Wired programmer in flush-mount box Termojet HT-120 HT120WHT (white)

Termojet HT-120 — a wired Wi-Fi thermostat for hydronic underfloor heating for installation in a standard back box (depth from 35 mm). The built-in 2.4 GHz Wi-Fi allows you to control the heating via the Smart Life app from a smartphone anywhere in the world. Housing colour — white.

Technical Specifications

How It Works

HT-120 measures temperature in three selectable ways: by room air (built-in sensor), by floor temperature (external sensor NTC10K, 2 m cable), or both simultaneously — the floor heats up to the set limit while the room temperature controls the final comfort level. The floor overheat limit is adjustable in the range of 20–80°C, protecting laminate or parquet from damage.

When connected to the switching centre TJ-03-C, the thermostat becomes part of an 8-zone system: each room has its own schedule and its own temperature. The switching centre opens the appropriate actuator and activates the boiler and pump only when there is an actual heat demand from the zone.

Use Cases

• New build or major renovation. Installation in a back box in any standard mounting box — the thermostat takes the place of a regular socket or switch.
• Room zoning. Paired with TJ-03-C and thermostatic actuators — up to 8 independent underfloor heating zones with an individual schedule for each room.
• Phone control. Weekly programming with 4 temperature levels for each day, Eco and holiday mode — all configured via Smart Life from anywhere.
• Voice control. "OK Google, raise the temperature in the bedroom" — integration with Google Home and Amazon Alexa without additional hubs.

Advantages of HT-120

• Wi-Fi without a hub — the built-in 2.4 GHz module connects directly to the home router.
• Two sensor modes — air only, floor only, or a combination for maximum comfort.
• Floor overheat protection — the 20–80°C limit protects wooden floors and laminate.
• Open window detection — automatic pause when temperature drops sharply.
• Also available in black HT-120 BLK for dark interiors.

HT-120 and Heat Pump

A heat pump is most efficient with low-temperature underfloor heating and zone control. HT-120 allows precise maintenance of the supply temperature in each zone, reducing unnecessary start/stop cycles and increasing the system COP. Learn more about heat pumps at tjheatpump.com.ua.

Frequently Asked Questions

Is the NTC10K sensor included with HT-120?
HT-120 has a built-in air sensor and can operate without an external sensor. However, for underfloor heating, the NTC10K sensor is recommended: it is laid in conduit under the floor and provides accurate screed temperature measurement — exactly what is needed to protect the floor covering.

How do I connect HT-120 to the switching centre?
HT-120 connects by wire to the corresponding thermostat input of the switching centre TJ-03-C. The centre receives the heat demand signal and independently opens the required actuator, starts the pump and boiler. The full zone control catalogue is in the Termojet section.