BoilerFaultCodesYour boiler is failing to light the small test flame needed to start the main burner, meaning your heating and hot water will not work.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: - no flame (signal) of pilot burner - no spark
What causes this fault?
This fault occurs when the boiler's control system attempts to start the heating process but cannot detect the small pilot flame required to safely ignite the main burner. It is typically caused by a worn-out ignition spark plug, a blocked pilot gas injector, or a failure in the electronic transformer that generates the spark.
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 end of yellow zone; begin of red zone — 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.