BoilerFaultCodesPotterton 133 Fault Code
The Potterton 133 fault code means: your boiler has tried to light several times but cannot establish a stable flame, meaning it cannot provide heating or hot water.. It appears on 1 Potterton model in our database.
Technical description: Interruption of gas supply or ignition failure (spark at ignition electrodes for up to 5 seconds and for 3 attempts)
What causes the Potterton 133 fault?
This fault occurs when the boiler fails to detect a flame after several attempts to spark, causing the system to shut down for safety. The most common reasons are a temporary interruption in your gas supply, a build-up of carbon on the ignition probes, or a component failure that prevents gas from flowing correctly into the burner.
This fault is frequently seen during extreme cold snaps, as the external condensate pipe can freeze and back up, preventing the boiler from lighting.
DIY fix possible
Check that your gas emergency control valve is turned on and that other gas appliances work.If you have a pre-payment meter, ensure you have active credit.Try resetting the boiler by turning the selector switch to the 'R' position for five seconds, then back to its original position.In freezing weather, check if your external plastic condensate pipe has frozen and needs thawing with warm water.
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Gas Safe Register →Potterton models that show the 133 fault code
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Source
Potterton 133 fault code information on this page is sourced and cross-checked against the official Potterton service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026