Cold water tank - external ?

[1Hereward]

Hi all - first post, so please be gentle !

I live in a rural cottage with a private water supply via a borehole and a pressure vessel.
There is not room for a cold water tank in the house as the bedrooms are in the roof space.
We have a fortic type tank upstairs which provides enough pressure for the bathroom which is down stairs.
We would like to put the bathroom upstairs but without a cold tank this is a problem.
My question is can I put a cold water tank outside ? I have a large garden and field sloping up behind the house and could easily situate a 1000 ltr tank (in a suitably insulated house/shed) above the roof height and run it to a normal hot water tank in the house.
If this possible it would solve many problems - we get a lot of power cuts and the rubbish 100 ltr pressure vessel we have runs out very quickly in a house of 4, also they don't last long and it would mean we can have an upstairs bathroom.
Any help / opinions greatly received
Thanks

 

[ianmcd]

not the usuall way but dont really forsee any problems as long as you protect everything from frost damage, just remember that the expansion from the HW cylinder has to terminate higher than the height of the new cold water tank

 

[1Hereward]

Thanks for the reply Ian.
I understand about frost protection etc so would insulate accordingly and make sure all pipework is suitably buried.
I wasn't aware the HW expansion tank had to be higher than the CW tank.
This is going to be difficult as there is nowhere in the house above the new tank outside
Could it be in the same place as the new cold tank ? It would be a lot of pipework but could all go in the same trench.
Thanks for your help

 

[ianmcd]

its not a tank it is a pipe that comes off the top of the HW cylinder and must rise continuously and terminate above the level of the water in the cold water tank feeding it, the pipe cant go downwards as it is there as a safety to allow expansion releif if the heat source cut out thermostat etc should fail

 

[1Hereward]

Should it terminate outside of the house then ?
How are they normally discharged ? Onto a roof or something....
Thanks for the help.

 

[ianmcd]

Depending on the height that your proposed new cold water tank will be from the height of the proposed upstairs bathroom it might be possible to have an unvented HW cylinder installed, I have never seen one that was storage fed as they are usually mains fed, you might be back to square one with a booster pump though if you dont have enough head of water, in order to install an unvented cylinder you need to have a qualification called G3 and you must notify your local building control so not sure if you would get permission to install one the way you propose you can only ask the question

 

[1Hereward]

I think the easiest way would be to have the expansion as you suggest.
Can it go out the roof and up the soil pipe to get the height ?!!

 

[SimonH2]

Depending on the height that your proposed new cold water tank will be from the height of the proposed upstairs bathroom it might be possible to have an unvented HW cylinder installed, I have never seen one that was storage fed as they are usually mains fed, you might be back to square one with a booster pump though if you dont have enough head of water, in order to install an unvented cylinder you need to have a qualification called G3 and you must notify your local building control so not sure if you would get permission to install one the way you propose you can only ask the question

I can see no reason it couldn't be done - after all, it's no different to the public water supply in most places (ie reservoirs and some piping to the customer).

If an unvented is not an option (might be in terms of installation requirements, not because it's off a header tank), then a thermal store might be - integral F&E tank can be directly on top of cylinder, while water supply is separate. Cue wails from the "would never fit one of those if it were the last option" types

Or what rating is the pump ? Would a UPS or separate (perhaps lower capacity) DC pump and batteries be an option ? No plumbing changes that way.

I think the easiest way would be to have the expansion as you suggest.
Can it go out the roof and up the soil pipe to get the height ?!!

I wouldn't have thought so - it'll be very prone to freezing, and then it mights as well not be there.

EDIT: I used to work on a farm with a header tank like that. Borehole pump, tank on top of the hill. But I assume they probably had a conventional header tank in the loft as that was an empty space there.

 

[Norcon]

Our old farm had the tank in an out building and the vent just went straight out through the slated roof.
Pump down the field from a hand dug well. It all worked tickity boo.

I'm sure there was times when the vent was froze solid.

 

[1Hereward]

thanks for all the replies - seems its feasible - just need to work out this expansion / vent business.
How should it be done ? Whats the correct method ?

 

[Agile]

I would suggest a Grundfos home booster pump set.

A bit more expensive but it stores about 200 li of water and delivers about 2-3 bar of pressure. Thast when you have got mains to operate the pump.

If you have such frequent power cuts then you should get a generator!

Tony