Low
d.41 on Vaillant ecoTEC Plus 836

Your boiler is simply displaying the current temperature reading of the water returning to it from your radiators; this is an information code rather than a fault.

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

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

d.40View →

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