BoilerFaultCodesYour boiler's main control panel has lost communication with the internal system, meaning your settings or commands aren't being processed correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Local user interface fault
What causes this fault?
This fault occurs when the digital connection between the boiler's display screen and the main internal brain is broken. The most common reason is a loose or damaged wiring connection between the two components, though it can also be caused by an electrical failure on one of the circuit boards themselves.
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 18 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Glow-worm 30ci 30si 35ci 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.