BoilerFaultCodesYour boiler's control panel and the internal computer are having trouble communicating with each other, meaning the display may not work or respond to your commands.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: User interface fault
What causes this fault?
This fault occurs when the data link between the display panel you interact with and the main computer inside the boiler is broken. The most common reason is an electronic component failure on one of the circuit boards or a loose connection in the internal wiring harness.
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 F18 — 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.