Vaillant EcoTEC 831 issue

Jamie Harvey · Dec 27, 2021

Hi, looking for some help/advice if possible.

Mum has a Vaillant EcTEC 831 ( VUW GB316/3-5 ) and the pump is constantly running. It was serviced in Sept when it started? Normally itwoulonly run when heating or hot water was required.
I have managed to turn off the Comfot Mode but am unable to find out how to turn off the ECO mode. Could anyone please advise.

Many thanks

Scott_D · Dec 27, 2021

Comfort is hot water preheat.
Is eco the same as preheat off?

Jamie Harvey · Dec 27, 2021

scott_d said:
Comfort is hot water preheat.
Is eco the same as preheat off?

Yes, I think it is

Deleted member 120897 · Dec 27, 2021

Eco mode? Is this setup as a combi boiler or system boiler? Pump overrun lasts for 5 minutes by factory default, but is changeable. Try pressing the i and plus button simultaneously, this should bring up the d settings, the using the plus button, scroll through to d.1 (usually pressing plus twice) and this will give a numerical value, what is it?