Emergency
OVERHEAT LOCKOUT on Potterton Promax 15/2 HE Plus

Your boiler has automatically shut down because it has detected that it is getting dangerously hotter than it should be.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

What the manual says

Manufacturer manual

Lights: Flash Off On. Possible causes: black stat on flow pipe faulty, fan stat faulty, wiring from PCB to thermostats faulty, thermistor faulty, or combustion chamber door seal damaged.

From this model's manual
Verified against the Potterton Promax 15 2 He Plus installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E110View →E160View →

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