Low
D.3 on Vaillant Atmomax

Your boiler is currently showing the temperature of the hot water as it flows through the system, which is a normal status message rather than an error.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

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.

What the manual says

Manufacturer manual

Hot water flow temperature reading

Shared across the range
This code is shared by the boilers in this range, which use the same control board. It may not be printed in this exact variant’s manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Check if a hot water tap is currently runningWait for the boiler to finish its current heating cyclePress the 'i' button to return to the main pressure or temperature display

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D.0View →D.4View →D.40View →

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