BoilerFaultCodesThe 6 most common faults
Your boiler has tried to light but failed, meaning it cannot currently provide any heating or hot water.
Why it happens: This fault occurs when the boiler's control system attempts to ignite the burner but fails to detect a steady flame after several attempts. The most common reasons include a lack of gas reaching the unit, worn-out ignition sparks, or a dirty sensor that can no longer 'see' the flame even if it has lit.
Check if your gas supply is active (e.g., check other gas appliances like a hob)If you have a prepaid meter, ensure you have credit and the valve is openPress and hold the reset button for at least 5 seconds
Your boiler has safety-tripped because it has detected an overheating issue within the internal system.
Why it happens: This fault occurs when the internal water temperature exceeds a safe limit, causing the overheat thermostat to shut the system down to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage within the main heat exchanger that restricts flow. It can also be triggered by trapped air in the pipework or a faulty sensor providing an incorrect temperature reading.
Check that your home's radiator valves are fully open.Ensure there is enough water pressure in the system (typically between 1 and 1.5 bar).Turn the control knob to the 'Reset' position, hold for five seconds, and release.
Your boiler has stopped working because it either cannot detect a flame to heat the water or the internal drainage pipe for waste water is blocked.
Why it happens: This fault happens when the boiler attempts to light but fails to detect a stable flame, often because the electrodes are worn or the gas supply is restricted. It can also be triggered if the internal waste water pipe becomes backed up with debris or liquid, which prevents the combustion process from starting safely. In both cases, the boiler shuts down as a safety precaution to prevent unburnt gas from building up.
Check if other gas appliances in your home are working to ensure your gas supply is active.Inspect the white plastic pipe (condensate pipe) leading outside to see if it is frozen or blocked.Turn the control knob to the 'R' (Reset) position for five seconds and then back to the 'On' position.
Your boiler has switched itself off because it is getting too hot inside, likely due to a circulation problem or a sensor fault.
Why it happens: This fault occurs when the boiler's internal temperature exceeds a safe limit, triggering a safety switch to prevent damage. It is usually caused by water failing to move around the system quickly enough to carry heat away, often due to a pump failure or a blockage. In some cases, the sensor itself may have failed and is reporting a high temperature even if the boiler is cool.
Check that all radiator valves are fully openEnsure your system pressure is between 1.0 and 1.5 bar on the gaugeTurn the selector switch to 'Reset' for five seconds and then back to the original position
Your boiler has detected that there is not enough water pressure or the pump isn't circulating water through the system properly.
Why it happens: This fault occurs when the boiler's internal sensors detect that water isn't moving through the heat exchanger as it should, which can cause the unit to overheat. The most common reasons are that the water pressure has dropped too low for the system to operate, or the internal pump has seized or failed. Occasionally, a large air bubble trapped inside the pipework can also block the flow and trigger this error.
Check the pressure gauge on the front of the boiler; it should ideally be between 1 and 1.5 bar.If the pressure is too low, use the filling loop valves underneath the boiler to top it up slowly.Bleed any trapped air from your radiators and then re-check the pressure gauge.
Your boiler has detected that water isn't moving through the system correctly, which has caused it to stop working to prevent overheating.
Why it happens: This fault occurs when the boiler's internal sensors detect that water isn't circulating through the heat exchanger, causing a safety shutdown to prevent internal damage. The most common reason is a lack of water pressure in the system, but it can also be caused by a mechanical failure in the pump or a perished rubber diaphragm that fails to trigger the flow switch.
Check the pressure gauge on the front of the boiler; it should be between 1 and 1.5 bar.If the pressure is too low, use the filling loop underneath the boiler to top it up.Bleed your radiators to remove any trapped air that might be blocking water flow.
on the Potterton Performa 24 Eco HE
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