Vaillant Ecotec Plus 832 Expansion Vessel

[Sandeep89]

Hi Guys,

Had a quick question regarding expansion vessel on a Vaillant Ecotec Plus 832. Was servicing the boiler and upon attaching hand pump to vessle after having drained the boiler, returns and flows isolated and drain off on boiler open, the vessle showed 1 bar charge.

Was wondering why this would be and most of the time when I drain down boiler and attached pump to vessle it shows 0 bar and then I pump until all the water stop from drain off and recharge.

Thanks

 

[John.g]

The EV should have a pre charge pressure of 1 bar, you then open the filling valve to give a filling pressure of 1.5 bar and shut the filling valve. This ensures that there is a water reserve of 1.5 to 2 litres in the EV to make up for any air venting and avoids frequent top ups. Surprising that all show 0 bar which means that they have lost all their pre charge pressure or else the air side is not being given any pre charge pressure, if you do this then it reduces the effective volume of the EV and may result in the PRV lifting when the system heats up.

 

[Deleted member 120897]

How old is the boiler? I’ve been to several that have kept their charge, or has someone charged it before you?

 

[Last Plumber]

It is supposed to be charged to around that. Maybe you're unlucky enough to find them all depressurized.

 

[EvilDrPorkChop]

They usually hold their charge till about 5 year old one the 10 litre ones, and 4 years old on the 8 litre ones. The 7 and 8s that come on the likes of a Pro or 4000 will need doing more often than a 10 litre.

I don't usually touch them to till them time points above, then check them every 2 years after that as the Air doesn't last as long as the pre charged nitrogen.

Don't forget to always check the valve with leak detection, as 9/10 they're usually passing air. So it'll be flat in no time again...

 

[John.g]

The wording at the end of post #1 might suggest that the air side (if showing 0bar) is only pumped until all the water is expelled and then the EV is filled without pre charging to 1bar.

 

[Last Plumber]

Always a good idea to have a bag of Schrader valves and a tool to replace them as Pork chop said.

 

[Sandeep89]

Hi Guys,

Thanks for all the advice. So spoke with customer and they had the EV replaced only few months back so makes sense now as it is still new.

Yeah I have always had vessels on service which have had to be recharged, first one which didn't so got bit baffled. Have also had to replace schrader valves on quite few to due letting by Air.

Appreciate all the help, thanks once again.