20 High
Your boiler is struggling to detect the flame needed to heat your water, even if the burner has successfully lit.
Technical description: Flame sensing fault
Typical repair cost: £90-250 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Protect yourself from future repair bills
A boiler cover plan would cover faults like 20 — no call-out fees, no surprises.
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Parts commonly replaced
- Ionisation probe
- Ignition electrode
- Printed Circuit Board (PCB)
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