Display shows E5 and thermostat does not respond to temperature changes

Safety first: You can perform configuration changes with power on, but do not touch live terminals. If you need to open the thermostat, turn OFF power at the breaker.

Steps to troubleshoot:

• 1. Verify sensor type setting:
  • Enter the installer menu on your Heatit thermostat (refer to model-specific manual).
  • Locate the sensor type parameter (e.g. NTC 10k, NTC 12k, external sensor).
  • Set it to match the installed sensor (most Heatit floor sensors are NTC 10k).
• 2. Check temperature limits:
  • Verify that minimum and maximum floor/room temperature limits are set within a normal range (e.g. 5–40°C).
  • Reset to default values if unsure.
• 3. Factory reset:
  • Perform a factory reset to clear any corrupted calibration data.
  • Reconfigure only essential parameters and test operation.
• 4. Firmware update (if supported):
  • For Z-Wave models like Heatit Z-TRM3, check if a newer firmware is available via your Z-Wave gateway.
  • Update firmware following the gateway's OTA procedure.
• 5. Replace thermostat if error persists:
  • If E5 remains after correct configuration and reset, the internal measurement circuit is likely defective.
  • Replace the thermostat with a new compatible Heatit model.