Doing away with the cold water tank

We're thinking of converting the loft, and as per most households we have a big cold water tank up there. As far as I can tell the cold water tank only serves the hot water tank. The central heating system is gas powered, albeit a not very recent system. Nothing else uses the tank, so do we really need it? It would be easier doing the groundwork for a loft conversion without it...

Anyone with any knowledge or experience of this?

 

If you got a combi condensing boiler fitted you no longer need the cold water tank as the boiler heats the water off the mains feed.

 

Assuming you have enough mains pressure.

 

The comment about mains pressure is the key.

If you have an old lead mains pipe (15mm) from the street to your house, you could have this replaced (22mm) and this could increase the mains pressure considerably.

This will then give you the options of

1) Combi boiler only providing heating and hot water
This may not be sufficient for your size of house/number of showers/bathrooms etc so you could also try

2) System boiler for central heating plus unvented hot water tank (megaflow or similar) - this uses mains pressure to provde hot water for showers etc - suitbale for houses with 2 to 3 batromms/showers

3) If you want really poweful showers, then you need a shower pump and for this I think you might need a cold water and hot water tank (so called gravity fed which is what you currently have I think).

I'm not plumber but ypu can check out some other useful webistes for further advice:

http://www.ebuild.co.uk/cgi-bin/forums/discus.pl?pg=topics

http://www.diynot.com/pages/pl/

Regards
Kenan

 

Thanks for the replies.
We have an old system, so yes gravity fed I would think. We weren't planning on changing the system as although it's old, it works. But, if this kind of system absolutely must have a cold water tank then I guess we have the choice of either keeping the tank or changing the system! We only have a small terraced 2 bedroom house with a single bathroom (hence the need for another room).

I'll check out the links and then maybe approach a plumber. Thanks guys.

 

get the combi,convert that room.

but make sure that the floor is reinforced to make up for the cut trusses. bouncy hifi ensues otherwise.

 

New combi would cost a fair whack though, we're trying to keep to doing the essentials like the floor strengthening and ventilation etc, whilst trying not to end up borrowing to pay for it. Hmmm.

 

I have a 2 bed terrace, and got a new worcester bosch combi fitted for £1300. If you need to change the system you might need to pay more than that, but gives you an idea of the costs involved.

 

In my house in South Australia we dont have a falling mains fed from a water tank in the loft, all supply is from a rising main. The hot water server is pressurized however. I often wonder why we have such a complicated system in the UK. Central heating is not a problem in SA but we do have an AC for when it gets too hot!!

 

Old Water Board regs used to require an 'air break' between the mains supply and th consumer's enclosed systems to prevent possiblity of back-contamination by siphonage. All changed late 80s when it was finally accepted that (gasp!) a simple back-check valve might suffice.