BoilerFaultCodesThe 6 most common faults
Your boiler has detected that the water pressure inside your heating system has risen above the safe operating limit.
Locate a radiator in your home that has a bleed valve.Place a cloth or small container under the valve.Open the bleed valve slightly to release a small amount of water until the pressure gauge on the boiler drops back into the green zone (usually 1.0 to 1.5 bar) and then close the valve.
Your boiler has lost the necessary water pressure, so it has safely shut down to prevent damage.
Locate the external filling loop, usually a silver flexible hose connected to two valves under the boiler.Gradually open the valves to let water into the system until the pressure gauge reads between 1.0 and 1.5 bar.Close both valves tightly and ensure the pressure remains steady.
Your boiler has lost the link to the valve that controls the gas supply, meaning it cannot ignite to provide you with heating or hot water.
Full guide for 09Your boiler has lost the ability to accurately measure the temperature of the water circulating through your radiators, so it has shut down to prevent overheating.
Full guide for 20Your boiler has detected a communication error with its exhaust sensor, causing it to shut down for safety reasons.
Full guide for 28Your boiler is struggling to accurately read the temperature of the water returning to it, which prevents the system from heating your home properly.
Full guide for 40on the Potterton Ultra 12 System
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
Avoid the next call-out bill
Monthly cover means no unexpected bills when your boiler breaks down.
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