Low
D.7 on Vaillant ecoTEC Regular

Your boiler is displaying an information code to show that the pre-heated water feature for your taps is currently active.

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

Warm start temperature target value

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

What causes this fault?

This code appears when the 'Warm Start' feature is turned on, which keeps a small amount of water inside the boiler hot so it reaches your taps faster. It is not a fault, but rather a status message letting you know the unit is briefly firing up to maintain this internal heat. If you see this frequently, it simply means the boiler is keeping itself ready for your next hot shower.

DIY fix possible

Locate the 'Hot Water' dial or button on the control panelTurn the dial slightly clockwise to activate or counter-clockwise to deactivate the pre-heat (Warm Start) functionNo further action is required as this is a status indicator rather than a fault

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