F.20 High
Your boiler has switched itself off because it has become too hot internally and needs to cool down for safety.
Technical description: Safety switch-off – overheating temperature reached
Typical repair cost: £100-£350 (including labour)
DIY fix possible
Check that your radiator valves are open and not turned to the off positionEnsure your boiler pressure is between 1.0 and 1.5 bar on the displayPress the reset button (a flame symbol with a cross through it) once the boiler has cooled down
Protect yourself from future repair bills
A boiler cover plan would cover faults like F.20 — no call-out fees, no surprises.
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Parts commonly replaced
- Circulation pump
- Overheat thermostat
- Main heat exchanger (flushing)
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