BoilerFaultCodesYour boiler's electronic brains have encountered an internal software or communication error and can no longer control the heating safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Internal control error
What causes this fault?
This fault occurs when the boiler's internal computer chips fail to talk to each other correctly or lose programmed data. It is usually caused by a physical hardware failure within the main control board or a sudden electrical surge that has corrupted the system's memory.
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 E29 — 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.