E133 High

Potterton E133 Fault Code

The Potterton E133 fault code means: your boiler has tried to light several times but cannot establish a steady flame, likely because gas isn't reaching it or the spark is failing.. It appears on 14 Potterton models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Interruption of gas supply or ignition failure (5 attempts)

What causes the Potterton E133 fault?

This fault occurs when the boiler has tried to ignite five times but failed to detect a flame, causing the system to shut down for safety. It is most commonly caused by an interruption in the gas supply, a blocked burner, or a worn-out spark electrode that can no longer create a strong enough light. In some cases, a faulty internal sensor may simply fail to 'see' the flame even if the boiler has actually lit.

This fault is frequently seen during extreme cold snaps when the external condensate drainage pipe freezes and backups, preventing the boiler from completing its ignition cycle.

Typical repair cost £120-350 (including labour)

DIY fix possible

Check that your gas meter has credit and the emergency control valve is open.Verify if other gas appliances, like a hob, are working to confirm gas supply.Check if the condensate pipe (outside white plastic pipe) is frozen or blocked.Press and hold the reset button for five seconds.

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Potterton models that show the E133 fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Potterton E133 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