES (included)


3.5 years 1.5 years 1.5 years


BDR91A evohome, ST9000 Timer range, HCC100, BDR91A, HCE80, HCC80


Boilers, heat pumps, zone valves, underfloor controls, solid fuel boiler, electric heater Boilers, heat pumps, zone valves, underfloor controls, solid fuel boiler, electric heater, replacement market Zoning, underfloor controls, replacement market


5 years 5 years 5 years
*Resideo survey of 90 installers and 326 VOC’s feedback 2022.
**Battery life estimated on 10 interactions a day for 5 seconds per interaction.
***Compatibility with common appliances that support OpenTherm® or on/off control. Compatibility with heat pumps based on commonly used heat pump performance profiles in 2023.
****See terms at

The DT4 range brochure

Discover more about the full DT4 range of thermostats.

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Get the right training for the right job.

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