Lowering Expansion Vessels on Unvented System

Lumen · Feb 28, 2020

Hi Chaps,

Wife has been nagging me about having shelves in an airing cupboard for about a year now.
We've had unvented cylinder fitted last year and both expansion vessels are very high to fit a towel shelve (as it will be just below the top of door frame).
Can the expansion vessels be lowered so the top of the expansion vessels hit the red line drawn in the picture attached? Are there any minimum requirements for fitting expansion vessels on unvented cylinder?
I would really appreciate advice on this if you're G3 qualified, before I call a plumber in.

Best Regards,
Lumen

SJB060685 · Feb 28, 2020

Lowering the expansion vessels isn't a problem providing you have space. It looks pretty tight in there and if you do decide to go for it then like you say you'll need a G3 guy as you'll be adjusted both unvented supply and heating pipework

Scott_D · Feb 28, 2020

Yes it can be done
If you post a location, someone here might be near you

king of pipes · Feb 28, 2020

As above yes it can be done ? but i would build the sheving around whats there already ,if you move them lower they will still be there just lower removable slated shelving is the way . Kop

moonlight · Mar 17, 2020

I think there is not a great deal of clearance below the proposed shelf. have you measured the height of the units and allowing for connection of pipework?

Stigster · Mar 17, 2020

Remember on the potable side you must have a continuous fall on the pipework from expansion vessel to connection at cylinder. You must not create a "silt trap". The fall does not need to be big and I suspect that even just level is OK for practical purposes. See link for best practice on this subject.