Low
d.70 on Vaillant ecoTEC Plus 620

Your boiler is currently monitoring or testing the internal valve that decides whether to send hot water to your radiators or your taps.

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

Operation of the diverter valve: 0=Normal operating mode (DHW and heating mode), 1=Mid-position (parallel operation), 2=Permanent setting: He

Engineer required

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

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Related fault codes

F.70View →F.22View →

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