BoilerFaultCodesThe 6 most common faults
Your boiler has too much water inside it, which is causing the safety valve to leak or trigger to protect the system from bursting.
Why it happens: This fault occurs when there is too much water pressure in the system, often caused by the filling loop being left slightly open or a internal leak between the domestic hot water and central heating sides. It can also happen if the expansion vessel has lost its air charge, meaning there is no room for water to expand as it heats up. As a result, the pressure rises rapidly until it forces the safety valve to open and discharge water.
Check that the filling loop valves are fully closed and not letting in more water.Release excess pressure by bleeding a radiator into a container until the gauge reads between 1 and 1.5 bar.Check the discharge pipe outside for signs of leaking.If pressure continues to rise after bleeding, call a Gas Safe engineer to inspect the expansion vessel.
Your boiler has no power and the control panel lights are completely switched off.
Why it happens: This fault occurs when the electrical supply to the boiler's internal components is interrupted, meaning the control board cannot receive any power. The most common reasons are a blown internal glass fuse caused by a component short-circuiting, a faulty main circuit board, or a failure in the power selector switch. Essentially, the 'brain' of the boiler has lost its electricity and cannot tell the system to start up.
Check if the boiler's power switch is turned onCheck your home's main fuse box/consumer unit to see if a circuit has trippedCheck the fuse in the spurred power socket next to the boiler
Your boiler has become too hot and has automatically shut down as a safety precaution.
Why it happens: This fault occurs when the water inside the boiler exceeds a safe temperature, causing the system to shut down to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the heat exchanger that restricts flow. It can also be caused by a faulty internal sensor that is incorrectly reporting the temperature.
Wait at least 30 minutes for the boiler to cool down completely.Turn the main selector switch to the 'Reset' position and hold for 5 seconds.Turn the switch back to the 'On' position and check if the burner reignites.Ensure all radiator valves are open and the system pressure is between 1 and 1.5 bar.
Your boiler has tried to fire up but could not light the flame, causing it to shut down for safety.
Why it happens: This fault occurs when the boiler's internal sensor fails to detect a flame after several attempts to start. The most common reasons are a lack of gas reaching the burner, a faulty spark that cannot ignite the gas, or a sensor that is too dirty to see the flame that has been lit.
Check that your gas supply is turned on at the meterTurn the control knob to the 'Reset' position for five secondsSlowly release the knob back to the 'On' position and wait for the boiler to restart
Your boiler has stopped working because the water pressure inside the system has dropped too low.
Why it happens: This fault occurs when the internal sensors detect that there isn't enough water volume to safely transfer heat around your home. The most common reason is a slow leak in the radiator network or pipework, but it can also happen if you recently bled your radiators without topping up the pressure afterwards.
Locate the filling loop (usually a silver flexible hose) underneath the boiler.Slowly open the one or two taps/levers on the hose until you hear water entering.Watch the pressure gauge and close the taps once it reaches between 1.0 and 1.5 bar.
Your boiler has likely become too hot or water is not circulating correctly, causing it to shut down for safety.
Why it happens: This fault occurs when the water inside the boiler reaches an unsafe temperature, triggering a safety sensor to shut the system down to prevent damage. The most common reasons are a pump failure that stops water from moving or a blockage in the pipework preventing heat from escaping the boiler.
Rotate the selector switch to the 'Reset' position for 5 seconds, then back to its original setting.Check that all radiator valves are fully open to ensure water can flow.Verify that the system pressure is between 1 and 1.5 bar on the pressure gauge.
on the Potterton Performa 24
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