BoilerFaultCodesYour boiler is working normally and simply indicating that you are currently running a hot water tap or shower.
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: Domestic hot water being supplied
What causes this fault?
Small 'd' is not a fault; it appears when the boiler's flow sensor detects that you have turned on a hot water outlet. This indicates that the internal diverter valve has successfully shifted priority to the hot water heat exchanger to warm the water for your taps.
This display code may be seen more frequently in winter as users tend to run hot taps for longer and take warmer showers, but it occurs year-round during normal use.
DIY fix possible
Turn off any running hot water tapsCheck if the display changes to '0' or 'C' once the tap is closedNo further action is required as this is a status indicator, not a fault
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