BoilerFaultCodesYour boiler's internal computer has encountered a critical electronic glitch that is preventing it from running safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Internal error
What causes this fault?
This fault occurs when the boiler's central control board suffers a critical electronic failure, meaning it can no longer communicate with the internal components. The most common reason is a hardware malfunction within the circuitry or an electrical surge that has damaged the delicate microprocessors. In some cases, loose or damaged wiring connections between the board and the sensors can also trigger this shutdown.
DIY fix possible
Locate the 'Reset' button on the front control panelPress and hold the button for 5 seconds, then releaseWait up to 10 minutes to see if the boiler restarts and the error clears
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 F0 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
Affiliate links — we may earn a commission at no extra cost to you.