Technical description
Regulation current value has been reached. Try resetting the boiler, check the gas pressure and check the combustion values and CO2 calibration – if this doesn’t work the board or valve needs replacing.
What causes this fault?
This fault occurs when the boiler's control system can no longer accurately monitor or adjust the flame to ensure safe burning. It usually means the electronic signals between the gas valve and the main control board have drifted outside of safe limits, often due to a failing component or poor gas flow. As a result, the boiler shuts down because it cannot guarantee the fuel is burning efficiently or safely.
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.