How to Fix / Troubleshooting

Safety first: Allow the boiler to cool completely before attempting a reset. Surfaces and water may be extremely hot.

Check system pressure and valves: Ensure adequate pressure and that all isolation valves are open.
Bleed air and check pump: Remove air from the system and confirm the Nibe pump is running when there is a demand.
Locate reset button: Some Nibe boilers have a manual reset button on the safety thermostat behind the front cover. Press gently once to reset after cooling.
Do not repeatedly reset: Repeated trips indicate a serious underlying issue such as a blocked heat exchanger. Call a technician.
Professional descaling: In hard water areas, a Nibe technician may need to chemically descale or replace the primary heat exchanger.

Boiler shows internal overheat or safety thermostat trip, complete lockout

Possible Causes