BoilerFaultCodesWhat the manual says
Manufacturer manualApplication of power: Flash > 1/sec in sync with LED 3; Control 'stat open circuit or waiting for demand: On; Fan start up: Flash > 1/sec; Run: On; Pump over-run: Off; Lock-out: Off; Sensor Faults: Off; Reverse polarity: Flash > 1/sec alternately with LED 3.
From this model's manual
Verified against the Ideal/Ideal British Gas 4100 4125 installation & service manual, page 38.
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 10 fault codes on the RD2
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