Search the forum,

Discuss Check valves and mixer taps in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Messages
15
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?

Thanks for reading.
 
Can't manage that right now. :(
If it helps, this is the tap:
this is the check valve
and it's fitted 3 inches or so below the tap tail on Hep2O 15mm pipe running about 12" from a connector with the old copper pipe.
 
Judging by the tap, being the kitchen sink it could be a burst water main. Turn your stopcock off and see if it still make the noise but only louder, this should confirm a burst. If not did you fit the check valve on the hot?
 
Well the way to be sure is turn off your internal stopcock and see if your water meter still turns
 
Judging by the tap, being the kitchen sink it could be a burst water main. Turn your stopcock off and see if it still make the noise but only louder, this should confirm a burst. If not did you fit the check valve on the hot?

Hence the request for images. Supposition sucks :)
 
pipes2.jpg
tap2.jpg
Here's the pictures.
It's a communal hot water system in a block of flats; heated in a single boiler and then circulated through all the flats. The noise only happens when a) the main tap valve is more or less central (ie, hot and cold flow) but b) both the adjustable tap and the spray head are off.
 
New facts.
Turned the main selector to Hot; turned on the tap and left it open until the water ran hot. Turned the selector to the mid-point and heard the 'water rushing in pipes' noise. The water coming out of the tap turned cold - not warm, not cool, but full cold. After turning the selector back to Hot, the tap ran cold for several seconds before warming up to the previous hot temperature.
It must be the cold water running into the hot pipe, surely? The check valve isn't working. Should I replace it?
 
STL
1 - The tap you have purchased needs non return valves in both lines as the supplies mix within the tap body. Unfortunately, it is not a WRAS approved tap otherwise those would have been included. If your supplies are not perfectly balanced then without those NRVs it is not safe to install due to what you are currently experiencing.
2 - The data on the installation sheet is completely incorrect too. As a high pressure tap requiring a minimum of 0.5bar to operate it means you need a MINIMUM distance of 6 metres from the underside of your loft tank to the highest point of your tap for it to flow reasonably. The, so called, instructions say 2m.

What you've bought is 'not very good', contravenes water regulations as fitted and has caused you these problems. Unfortunately UK law means they are able to sell this rubbish with impunity. YOU however become the law breaker by fitting it.

My advice. Go buy a tap that is WRAS approved by a reputable manufacturer. Sorry.
 
There is no loft tank. Mains comes straight into the flats.
I recognise the problem, but I'm not about to pay to replace the tap until I understand the why this is happening. Problem solving requires identifying where the problem is, because if you assume where it is, you probably end up solving several non-problems before you solve the actual problem.
It seems the problem is with the check valve.
I'm not opposed to putting a check valve on the cold supply, but that's not going to stop the cold pushing into the hot supply, surely?
So the question remains: how come cold water is going through the check valve in the wrong direction?
 
There is no loft tank. Mains comes straight into the flats.
I recognise the problem, but I'm not about to pay to replace the tap until I understand the why this is happening. Problem solving requires identifying where the problem is, because if you assume where it is, you probably end up solving several non-problems before you solve the actual problem.
It seems the problem is with the check valve.
I'm not opposed to putting a check valve on the cold supply, but that's not going to stop the cold pushing into the hot supply, surely?
So the question remains: how come cold water is going through the check valve in the wrong direction?

The 'problems' you have are two fold:
1 - you have a tap unfit through both performance & regulation for UK plumbing
2 - you choose not to listen
Patently however you know better. It must have been pure chance that you landed at a plumbing forum asking questions. Crack on pal. I hope it's only your own you end up poisoning.
I'm out.:rolleyes::mad:
 
I am with Dave on this one.
No help or advice from me apart from go find a Plumber who has their Water Regs.
Public health should not be left to some Swing er who wants to problem solve after the event, next they will be leaving that hose in a sink full of dirty water.
I pity the others in that communal block of flats!!!
 
It could be a faulty check valve yes.
Thank you. Not being a plumber, I have no conception of how likely it is that such a valve is faulty.
As for the other people offering 'advice' to me: I am a lawyer by profession. I often offer assistance on legal forums. If someone has a problem with a second-hand car, they don't find it very helpful if my advice is 'buy another car'. They want to know what their rights are as against the car dealer.
I've looked up the Water Regulations, and as far as I can see
"It is not illegal to install a product such as water fittings in the UK without the WRAS mark but you may have to prove compliance in other ways. It is legal to design, manufacture, import or trade in non-approved items. It is legal to use non-approved fittings."​
In this case, water from the cold water system - which is potable - is possibly finding its way into the hot supply, which may not be. (In the house which my ex-wife and I built in the 1990s, in which - amongst other things, she did the electrics and I did all the plumbing and heating - the hot water was potable.) That's not a health risk.
I'm not in breach of 3(1), 3(2) of the Regulations, section 6 doesn't apply to me, and the tap isn't listed in the Table in section 5(1), so I haven't committed an offence.
I have to fix the problem, and if I must, I'll get an approved tap. But if I can comply with the Regulations by replacing a £5 defective valve, I'd rather do that than spend £100 on a new tap. I don't think that's an unreasonable attitude to take. Work on this flat is costing me a bloody fortune as it is!
 
I am with Dave on this one.
No help or advice from me apart from go find a Plumber who has their Water Regs.
Public health should not be left to some Swing er who wants to problem solve after the event, next they will be leaving that hose in a sink full of dirty water.
I pity the others in that communal block of flats!!!
Thanks, that's really helpful.:confused:
If I could afford to employ a plumber, I wouldn't be here, now would I?
I'm trying to solve the problem I have, I recognise it, I understand the public health issues - and my conclusion is that there are none, this is not waste or hot water going into a potable supply, or anything like that - I've taken steps to remedy the problem it and ensure that I don't cause any difficulties for my neighbours, and to ensure that my plumbing set-up is acceptable, but it didn't work. I'm trying to figure out what the current weak spot is, and 'I'm not going to deal with your question, go buy another tap' was not helpful.
 
Last edited:
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.
 
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.
 
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?
 
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.)
 
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.
 
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?
 
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.
 
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
 
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.
 

Reply to Check valves and mixer taps in the Plumbing Jobs | The Job-board area at PlumbersForums.net

Creating content since 2001. Untold Media.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock