356 High
Your boiler is not receiving enough electrical power from the main supply to operate safely and has shut down as a precaution.
Technical description: Low mains voltage – the voltage may be interrupted or inconsistent and needs checking
Typical repair cost: £100-350 (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 356 — no call-out fees, no surprises.
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Parts commonly replaced
- Printed Circuit Board (PCB)
- External Voltage Regulator
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