Low
d.0 on Vaillant ecoMAX 635

Your boiler is currently operating normally and is simply indicating that it is running at a lower workload to maintain your desired temperature.

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 system part load

Engineer required

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

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