Thermostat shows E14 and heating output is locked out

Safety first: Turn off power at the breaker before inspecting wiring or load.

Steps to troubleshoot E14 (safety lockout):

• 1. Power cycle and clear error:
  • Turn off power for 5 minutes.
  • Restore power and see if E14 clears automatically.
• 2. Check load size and wiring:
  • Verify the connected heating load does not exceed the thermostat's rated current.
  • Inspect wiring for shorts, loose connections, or signs of overheating at the terminals.
• 3. Review event history (if supported):
  • Use the Fibaro controller to check device logs for overcurrent or overtemperature events.
• 4. Factory reset:
  • Perform a factory reset to clear stored fault states.
  • Reconfigure the thermostat and test operation.
• 5. Replace thermostat if lockout persists:
  • Persistent E14 after verifying load and wiring suggests an internal hardware or firmware integrity issue; replace the unit.

When to call a professional: If you find any signs of overheating or melted insulation, stop using the system and call an electrician immediately.