BoilerFaultCodesYour boiler has lost power internally because a small fuse has blown, meaning the system cannot run its basic safety checks or start up.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fuse (F1A) on Printed Circuit Board
What causes this fault?
This fault occurs when a surge of electricity or an internal component failure causes a safety fuse on the main control board to blow. The most common reason is an aging component like the pump or fan drawing too much power, which acts as a safeguard to prevent further damage to the electronics. Once this fuse goes, the boiler loses its 'brain' and cannot perform any operations until the electrical circuit is restored.
This fault is slightly more common in winter when the pump and fan are working at their highest intensity for long periods, putting more strain on the electrical circuit.
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 F2 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm Ultimate 30ff is discontinued — time for a new one?
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.
Affiliate links — we may earn a commission at no extra cost to you.