OK finally getting round to fitting the electric shower in the bathroom (thanks for previous advice). I need to fit an isolating valve (to allow the water to be turned off for maintenance) and a check valve (to prevent backflow of the water from the shower) in the mains water pipe to the shower. The question is can I get one valve that does both jobs ? or do I have to fit the two valves separately ?

thanks

Most valves that I have ever encountered have never done this type of thing. A ball valve is best for shut off if you can get one... little movement or force required but slightly more expensive. Worth every penny though!

Frankly.....
Fit a ball-type isolator and don't worry about a check valve.

i thought that non return valves were to prevent hot water entering the cold system? this isnt a major issue with electric showers, only mixer showers. Most mixer taps have a built in pressre reducing valve in the hot side, to prevent this happening. Certainly the ones i install do!

http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=76242&id=13483
for maintenance purposes. You only need a check valve in an outside tap like the bibcock type where you would use a hose.

This is the point though. The water regulations demand that you take steps to prevent back-syphonage where you can contaminate their precious water. Showers generally have a ring on the slide rail somewhere which prevents the handset reaching the spillover level of the tray so that (big breath)

..if the waste blocks and the tray fills up and you drop the handset and the mains water pressure drops and someone at a lower level than you draws off a volume of water large enough to suck the water out of your pipes...........(another breath)

..then the dirty water from your shower will be i the drinking water supply.

thanks,

I just fitted the isolator valve and the ring thing on the slide rail that came with the shower (. All ready for the electrician to come and connect it up.