Fitting Shower Pump in Hot Press - Advice Please

magnumlady

Hello my hubby has asked me to post this up to try and get some advice. He wants to fit a shower pump he has just bought (1.5 Bar max) into the hot press and the way he wants to do it for convenience of pipework and space is to put it before the copper hot water cylinder as opposed to after it but he is worried that the pressure out of the pump when it is in operation will push the water up the expansion pipe from the copper cylinder to the cold water storage tank in the loft space. What do you reckon would it?

To explain it better he has drawn (badly sorry) a diagram which I am posting up with this or can be viewed here:

http://www.flickr.com/photos/14692679@N0...
or:
http://tinyurl.com/7q8hb3

Thanks for any helpful advice you can offer if you are a plumber or know a bit about plumbing.

10-10-20

Magnum,

While he's a whizz at drawing diagrams, that's not the recommended method of operation.
The 'pitch pipe' or overflow pipe will allow the water to flow up into the attic tank, instead of into your shower. You will also be pressurising the tank, which is not designed to take this, and you risk a leak or such.

What is his reason for placing both sides of the pump on the cold supply?

311

Surrey flange is what you need.

reg_anam

if your diagram is correct you will definitely get overflow into the tank (normal level in the expansion pipe would be same as cold tank - so little extra pressure is needed to cause overflow. Also ever time the hot taps are used the flow will activate the pump

I think you should consider buying a few flexible connectors to help your layout difficulty and then plumb it the "normal" way !

DEVEREUX

:eek:get a qualified plumber:eek:.for hot the pump has to be fed from an essex flange fitted directly to top of cylinder , or a seperate tapping in the cylinder dome.cold piped directly to pump from tank.if you are just wanting to pump the shower/bath you will also have to get them seperated from the current gravity fed system.

10-10-20

Err - wrong thread...

magnumlady

thanks for the replies so far everyone have passed info onto himself. He has come up with option number 2 (diagram below) of putting the shower pump up in the loft just after the outlets from the cold water storage tank. He knows it says in instructions that there is a risk of pump freezing in the loft space but apart from that would the system work. He knows the pump would come on every time someone runs taps or loo but he said he could wire in a timer to turn it off at night. Doing it the way in option number 2 would this not just mean it would increase the header pressure in the same way that if the cold water storage tank was placed higher up in the loft giving more gravity - so would there be a problem with it coming up the vent pipe then?

thanks again.

Val.

rossie08

Surrey, Essex or Warix flange needed - http://www.buyplumbing.co.uk/VEM-WF15

flange can be got from any good plumbing suppliers like heat merchants or chadwicks

Pete67

magnumlady wrote: »

thanks for the replies so far everyone have passed info onto himself. He has come up with option number 2 (diagram below) of putting the shower pump up in the loft just after the outlets from the cold water storage tank. He knows it says in instructions that there is a risk of pump freezing in the loft space but apart from that would the system work. He knows the pump would come on every time someone runs taps or loo but he said he could wire in a timer to turn it off at night. Doing it the way in option number 2 would this not just mean it would increase the header pressure in the same way that if the cold water storage tank was placed higher up in the loft giving more gravity - so would there be a problem with it coming up the vent pipe then?

thanks again.

Val.

Sorry but this won't work either. The pump will increase the pressure water is supplied to the hot water cylinder at, which is comparable to raising the cold water storage tank. However, you are not raising the vent pipe to cope with the additional head available, so the resulting pressure difference will result in pumping hot water up the vent pipe and heating the cold water tank in the attic.

There are standard designs for implementing a dual shower pump, in this case it is not a good idea to try and re-invent the wheel. The pump should be installed with it's own hot supply from the cylinder, and an independent cold supply from the tank in the attic. Use a suitable flange at the cylinder outlet to get a hot supply for the pump. The pump hot and cold discharge goes directly to the shower mixer tap.

If you can't or are not willing to install it this way then get a professional plumber to do it for you.

magnumlady

Pete67 wrote: »

Sorry but this won't work either. The pump will increase the pressure water is supplied to the hot water cylinder at, which is comparable to raising the cold water storage tank. However, you are not raising the vent pipe to cope with the additional head available, so the resulting pressure difference will result in pumping hot water up the vent pipe and heating the cold water tank in the attic.

There are standard designs for implementing a dual shower pump, in this case it is not a good idea to try and re-invent the wheel. The pump should be installed with it's own hot supply from the cylinder, and an independent cold supply from the tank in the attic. Use a suitable flange at the cylinder outlet to get a hot supply for the pump. The pump hot and cold discharge goes directly to the shower mixer tap.

If you can't or are not willing to install it this way then get a professional plumber to do it for you.

thanks very much for that advice - without the Surrey flange what will be the consequences without it? - air locks or not balanced hot water?

Priced up the surrey flange at local builders merchants but they were out of stock. Its priced at 28.00 Euro. with other plumbing fittings cost is increasing rapidly. Hubby tried phoning 2 plumbers, one the other day said he was too busy and up to his neck in work and wouldn't be able to do it (nice in this current climate of credit crunch) and tried another one today left messages but he never even bothered getting back in touch so hubby thinks he still wants to have a go at fixing himself.

He is wondering now how he would get on without using a surrey or Essex flange to cut down fitting and costs and just using the hot pipe that is already coming out of the top of the copper cylinder that is already feeing the bath tap/shower fitting. we never run any other taps or flush loo anywhere else in the house when someone is having a shower by the way if that has any effect. Thanks.

311

Most importantly a surrey flange prevents air getting into the pump.

Without the flange you'll suck the open vent dry .
It will work without a flange ,but the pump will not last very long without one.
Make sure you get a 22MM flange though ,don't get anything smaller. €28 is cheap enough for a flange

pedroThePirate

311 wrote: »

Most importantly a surrey flange prevents air getting into the pump.

Without the flange you'll suck the open vent dry .
It will work without a flange ,but the pump will not last very long without one.
Make sure you get a 22MM flange though ,don't get anything smaller. €28 is cheap enough for a flange

Yes, you definitely need a Surrey flange.

If the vent pipe is relatively short (eg: in a first-floor
bathroom airing cupboard), would also consider fitting
a non-return valve in the vent to avoid sucking the vent
level down.

cnocbui

I have a 3bar pump and fitted it without a surrey flange and have gotten away with it. It has been running for several years without sucking air or cavitation of the impellers. My overflow pipe is about 3.5m.

I am not recommending not fitting one, as it is best practice to do so, but just thought I would mention not fitting one is not necessarily always going to cause a problem.

If your husband would like a photo of my installation I could provide one. I used my pump to pressurise the entire cold and hot water systems for the house so the advantages of higher flow and pressure are available at every tap/cistern which are fed of the attic tank. Makes a huge lifestyle difference in not having to wait long for sinks or baths to fill and for toilets to re-charge.

sundula

You're a bit late to this one. A UN response to a plumbing problem

sullzz

January 2009 ha ha ha ha