BoilerFaultCodesYour boiler is stuck in its starting sequence because it cannot confirm the fan is working correctly to clear away waste gases.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Fan on
What causes this fault?
This fault occurs when the boiler's internal computer signals the fan to start, but fails to receive confirmation that air is moving through the system to safely clear waste gases. It is usually caused by a mechanical failure of the fan motor, a blockage in the flue, or a faulty sensor failing to detect the airflow.
This issue is slightly more common in autumn and winter, as debris like fallen leaves or nesting material can block the external flue pipe, preventing the required airflow.
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 LED3 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Ideal Minimiser FF 30 80 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.