plumbing query

neilandvicky

Hello all. I am just about to replace the cold water tank in the loft (its beginning to rust through). I have drained the tank and was just about to cut through some of the pipework when i thought i ought to check that i had all the correct joiners/reducers. my query is that the the cold water feed from the tank to the immersion appears to be 21.5mm which seems quite a strange size? will a 22mm push fit fitting be ok on this ? or is it a strange imperial size (not sure what 0.84 inches equates to )

hope someone can help.

many thanks , neil

crazyguy

http://www.plumbingpages.com/featurepages/

mikey72

Sounds like 3/4 imperial pipe, not 22mm.
You can get a pushfit 22mm to 3/4, or use a 3/4 compression, or solder 22mm to 3/4 adapter

keystone

Agree with mikey sounds like 3/4 inch pipe. You can also use a 22mm compression fitting with a 3/4 inch olive in it. Chuck the 22mm olive away or save it for future use. It is copper and not steel barrel though isn't it?

Cheers

neilandvicky

22mm compression fitting with 3/4" olive seems to do the trick and appears to be leak free. Problem with the cold water tank overfilling not resolved though by fitting new tank and ball float valve? over night the tank is still overflowing. problem appears to be a failure of the bathroom wash basin mixer tap. Mains pressure cold water seems to be forcing its way slowly through the hot tap and back-filling the cold water tank. Has anyone had this happen to them before? i would have thought that the tap would be designed to stop this happening?

boingsaidzebedee

Saw this once before on a shower mixer.Can't remember rightly but think problem was because the shower had a low pressure cartridge because of hot water cylinder.
In this case hot and cold should have both been tank fed to equalise pressure.
Maybe change for high pressure cartridge ?

andyhop

Stick a couple of check valves in the tap supplys

Most taps require equal/balanced pressure and not all come with check valves built in