Thermostat shows 'FLOOR LO' or similar and may prevent heating from starting in floor-protection mode.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety first: Turn off power to the underfloor heating system before accessing wiring.
Steps to check:
- Check sensor wiring: Ensure the floor sensor is firmly connected to the correct terminals on the Salus thermostat and that no joints are loose or corroded.
- Measure resistance: With power off, measure the sensor resistance. If it is extremely high (beyond the NTC curve) or open circuit, the sensor or cable is faulty.
- Review installation: Confirm that the sensor is actually installed in the heated area and not left coiled in a cold void or outside the heated zone.
- Replace sensor if needed: Fit a new, compatible Salus floor sensor and route it in a conduit so it can be replaced in future if necessary.
Resolution: After fitting a correct sensor and verifying wiring, clear any alarms by power-cycling the thermostat. If 'FLOOR LO' persists with a good sensor, replace the thermostat.
Repair Difficulty
Required Part
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