Low
d.25 on Vaillant Turbomax Plus 824/828E

This code simply indicates that your boiler's 'pre-heat' feature, which keeps water hot for faster delivery to your taps, is currently switched off.

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

Warmstart status (turboMAX plus) 1 = ON; 0 = OFF

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

Locate the 'eco' or 'warmstart' button on your boiler's front control panel.Press the button to toggle the warmstart status to ON.Check if the display now shows the warmstart icon or indicator light.

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