On 25/05/2014 11:47, wrote:
Hello

I wonder if anyone can answer a plumbing question. I just changed the potable water expansion tank for my unvented water system. All seems to be working fine, but I am wondering if I have a missed a step.

I have a zilmet 24l tank pre-charged to 50 psi sitting at the highest point in the system. Obviously the tank was full of air when I first connect it up and I am wondering if I need to bleed the air from the water side of the membrane to fill it up with water? There seems to be no way to do it, and no suggestion it should be done, so I will presumably just contract legionaire's shortly?

Any comments appreciated!

Thanks
Darren

I have 4 Zilmet expansion systems on my install.

The Zilmet 24Litre on Boiler feed loop has just failed (water coming
out of air charge valve) ... so have to obtain replacement next week and
fit.

According to my install instructions - these units are charged with air
when 'not connected' to a pressurised water system ... you would (or at
least should) drain water if you want to check the air pre-charge.

In my case you then fill the pipework and charge up the system to 1 bar
static charge.


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UK SelfBuild: http://uk.groups.yahoo.com/group/UK_Selfbuild/