504 High
Your boiler has lost its flame during operation, meaning it can no longer heat your water or home safely.
Technical description: All Boilers
Typical repair cost: £100-£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 504 — no call-out fees, no surprises.
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Parts commonly replaced
- Ionisation probe
- Gas valve
- Ignition electrode
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