Is there such a think as a water pipe non return valve?

[Phild1]

Hi, I have a shower coming from a bath mixer tap. Because the hot water is such low pressure I fitted a pump to the hot wter tank - this works fine. The problem is, the pressure of the hot water far outweighs that of the cold and if you shower for anything longer than few minutes the hot pushes the cold back up the pipe, fills the tank and water starts shooting out the side of the house! I am waiting for a quote for a plumber to fit a pump that will work for hot and cold thus equalising the pressures but I was just wondering, is there a fitting that will stop the cold water reversing as this would be much cheaper than a new pump? I have googled this but am confused as some say they are for air only and I am not sure about sizes. Any advice would be great. Thanks in advance. Happy Easter to all!

 

[Ric2013]

Yes, it's called a non-return valve, or a check valve, for backflow protection. But if your hot pressure far outweighs the cold then fitting one will not really solve your problem in that although it would prevent the backflow, you might still experience poor performance from the mixer without the pressures being roughly equalised.

 

[Phild1]

Hi,
thank you for the information, much appreciated. I had a plumber round and he recommended putting in a better pump and run hot and cold through so they both equalise. I just wondered about the valve as the new pump plus installation isnt cheap so it may be worth trying the valve first. Thanks again for your time.

 

[Gerald]

Hi, I have a shower coming from a bath mixer tap. Because the hot water is such low pressure I fitted a pump to the hot wter tank - this works fine. The problem is, the pressure of the hot water far outweighs that of the cold and if you shower for anything longer than few minutes the hot pushes the cold back up the pipe, fills the tank and water starts shooting out the side of the house! I am waiting for a quote for a plumber to fit a pump that will work for hot and cold thus equalising the pressures but I was just wondering, is there a fitting that will stop the cold water reversing as this would be much cheaper than a new pump? I have googled this but am confused as some say they are for air only and I am not sure about sizes. Any advice would be great. Thanks in advance. Happy Easter to all!

Fit a pressure equalising valve. It will automatically adjust the highest pressure down to match the lower one.
Altecnic GR5531002 is one that will do the job.

 

[GerryS]

You need a pressure equalising valve that will automatic adjust the highest pressure down to match the lower one. An Altecnic GR5531002 is a good one.

 

[Phild1]

Altecnic GR5531002

Thank you - I will have a look.

 

[EvilDrPorkChop]

Your plumber is right, you need to pump cold and hot supplies. Otherwise it'll never work. Non Return valves aren't your answer.

Rather than a pump you might want to invest in updating your system to an Unvented hot water system, or combi boiler. Personally I always think pumps are a waste of money when it could be put towards one of the above systems.

 

[MARTIN STANJER]

using of pressure equalizing valve will take you out from this trouble. Because it will equal the pressure of hot and cold water, no matter what's the difference between hot and cold water pressure.

Equalising the pressure is ok, but if Phil's cold is also supplied from a tank in the loft (same as the hot) then he'll be more or less back to where he was without the pump! Ok if the cold is on the higher pressure mains of course, but if this is the case I'm surprised that the cold isn't still at a similar or higher pressure than the pump is supplying to the hot. (If mains pressure is low, a mains pressure booster from salamander or grunfos might benefit the whole house.)

 

[Phild1]

Hi and thanks for all answers. Yes the cold comes from a tank in the loft so the pump does increase just the hot water, hence it pushing the cold back up to the tank then fills the tank which then pours outside. Equalising to the lowest pressure would be pointless - I might as well just turn the pump off. Which if I do, results in a trickle of a shower. I think a good pump on hot and cold as the plumber suggested, might be the only answer.

 

[Phild1]

After some thought I think I might go for the house pump which will equalize the hot and cold to the showers and boost the hot throughout the house - this seems ideal. I know this is a difficult question to answer but how much should I look to be paying in total, for both the pump and the work? I ask as I have had a quote and it seems very expensive. But I have no reference so any ballpark figures would help. There are two showers to boost and there is space next to the hot water tank for the pump to sit. Thank you.

 

[EvilDrPorkChop]

After some thought I think I might go for the house pump which will equalize the hot and cold to the showers and boost the hot throughout the house - this seems ideal. I know this is a difficult question to answer but how much should I look to be paying in total, for both the pump and the work? I ask as I have had a quote and it seems very expensive. But I have no reference so any ballpark figures would help. There are two showers to boost and there is space next to the hot water tank for the pump to sit. Thank you.

How much have you been quoted?

 

[Phild1]

How much have you been quoted?

750

 

[Phild1]

meant to add it is a 2.0 bar whole house pump which I was told would be ample in pressure.

 

[EvilDrPorkChop]

You will have to be aware every time you run a hot tap the pump will run. It can be quite annoying.

Personally i'd chuck the 750 towards an Unvented cylinder. The better all round solution if it's possible.

But the £750 doesn't sound unreasonable. There's probably £200/300 in the pump at least.

 

[Phild1]

Thanks for the reply. I just had a new boiler installed 18 months ago so replacing it seems a bit of a waste. You are right about the pump - £250 - £380 is the range he is also going to replace two plugholes for clickers and tidy up some pipe work so I guess if you add that to you thinking the price isnt unreasonable then it makes it more than ok. I am getting a second quote tomorrow so I'll see how that pans out but the first guy has a very good rep. Thanks again.

 

[EvilDrPorkChop]

Y

Thanks for the reply. I just had a new boiler installed 18 months ago so replacing it seems a bit of a waste. You are right about the pump - £250 - £380 is the range he is also going to replace two plugholes for clickers and tidy up some pipe work so I guess if you add that to you thinking the price isnt unreasonable then it makes it more than ok. I am getting a second quote tomorrow so I'll see how that pans out but the first guy has a very good rep. Thanks again.

You wouldn't need to replace your boiler. You can just replace the hot water cylinder and the boiler would stay existing.

 

[Ric2013]

Seems not unreasonable price, if you want to take that route. Last shower pump I fitted was in an airing cupboard to an existing shower (shower was already plumbed back to the cylinder - badly). So fit pump, modify cylinder connexions, new cold from the cistern in loft, and patch up existing pipework ended up taking 2 very long days and an hour. Had I not already provided a fixed-price quotation for the job, I'd have been charging for three days' labour and, of course, the pump and fittings (especially if the installer is providing Y strainers to protect the pump) will not be cheap.

 

[Phild1]

Thanks for that. What you say is very helpful. I think I am going to go with the original plumber and the pump. Thanks again for your help.