Do I need a non-return valve between my cold water supply and my dishwasher?

dnpark38

I'm having nasty tasting water from my tap.

Water supplier say it is the rubber feed pipe from both my dish washer and washing machine as they will be blowing up during the night time higher water pressure. Then when I run kitching tap this now bad water tasting comes back out through my tap.

To prevent I should fit non return valves.

GDB2222

https://forums.moneysavingexpert.com/discussion/comment/82132165#Comment_82132165

That's interesting. Surely, lots of people have a dishwasher connected, and not many have check valves. (We are in that position.) So, why isn't this a more commonly reported issue?

EssexExile

https://forums.moneysavingexpert.com/discussion/comment/82132241#Comment_82132241

It's not more commonly reported because it's not a thing. I've no idea what "blowing up" during the night means but whatever it is, it doesn't happen. The hoses aren't rubber they are plastic, unless they are very old in which case they are probably leaking too!

ComicGeek

Cut and paste of the explanation from Anglian Water website, rather than me having to retype it:

"In April 2017, the Water Regs UK changed the installation requirements of the Water Supply (Water Fittings) Regulations 1999. At the point where an appliance, such as a dishwasher or washing machine, is connected to the water supply, it will need an additional Double Check Valve (DCV) installed.

Historically, it was assumed all domestic appliances were fitted with DCVs"

You could test the theory by isolating the water to the appliances for the night, you should have some form of isolating valve for the pipe connections. It's possible I guess, but then I would have thought the bad tasting water would clear quickly when the tap's running.