Shower pump location and pipe routing

by **AlNic** » Sat Dec 15, 2007 10:00 pm

I'd like to fit a shower pump in my airing cupboard to supply a shower in the bathroom across the hallway. I can't route the pipework under the floor and I really don't want to put the pump in the loft. Therefore, can I route the pipework from the pump in the airing cupboard up into the loft over the hallway and down into the bathroom? Could this cause airlocks and should I fit air vents?

by **peter the plumber** » Sun Dec 16, 2007 7:30 pm

I am having a hard time seeing what the problem is here.

You have a hot water cylinder that is supplying your bathroom with hot water, so why not just install the pump on the hot water pipe feeding the bathroom?

Or is the cupboard too small?

by **AlNic** » Sun Dec 16, 2007 9:19 pm

The instructions for the pump say that it is solely to supply a shower; and for some reason the cold supply for the bathroom is in 15mm pipe, the pump requires 22mm supply. The plumbing in this house is not what you'd expect, certainly isn't logical and would take too long to explain exactly how it's laid out. I just need to know if I can route the pipework as I originally described.

by **marrtin** » Sun Dec 16, 2007 11:48 pm

You cannot use the same feed to the shower as the supply to the bathroom hot water - there must be a dedicated supply to the pump from the hot water cylinder via an Deleted or Surrey flange or at the very least, a very close connection to the hot water outlet. Of course, there needs to be a cold supply from the header tank too.

In brief, you will have no problem routing the pipes as you suggest. Any air will be quickly forced through the pipework. No vents required.

by **mattcambs** » Thu Dec 27, 2007 8:25 pm

[quote="marrtin"]You cannot use the same feed to the shower as the supply to the bathroom hot water - there must be a dedicated supply to the pump from the hot water cylinder via an Deleted or Surrey flange or at the very least, a very close connection to the hot water outlet. Of course, there needs to be a cold supply from the header tank too.
[/quote]

Can the cold supply to a pump be teed off the cold supply pipe that goes into the hot water cylinder?

by **marrtin** » Fri Dec 28, 2007 9:51 am

No, unfortunately not, the problem would be that the pipe has insufficient diameter to supply the cold and replenish the cylinder at the same time. Air would be sucked down the expansion pipe into the feed.

The pipe can only just supply the hot which is why you are supposed to use the E-s-s-e-x or Surrey flange. If you decide not to (and you probably could get away with it), tee off for the hot as close to the cylinder top as possible.