F4 High
Your boiler is failing to stay lit or cannot start the flame required to provide heating and hot water.
Technical description: Ignition fault (lockout) Went out when lit
Typical repair cost: £120-350 (including labour)
DIY fix possible
Check if other gas appliances (like a hob) are working to ensure gas is reaching the propertyEnsure your pre-paid gas meter has credit, if applicablePress the Reset button (indicated by a flame with a cross through it) for five seconds
Protect yourself from future repair bills
A boiler cover plan would cover faults like F4 — no call-out fees, no surprises.
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Parts commonly replaced
- Ignition electrode
- Flame sensing electrode
- Gas valve
- Printed Circuit Board (PCB)
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