Low
d.41 on Vaillant Home System

This is an information code rather than a fault, showing you the temperature of the water as it returns to the boiler from your radiators.

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.

Technical description

Heating return temperature: Current value

DIY fix possible

This fault may be fixable without an engineer. Check your manual first.

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