BoilerFaultCodesTechnical description
Ionisation current
What causes this fault?
This fault occurs when the boiler's internal sensor can no longer detect a steady flame while the burner is active, leading the system to shut down for safety. The most common reasons are a worn-out sensing probe that can't 'see' the fire, a blockage in the gas supply, or an incorrect mixture of gas and air preventing a stable burn.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register →