Getting hot water into loft convresion?

mpet

Hi

We've just converted our loft and are adding an ensuite with a bath, hand basin & wc.

Our hot water cylinder is on the floor below (directly underneath out cold water tank. The Hot water system is indirectly fed by the cold water tank. The problem we have is we are not sure if there is enough pressure to get the hot into the loft without a pump. At present there is a 22m air vent pipe that goes from the hot water cylinder up over the top of the cold water tank - basically the same route we want to run the new pipework. If we tee into the hot outlet pipe from the cylinder will it create enough pressure to feed the ensuite into the loft? The height fromthe top of the tank to the loft is no more than 2m.

We have tried attaching a hose to the hot water tap inthe bath room (directly underneath)and leading it into the loft, but nothing come out. If we need a pump has anyone any idea of what sort would be good enough to do the job. (We are OK with the cold)

Thanks
Mpet

ariba10

The water pressure is determined by the difference in the height of the cold water tank and the tap, or shower rose if using a shower.

Three foot would be adequate but the bigger the difference the better.

mpet

The problem we have, is that we cannot raise the cold water tank any higher. I would guess that the tap outlet will the same height as the top of the cold water tank - hence the problem.

We have looked at http://www.grundfos.com/web/homeuk.nsf this pump which from the description may be what we need, but don'twant to buy something like this and find out it wont do the job!

Mpet

ariba10

I have no experience of that type of pump so am unable to advise you.

I know it is of little help but a Combi Boiler would have been ideal.

shockingmoment

mains water pressure is used to feed your header tank. mains pressure is a bar or so - about 10m. the head of water in your header tank is used to provide the pressure to force the hot water out of your hot water tank to your hot water taps. it wont force the water higher than the header tank itself. indeed, as the water level gets close to your header tank - the pressure starts to balance out and the flow rate will slow then stop.

mains pressure is adequate to get to your existing header tank and hence your loft conversion. this will give you cold water for toilet, sink, possibly electric shower, depending on the pressure in the loft. a pump from the hot storage cylinder should be ok. what about a shower booster pump - pumps hot and cold together. combine with a thermostatic tap? hope this helps!
https://www.screwfix.com/app/sfd/cat/cat.jsp?cId=A334831&ts=73520

or this one from your link:
https://www.grundfos.com/web/homeUK.nsf/Webopslag/DMAR-5UHEQJ

don't go for the home boost

BobProperty

I'm not clear on where exactly the tank is, is it in the loft on the floor of the loft?
Three foot will be poor IMHO, and I think you need to seriously reconsider how you are going to get the hot water into the loft bathroom.
The Grundfos pump is a booster for low pressure mains cold water I think anyway.

plumb1_2

http://www.stuartturner.co.uk/products/products.htm

Monsoon N 2.0 bar single high-pressure pump driven by a continuously rated thermally protected induction motor. It is designed to be installed into systems where some or all of the outlets are above the cold water cistern (a negative position) but the requirements is for a fully automatic pump. The N 2.0 bar single is ideally suited as an outlet pump installed between the shower thermostat and control valve. It can also be used to locally boost hot or cold water supplies in both domestic and commercial premises.

WRAS Approval No. 0301060

[FONT=Verdana, Arial, Helvetica, sans-serif]Typical Installation[/FONT]

mpet

Thanks for all your replies - several options to consider!

Bobproperty

The cold water tank is onthe floor in the loft under the lower slopng part of the roof (if that makes sens)- there is noroom to get it any higher.

The link I gave for the original pump did not go to the right link - here is a better description http://www.uk-plumbing.com/product2.asp?name=59539510 - it doesnt actualy say if it is for cold or hot just 'domestic water'

I think I'll give hubby the list and get himto call some of these suppliers.

Mpet

BobProperty

Plumb1 - given that this is for a bathroom, should the OP consider a twin pump (Monsoon N 2.0 twin)? The price of this pump is somewhat different, (about £450 v £300 ) but they can add a shower over the bath. The OP though must consider that the header tank is likely to need to be at least 50 gallon though to go with either pump, so the tank may need to be changed, too.

plumb1_2

BobProperty wrote:

Plumb1 - given that this is for a bathroom, should the OP consider a twin pump (Monsoon N 2.0 twin)? The price of this pump is somewhat different, (about £450 v £300 ) but they can add a shower over the bath. The OP though must consider that the header tank is likely to need to be at least 50 gallon though to go with either pump, so the tank may need to be changed, too.

Hi Bob, I would take it that she has enough pressure on the cold mains to feed the WC and the cold to the sink and Bath/shower. So the single pump should be ok.
You are best to fit a essex/surrey flange into the cylinder to have a dedicated supply to the pump.
If the mains pressure is poor, then i agree a twin booster set would be required, but the CWS tank with have to be up-graded to 50 gall min.

plumb1_2

mpet wrote:

The link I gave for the original pump did not go to the right link - here is a better description http://www.uk-plumbing.com/product2.asp?name=59539510 - i

With you tap/shower outlet being higher than the tanks you need to have a negative pressure pump.