How to Fix / Troubleshooting

Safety first: Isolate power and gas. Do not operate the heater with a suspected flue fault; risk of carbon monoxide exposure.

Check flue externally: Inspect the flue terminal for obstructions and ensure clearances meet Certikin installation requirements.
Ventilation: Confirm that the plant room has adequate ventilation openings and that they are not blocked.
Inspect flue sensor: Locate the flue temperature sensor on the flue hood and check that it is securely mounted and wired.
Visual heat exchanger check: Look for signs of heavy soot or discoloration around the burner and heat exchanger.
Do not reset repeatedly: If E6 recurs, stop using the heater until inspected by a gas-safe engineer.

Flue and combustion issues must be addressed professionally to ensure safe operation.

E6 error; heater may lock out after a short run period.

Possible Causes