Display shows Er2 and thermostat shows unrealistic floor temperatures

Safety first: Turn OFF power at the breaker before working on wiring.

Steps to troubleshoot:

• 1. Compare displayed temperature with reality:
  • Use an infrared thermometer or contact thermometer on the floor surface.
  • If the reading differs by more than 5–10°C, suspect sensor or configuration.
• 2. Verify sensor type in menu:
  • Ensure the thermostat is set to the correct NTC value (commonly 10k for Heatit sensors).
• 3. Measure sensor resistance:
  • Disconnect the sensor and measure resistance at room temperature.
  • Compare with the sensor's resistance table from the manual.
  • If resistance is far outside expected range, replace the sensor.
• 4. Check sensor placement (if accessible):
  • If the sensor is in a conduit, gently pull it out and verify it is not touching the heating cable directly.
  • Reposition it centrally between heating runs.
• 5. Replace sensor if damaged:
  • Install a new Heatit NTC floor sensor and route correctly.