Low
D.71 on Vaillant Atmomax

Your boiler is currently set to provide its maximum possible heat output, which can cause it to use more energy and might lead to overheating issues.

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

Maximum setting of heater control knob

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

Locate the heating control knob on the front of the boiler panel.Turn the knob slightly anti-clockwise to a lower setting.Check if the display changes to show a specific temperature rather than the maximum setting.

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