Low
d.70 on Vaillant Home System

Your boiler is currently set to a specific service mode that forces the internal valve into a fixed position rather than operating normally.

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

DIY fix possible

Press the Menu button on the control panelNavigate to the Installer Level or Settings menuLocate setting d.70 and change the value back to 0Confirm and exit the menu to restore normal operation

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Related fault codes

d.00View →d.01View →

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