BoilerFaultCodesYour boiler has paused operation because it cannot safely clear waste gases or discharge wastewater produced during the heating process.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Exhaust gas diverter return signal blocks burner operation (only in connection with accessories) or condensate pump faulty, heat demand is blocked
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that waste fluids or gases are not being cleared from the system correctly. The most common reason is a failure in the pump that removes wastewater, or a communication error with the components that manage the exhaust gases. To prevent potential flooding or unsafe operation, the boiler automatically disables the burner until the blockage or electrical fault is resolved.
This fault is more frequent during extreme winter cold, as the external pipe that carries away wastewater can freeze and cause the internal pump to fail.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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