Low
S.31 on Vaillant Turbomax Plus 828

Your boiler is currently set to 'Summer Mode', which means the central heating is turned off and it will only provide hot water.

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.

What the manual says

Manufacturer manual

Summer mode (heating control knob in off position)

From this model's manual
Verified against the Vaillant Turbomax Plus 824 828e installation & service manual, page 38.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

DIY fix possible

Locate the heating control knob on the boiler control panel (usually the one with a radiator icon).Turn the knob clockwise to your desired temperature setting.The 'S.31' code should disappear as the boiler switches back into heating mode.

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