High
H.01 – .05 on Baxi Suprima 40

Your boiler is overheating because the water is not moving through the system fast enough or the sensors are misreading the temperature.

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

Difference between the flow and return temperature is too high, sensor error or insufficient circulation.

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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