High
neon flashing (Section J) on Baxi Combi 80 Maxflue

Your boiler has detected that it is running too hot and has automatically shut itself down to prevent damage.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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.

What the manual says

Manufacturer manual

Overheat thermostat operated or faulty

From this model's manual
Verified against the Baxi Boiler Combi 80 Maxflue 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 high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Boiler cover options

Avoid the next call-out bill

A cover plan would handle faults like neon flashing (Section J): no call-out fees, no surprise bills.

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