Display shows E1 and thermostat stops heating the floor or room

Safety first: Turn OFF power to the thermostat at the circuit breaker before removing it from the wall box. Verify power is off with a non-contact voltage tester.

Steps to troubleshoot:

• 1. Check sensor wiring at the thermostat:
  • Remove the Heatit thermostat front from the wall (follow the manual for your specific model, e.g. Heatit Z-TRM3, Heatit Z-TRM2fx).
  • Locate the NTC floor sensor terminals (often marked "NTC" or with sensor symbol).
  • Ensure both sensor wires are firmly clamped and not broken or corroded.
• 2. Measure sensor resistance:
  • Disconnect the sensor wires from the NTC terminals.
  • Use a multimeter set to kΩ range and measure across the two sensor wires.
  • A typical Heatit NTC 10k sensor should read around 10 kΩ at 25°C (higher resistance when colder, lower when warmer). If the meter shows OL (open) or extremely high resistance, the sensor is open.
• 3. Inspect for cable damage:
  • If accessible, inspect the sensor cable from the thermostat to the floor entry point for cuts, staples, or crushed sections.
  • If the cable is damaged in the wall or floor, the sensor must be replaced and a new cable routed.
• 4. Replace the floor sensor if faulty:
  • Purchase a compatible Heatit NTC floor sensor (10k) or the exact type specified in your model manual.
  • Route the new sensor in a conduit if possible, from the thermostat box to the floor area.
  • Connect the two sensor leads to the NTC terminals, tighten screws, and reassemble the thermostat.
• 5. Reset error:
  • Restore power at the breaker.
  • The E1 error should clear automatically once a valid sensor is detected. If not, perform a factory reset according to the user manual.