BoilerFaultCodesWhat the manual says
Manufacturer manualwaiting time: temperature difference flow - return sensor too high (Check thermistor fit). Check flow & return thermistor connections to pipes. Check harness connection to thermistor. Check harness wires are not trapped between any internal components.
From this model's manual
Verified against the British Gas/British Gas 330 installation & service manual, page 47.
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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Related fault codes
All 27 fault codes on the 330+
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