Check valves and mixer taps

[chris watkins]

I noticed that the mixer tap was making the sound of running water when the main valve was open but the tap and the spray attachment was closed. I theorised that cold water was running into the hot pipe, as it is much higher pressure. I went online and concluded that the solution was a check valve.
I bought one, fitted it . and I still get the sound.
Is it the cold supply going into the hot pipes? If not, what is it - and if so, why didn't the check valve stop and what should I do?

I would not presume to come & start telling you how the Law should be applied, oh yes I could look it up & quote something back to you, I might even be able to sound impressive but it is not my area of expertise, so why would I do that?
If I make a mistake I hold my hands up & admit to it, you sir made a mistake. By your own admission, you installed a mixer tap in which hot & cold water mix within the body & yet failed to install a single check valve on both the hot & the cold supplies as required.

The fact that you are a Lawyer speaks volumes about how you act & treat folk, it is a reminder why I never do work for them.

 

[swingthelead]

I would not presume to come & start telling you how the Law should be applied, oh yes I could look it up & quote something back to you, I might even be able to sound impressive but it is not my area of expertise, so why would I do that?
If I make a mistake I hold my hands up & admit to it, you sir made a mistake. By your own admission, you installed a mixer tap in which hot & cold water mix within the body & yet failed to install a single check valve on both the hot & the cold supplies as required.

The fact that you are a Lawyer speaks volumes about how you act & treat folk, it is a reminder why I never do work for them.

You've been quite hostile, frankly, and now you post specifically to have a go at me, and then get snide about all lawyers. Not very welcoming.

You've just posted that such taps can be fitted - with check valves. When I realised the problem re the tap I fitted a single check valve but IT DOESN'T SEEM TO BE WORKING, and that's why I started this thread. I also posted that I'm willing to replace the tap if I have to, but I don't want to spend the money if it isn't necessary.

 

[Shower Engineer]

From the photo you posted I would say you have placed the NRV in the hot supply. Am I correct or is it fitted in the cold supply?

 

[swingthelead]

From the photo you posted I would say you have placed the NRV in the hot supply. Am I correct or is it fitted in the cold supply?

You're right, it's in the hot supply.
I fitted it there because it seems that the cold water is pushing into the hot pipe. I think this because i) it's logical, anybody can see the cold pressure is far higher; ii) when I run the tap until the water comes hot, and then (briefly, and only for test purposes) put the tap in the 'Warm' position, and then turn it to back to 'Hot', I get cold water for several seconds. (Otherwise, I have the tap 'Off' when I switch from Hot to Cold and back, so there's no mixing; for 'warm' water I put hold and cold separately into the bowl.)

 

[Shower Engineer]

In that case it probably is a faulty NRV, take it out and see if you can blow through it both ways!
The advice you have already been given above is correct. You should send it back and install something that is fit for purpose.

 

[swingthelead]

Thanks for your help. I probably can't send it back; it's too late to exercise rights under the Consumer Protection Act, and the tap is, apparently, legal to sell. So the vendor can say: it works as it's supposed to work. So first I will try replacing the check valve.

Is it right that check valves will reduce the pressure? I read somewhere that some plumbers increase the pipe size, fit a 22mm check valve, and then change back down to 15mm, to avoid or minimise pressure drop. Does that work?

 

[swingthelead]

I just logged on, thinking of posting another query. I noticed a recent question posted about non-return valves so I thought I'd read it.
Shortly, along came the plumbers whose attitude dial seems stuck on 'Snide', and started posting unpleasantly about the OP.
I was looking through the home page and I found this:
"UKPlumbersForums.co.uk provides free plumbing advice to both professional and DIY British plumbers, and professional heating engineers."
The key word there is 'DIY'. If this were a forum for qualified plumbers only, fair enough. But it's not necessary to post hostile and aggressive criticism of people because - in his case and mine - we didn't immediately accept the generally pointless advice 'Consult a plumber'. If you don't feel like helping one particular member, just find another thread.

I felt very unwelcome here after my post; and I bet the other guy did too. If that's what everyone here wants, then so be it.

 

[Riley]

Not being funny my friend but if you browse. there are loads of very helpful type responses from both pros and diyers. Sometimes frustration kicks in when you have told someone how to fix a problem and they go with a usually cheaper ineffective option. In addition many people get precious when they don’t hear what they want to hear which in some cases is get a pro in. The true pros here will never suggest or condone a bodge or a quick fix. We pride ourselves on providing informationpertaining to a correct installation or sometimes having to start again when this isn’t possible. I’m sorry if this has made you feel unwelcome but you have to look at both sides of the coin and perhaps not just focus on one thread which may not give the whole picture

 

[Burger]

Hi,

I’m sure it’s not what everyone on here wants. Sometimes we offer advice that isn’t to say one advice fits or suits all. Don’t forget:
We are doing this for no remuneration whatsoever and in our own time.
We are working blind with the descriptions and photos that OPs send in.
We are clearly stating facts and regulations that we as plumbers , heating/gas engineers have to adhere to and what we expect the OP to understand and to adhere to.
You have been offered advice and it’s up to you as to what you do with that advice.
Sometimes it’s best to suggest consult a plumber as they can visually see what is wrong and why it’s happening.

Looking at one of your replies, the reason it remains legal to sell is because it’s down to the installer to prove it meets the criteria of being accepted for potable (drinking) water and the criteria laid down within the water supply (water fittings) regulations 1999.

If you’re check valve has failed, then it has failed. Try another one. If that doesn’t work then reverting back to what I have said above, might be best getting a plumber as we are working blind.

Thnaks, for reading.