Low
P.12 on Vaillant ecoTEC plus aquaPLUS

Your boiler is undergoing a temporary waiting process while it determines if the water pressure is high enough to run safely.

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

Not applicable - for GB

From this model's manual
Verified against the Vaillant Ecotec Plus Aquaplus 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.

DIY fix possible

Check the pressure gauge on the front of the boiler.If the pressure is below 1.0 bar, use the filling loop handles to top it up to 1.5 bar.Restart the boiler once the pressure is correct.

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