Low
d.08 on Vaillant Turbomax Plus 828

Your boiler is currently idle because it is not receiving a signal from your thermostat or timer to turn on the heating or 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

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 is set to a temperature higher than the current room temperature.Ensure your heating timer or programmer is set to 'On' for the current time period.Verify that any smart heating controls are connected to Wi-Fi and communicating correctly.

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