D.3 Low
Your boiler is simply showing that it is currently preparing or providing hot water to your taps or cylinder.
Technical description: Hot water flow temperature reading
Typical repair cost: £0 (including labour)
DIY fix possible
Check if your hot water is running or the cylinder is heating upWait for the hot water demand to finishObserve if the screen changes back to a temperature or different status once finished
Protect yourself from future repair bills
A boiler cover plan would cover faults like D.3 — no call-out fees, no surprises.
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