BoilerFaultCodesYour boiler has tried to light the gas but failed, meaning it cannot provide heating or hot water until reset.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Ignition unsuccessful when starting up
What causes this fault?
This fault occurs when the boiler attempts to ignite the gas three times but fails to detect a flame. The most common reasons are a temporary interruption in your gas supply, a blocked burner, or an issue with the electrodes that create the spark needed for ignition.
This fault is more frequent during extreme cold spells, as external gas meters or pipes can sometimes freeze or experience pressure drops.
DIY fix possible
Check that your gas meter has credit and the isolation valve is openPress the Reset button (the flame symbol with a cross) for one secondCheck if other gas appliances in your home, like a hob, are working correctly
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 F.28 — 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.