BoilerFaultCodesYour boiler is currently in 'Preheat' mode, meaning it is simply warming up a small amount of water within the unit so that hot water arrives at your taps more quickly.
This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.
Technical description: DHW preheat
What causes this fault?
The 'h' code is not caused by a component failure or a system error. It is triggered when the boiler's internal software decides to briefly fire the burner to keep the heat exchanger warm. This ensures that when you turn on a tap, you don't have to wait as long for the water to reach a comfortable temperature.
DIY fix possible
No action is required as this is a normal operating message, not a fault.If you wish to turn this feature off to save energy, locate the 'Preheat' button or dial on the control panel and switch it to the 'Off' position.
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