BoilerFaultCodesYour boiler's internal computer brain is having trouble processing information and has temporarily stopped working.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: RAM error
What causes this fault?
This fault occurs when the boiler's main control board experiences a memory failure, preventing it from storing or reading vital operational data. It is typically caused by a hardware malfunction within the circuitry or an electrical surge that has corrupted the board's internal processors.
DIY fix possible
Locate the power switch or dial on the boiler.Turn the boiler off and wait for 60 seconds.Turn the boiler back on to see if the internal memory resets itself.
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 A09 — 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.