Ideal boiler displays C0, boiler may appear to run pump without firing

Information: C0 on many Ideal models indicates a normal operating mode where the pump runs briefly after the burner stops to dissipate heat or prevent pump seizure.

User guidance:

• Allow the boiler to complete its cycle; the code should clear automatically.
• If the boiler remains on C0 for an extended period with no heating or hot water, check that the room thermostat is calling for heat and that timers are set correctly.

If you suspect a fault (e.g. no heating despite demand), contact a heating engineer to check pump and control operation.