Wireless switching centre Termojet (8 zones, 16 actuators) TJ03RFWS

Termojet TJ-03-RF is a local wireless switching hub for zone control of hydronic heating. It receives radio signals from up to 8 wireless thermostats of the WT-150 series at 868 MHz and controls up to 16 thermoelectric actuators M30×1.5 in underfloor manifolds. It simultaneously sends signals to the boiler (potential-free “dry contact”) and the circulation pump — activating them only when at least one zone requests heat. Wall or DIN-rail mounting. No cable from room thermostats is required — 868 MHz wireless communication provides a stable connection up to 120 m in open space.

Technical Specifications

Operating Principle

Each WT-150 series thermostat is paired with a specific channel (zone 1–8) of the TJ-03-RF hub. When the room temperature drops below the set point, the thermostat sends a radio signal to the hub. The hub opens the thermoelectric actuator of the corresponding circuit — the heat carrier flows to the underfloor or radiator of that zone. As soon as at least one actuator is open, the hub activates the boiler and pump through the respective outputs. When all zones are satisfied — the boiler and pump switch off automatically.

The actuator type (NO — normally open, NC — normally closed) is selected by jumper switches on the board. The shutdown delay of the boiler and pump after the last actuator closes is also set by a jumper switch (0–6 min) — this allows the boiler to “pump out” the remaining heat into the system.

Applications

• Hydronic underfloor heating with multiple rooms. Each room has its own zone and its own WT-150 thermostat. The bedroom floor is warmer at night, the living room during the day, the children’s room on a separate schedule. All control is local, with no internet dependency.
• Renovation without running cables from thermostats. TJ-03-RF receives the wireless signal from WT-150: no need to chase walls to run a wire from each room to the manifold cabinet.
• Combined systems (underfloor + radiators). Some zones control underfloor circuits, others control radiator branches. The hub processes all requests simultaneously and activates the boiler only when there is real demand.
• House with up to 8 rooms. 8 independent zones cover a standard private house or a small commercial facility: office, clinic, shop.
• Boiler and pump optimisation. Thanks to the “heat request” function, the boiler and pump do not run continuously — they activate only when at least one zone actually needs heat, reducing energy consumption.

Advantages of Termojet TJ-03-RF

• Wireless thermostats — no cables from rooms to the manifold cabinet, installation in any house without renovation.
• 8 independent zones and up to 16 actuators — flexible configuration for houses of any layout.
• Automatic boiler and pump control — “smart” logic saves energy and extends equipment service life.
• Jumper configuration of actuator type and delay — adaptation to any scheme without additional programming.
• DIN-rail or wall mounting — convenient in any manifold cabinet.
• Fully local control — the system operates without internet or cloud services: 24/7 reliability.

TJ-03-RF and Heat Pump

Heat pumps operate most efficiently at low heat carrier temperature — exactly the mode that hydronic underfloor heating provides. TJ-03-RF activates the heat pump only when there is real demand from the heating zones, allowing it to run in long, steady cycles — this increases COP and reduces compressor wear. The potential-free “dry contact” boiler output is compatible with the standard control input of any heat pump. For more about integrated solutions — visit the Termojet heat pump website.

Frequently Asked Questions

Which thermostats are compatible with TJ-03-RF?
TJ-03-RF is designed to work with wireless thermostats of the WT-150 thermostat series at 868 MHz. Pairing a thermostat with the required channel is performed via buttons on the switching hub — the procedure is described in the manual and takes less than a minute per zone.

Does TJ-03-RF connect to an app or Wi-Fi?
No. TJ-03-RF is a local switching hub without built-in Wi-Fi: it receives commands exclusively from WT-150 wireless thermostats via the 868 MHz radio channel and controls actuators and the boiler locally. This is an advantage, not a limitation — the system is fully autonomous and does not depend on the internet connection or cloud services. If you need zone control via smartphone or smart home integration — refer to our solutions catalogue or see Termojet Zone Control — Catalogue. Also note the Wired Hub TJ-03-C for wired thermostats. Thermoelectric actuators M30×1.5 are connected to each zone.