This is a sensor problem, here are a few fixes:
- Check to ensure the thermostat is firmly connected to the “C” and “D” ports behind the face plate of the thermostat.
- If you did not install a floor sensor or it is damaged, set the thermostat to red ambient temperature:
- Press the OK button twice to bring up the main menu.
- Use the UP or DOWN buttons to scroll to SETTINGS, then press OK.
- Use the UP or DOWN buttons to scroll to APPLICATION, then press OK.
- Use the UP or DOWN buttons to select ROOM, then press OK.
- Set desired temperature (some model of thermostat)
- Use the UP or DOWN buttons to scroll to EXIT, then press OK. (do this twice)
- Your thermostat will now measure the temperature of the room and NOT the floor sensor. (TIP: You may have to adjust the thermostat temperature higher or lower than expected to achieve desired floor temperature.)
- Test the floor sensor to measure resistance to check for resistance.
- Set your multimeter to the 200k Ohm (Ω) setting.
- touch a probe to each end of the sensor wire.
- A functioning floor sensor should get a reading between 9,000 and 25,000 ohms, if the sensor fails this test, please see #2 for how to switch to ambient air sensor.
NOTE: Whenever working on ANY wiring for the thermostat, please TURN OFF the breaker powering the thermostat and floor heating system.