vailant Expansion vessell presure?

[Robert Needham]

Can anyone advise me on what pressure should be on a Vaillant Ecotec Plus expansion vessel, please? I can't see the sticker on it.

 

[Johntheo5]

Try 0.75bar prepressure and 1.25bar filling pressure, a 10L EV pressure should then not rise above 2.0bar with a 120L system vol or above 2.3bar with a 150L system, when hot.

 

[Madrab]

Should/could be done as part of a boiler service TBH. The EV on an Ecotec is in behind the room sealed case and it should really be a GSR engineer in there doing the work.

 

[dormermike]

Try 0.75bar prepressure and 1.25bar filling pressure, a 10L EV pressure should then not rise above 2.0bar with a 120L system vol or above 2.3bar with a 150L system, when hot.

Sorry to OP if I hijack but I've a 14 rad system and the cold pressure is 1.4bar and with the heating on it goes to 2.7 bar max, but usually 2.2bar, depends on how much heat demand I think. It's a 111-w boiler and some old rads, 90's stelrads mostly, and one is 3m long but no idea on total volume, always presumed 100L. It's recently been converted from a open vent. I believe the EV is 10L. Should it have a second EV fitted ?

 

[Madrab]

Sorry to OP if I hijack but I've a 14 rad system and the cold pressure is 1.4bar and with the heating on it goes to 2.7 bar max, but usually 2.2bar, depends on how much heat demand I think. It's a 111-w boiler and some old rads, 90's stelrads mostly, and one is 3m long but no idea on total volume, always presumed 100L. It's recently been converted from a open vent. I believe the EV is 10L. Should it have a second EV fitted ?

Yes, would recommend a 2nd EV. A 12L should be fine and get the internal one checked to ensure it's set correctly too.

 

[dormermike]

Yes, would recommend a 2nd EV. A 12L should be fine and get the internal one checked to ensure it's set correctly too.

Thanks. Boiler only been in a month so I'd hope the installer set it correctly, they are viessmann installers. I'll speak to them about a 2nd one next time they're here for other work.

If I leave it, will a radiator burst or what is the risk? Thanks for the help

 

[Mottie]

Should/could be done as part of a boiler service TBH. The EV on an Ecotec is in behind the room sealed case and it should really be a GSR engineer in there doing the work.

I have an EcoTEC plus boiler (heat only) in a sealed system and that has an external EV.

 

[Madrab]

Thanks. Boiler only been in a month so I'd hope the installer set it correctly, they are viessmann installers. I'll speak to them about a 2nd one next time they're here for other work.

If I leave it, will a radiator burst or what is the risk? Thanks for the help

Radiator shouldn't burst if it's all installed correctly but you are reaching the limit for the PRV to start lifting.

I have no idea what they were thinking about when they thought that the internal EV would have been sufficient, for what sounds to be a reasonably good sized system. You could probably drop the cold pressure to 1 bar, just to keep the high limit down a bit. Just bleed a rad down until the gauge hits 1 bar.

I'd get in touch with them sooner rather than later as having the system running up to that pressure is putting stress on everything, not ideal. Especially if it's only been in a month!!

 

[Madrab]

I have an EcoTEC plus boiler (heat only) in a sealed system and that has an external EV.

Indeed, I though all the Plus' were either combi or system .... In saying that they do an OV version too don't they, so no reason not to do a HO too I guess.

 

[dormermike]

Radiator shouldn't burst if it's all installed correctly but you are reaching the limit for the PRV to start lifting.

I have no idea what they were thinking about when they thought that the internal EV would have been sufficient, for what sounds to be a reasonably good sized system. You could probably drop the cold pressure to 1 bar, just to keep the high limit down a bit. Just bleed a rad down until the gauge hits 1 bar.

I'd get in touch with them sooner rather than later as having the system running up to that pressure is putting stress on everything, not ideal. Especially if it's only been in a month!!

Thanks again. I've got it on at the moment, is at 2.6bar and the boilers not even working particularly hard. I'll send a photo of the pressure gauge just almost about to tip into the red and see what they say. They've been great so I think they'll be fine adding a new EV, id expect to pay of course.

Will drop the pressure to 1bar in meantime.

Thanks again!!

 

[Johntheo5]

A 10L EV is just a little on the mean side but still quite adequate with the proper precharge & filling pressures.
I can't imagine your system being > 150L so........... precharge/filling pressures of 1.0/1.4bar will give a final pressure of 2.4bar
precharge/filling pressures of 1.0/1.0bar will give a final pressure of 1.64bar but no water reserve to take up any tiny leaks or micro air bubble collapse.
A precharge/filling pressures of 0.75/1.0bar will give a final pressure of 1.77bar with a nice little water reserve of 1.25L, if this is used up and the filling pressure falls to 0.75bar then the final pressure will actually fall to 1.31bar.

 

[Robert Needham]

I found the ridiculousely thin copper tube to the dial was broken, when I dropped the bottom door I got sprayed with water ha ha.
The tube was traight and got caught on the inside of door, i replaced with new one and kept it slightely coiled, filled to just under 1 bar, seems ok now (cross fingers).