BoilerFaultCodesYour boiler is unable to light the gas burner because a safety control valve inside the unit has stopped working.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Honeywell Control solenoid valve failed.
What causes this fault?
This fault occurs when the main gas control valve fails to open, preventing fuel from reaching the burner to create a flame. The most common reason is that the internal electrical coil has burnt out or the mechanical valve has become stuck due to age and wear. This acts as a safety shutdown to ensure gas does not flow when it cannot be safely ignited.
This failure is more frequent during the first cold snap of autumn, as the internal components can seize up after being inactive throughout the summer months.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like C(3) — no call-out fees, no surprises.
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Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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