BoilerFaultCodesTechnical description
domestic hot water demand
What causes this fault?
This status occurs when the external cylinder thermostat or the boiler's internal controls detect that your hot water tank has cooled down and needs reheating. The boiler physically switches its internal valves to direct heat toward the water cylinder rather than your radiators to ensure you have a full supply of hot water for taps and showers.
DIY fix possible
Check if your hot water timer or thermostat is currently calling for heatWait for the boiler to finish heating the cylinder to see if the code changes to a standby modeNo action is required as this is a normal status indicator
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