Low
S.31 on Vaillant Turbomax Plus

Your boiler is currently set to 'Summer mode,' which means it is waiting to provide hot water but has temporarily turned off the central heating.

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 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 front panel of the boiler.Turn the knob clockwise to your desired temperature setting.Observe the display to ensure the code disappears and the boiler initiates a heating cycle.

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