BoilerFaultCodesYour boiler has switched itself off for safety reasons because a internal component or the system itself is not operating correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: The safety devices have been activated (lockout)
What causes this fault?
This fault occurs when the boiler’s safety sensors detect an internal error that requires the system to shut down to prevent damage. It is typically triggered by a failure in the electronic control board or a vital component like the pump failing to move water correctly. In some cases, it can also be caused by an issue with the ignition process failing to safely light the burner.
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 E05 — 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.