BoilerFaultCodesThe 6 most common faults
Your boiler has automatically shut itself down because it became too hot, acting as a safety measure to prevent damage.
Why it happens: This fault occurs when the water inside the heat exchanger reaches a dangerously high temperature, triggering a safety switch to cut the power. The most common reasons are a failed pump that isn't moving water around the system quickly enough or a blockage in the pipework caused by a build-up of sludge. It can also happen if the external controls fail to tell the boiler to turn off once the house is warm.
Wait for the boiler to cool down completely (at least 30 minutes).Locate the reset button, usually found under the front of the boiler casing.Press the button firmly to reset the thermostat; the boiler should then attempt to relight.
Your boiler has detected a faulty component that usually helps cool the system down after it finishes running, meaning it may stop working to prevent overheating.
Full guide for Pump overrun thermostat faultYour boiler is struggling to start up correctly because the internal mechanism that pushes air through the system is failing to engage.
Full guide for Fan does not runYour boiler's fan is running as normal, but the system is failing to ignite the gas required to produce heat.
Full guide for Fan operates / No sparkYour boiler is failing to start because the small pilot flame that triggers the main burner cannot ignite.
Full guide for Pilot does not lightYour boiler is failing to ignite because it cannot create the necessary spark to light the burner.
Full guide for No spark at electrodeon the Potterton Profile 30E
Based on parts cited in our fault code database. Your engineer will confirm what's actually needed after diagnosis.
Call a Gas Safe engineer if…
- You can smell gas or see signs of a leak
- The Potterton shows an Emergency or High severity code
- The boiler keeps locking out after repeated resets
- You've tried the DIY checks and the fault hasn't cleared
- There's visible water leaking from the boiler
- The flame is yellow or orange instead of blue