Low
d.08 on Vaillant Turbomax Plus 824/828E

This code simply indicates that your boiler is currently in standby mode because it hasn't been asked to provide any heating or hot water at this moment.

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

External controls heat demand 0 = open, no demand; 1 = closed, demand

From this model's manual
Verified against the Vaillant Turbomax Plus 824 828e installation & service manual, page 39.
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

Check your room thermostat or smart controller settings to ensure a temperature higher than the current room temperature is requestedTurn up the heating dial on your wall controller to see if the boiler activatesEnsure your programmer is set to 'On' for heating or hot water

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