Frequently asked questions

• The incoming and outgoing (switched) phases are reversed. As a result, the return resistor is constantly energized and acts to lower the temperature in the room. In addition, the temperature fluctuation is very large (approx. 5–8 K).
• The heating capacity is insufficient for the room. As a result, the controller is active for too long, causing the feedback resistor to remain on for an extended period and effectively lowering the room temperature.
• External heat sources affect the thermostat (e.g., the sun, a TV, a lamp, etc.). These external heat sources cause the thermostat to register a higher temperature than is actually present, resulting in the room not being heated sufficiently.

• The thermostat is mounted, for example, behind a curtain, on an exterior wall, or next to a door. The thermostat is tricked into thinking the room is cooler than it actually is, causing the room to overheat.

• Actuator defective; actuator does not open the valve.
• There may be coarse construction debris inside the switch. This debris prevents the contacts from closing.
• The thermostats for the two rooms are connected in series. These rooms will only heat up if both thermostat contacts are closed.

Additional information:

• It is particularly important to note that underfloor heating has very long response times. The room heats up very slowly and also cools down very slowly (sunlight, for example, can cause overheating). Therefore, you cannot expect a cooled-down room to reach the desired room temperature immediately after turning up the control knob on the thermostat.
• In well-insulated rooms, it is also important to note that the room temperature drops very slowly. As a result, even with the “night mode” setting (e.g., 4°C lower), the room temperature may drop only slightly at night, meaning the heating system may not activate for an extended period.
• Very often, the operation of bimetallic regulators is impaired or completely disabled by construction debris that has gotten inside. Therefore, always install the regulators only after any necessary filling, painting, or wallpapering work has been completed. Be sure to avoid drill dust.

• The neutral conductor N is not connected to terminal 4 of the controller.
• Although the neutral conductor N is connected to terminal 4 of the controller, it is not connected in the distribution panel (junction box, fuse box).