Where to put water tank - loft or.....?

Sep 21, 2021 Last reply: 4 years ago 30 Replies

My ex is starting building works on her house in the Irish Republic. Regs say a house has to have a water tank. Right now it's located in the loft. The builder wants to put it on the ground floor with a pump, saying it should be next to or near the water heater.



What's the right thing to do here?


Not really sure why the proximity to a water heater matters - assuming it's a cold water header tank?

Loft is usual, because it gives you the maximum 'free' head. And there is likely more room up there than on the ground floor where cupboard space may be at a premium.

I'm often a bit wary of what a builder says. Often just the easiest for them.

More info required. Hard to see how it can be a header tank on the ground floor (assuming there are services in the first floor). Do Irish regs require houses to have a store of drinking water? "Close to heater" may be suggesting a location that minimises pipe runs?

Sounds like some confusion. If it's a /pressurised/ hot water system, then the hot water tank would indeed be near the 'water heater' aka boiler, and there would be no header tank.

However, you'd probably not need a pump.

Too many unknowns, more info required.

Perhaps you should ask the builder to explain why he thinks a cold water tank should be near the water heater.

If the cold watertank is low in the roof and your ex wants a power shower upstairs then a shower pump may be appropriate.

Ah, do Irish building regs not allow a house to have a mains-pressure hot-water system (cylinder or combi)? Must the hot water always be fed from a low-pressure header tank?

If its a pressurised system it can go *anywhere*.. Being close to the boiler is only to minimise primary circuit losses, but they are dwarfed by losses from the tank itself in most installations

Mine is on the loft because there was space there. Boiler is two floors down on ground floor.

I take your mentioning that the regs require this tank to indicate clearly that it is the cold water tank for everywhere bar the kitchen sink.

I think it would be reasonable to ask the builder to explain the pros and cons of that as against a tank in the loft. FWLIW it seems to me have the big "con" that a power cut would mean no cold water for loos.

PS

I've no knowledge of Ireland's legislation but from a very quick look at Technical Guidance Document G see that clearly envisages that the cold water tank /may/ be in the attic - but does not mandate that it /must/ be there.

newshound explained on 21/09/2021 :

!With a pump!..

Does the pump feed a mini header tank in the loft, or does it just dump whatever its output pressure is into whatever it is feeding.

Most houses had stored cold water at one time. Potable fresh direct from the mains being restricted to the kitchen tap.

In those days bottled water was rare, and stored cold OK if boiled to make tea, etc. Or for washing.

I've been used to houses where the hot is pressurised from the cold header tank and all the cold taps direct from the mains. In the event of the water being cut off for a while, cold would have to be obtained from the shower (as the only gravity fed cold supply) and then boiled.

Yes, that makes sense, though closer sounds better, the cylinders are very well insulated.

Whatever regs say, I wouldn't fancy a pressurised hot water cylinder in the loft! Is that common?

How large is the tank and how much space would it take up if sited away from the loft.

My loft tank contains enough water to fill a bath.

I would always work on deleting any loft tank in any house I lived in.

Depends whether you might need it in empower cut I'd imagine. Brian

No idea. I sleep under it. It has full safety valves and overpressure stuff, Done so for 20 years.

I've seen others in the 'boiler cupboard'. But the other issues are:

(1) weight. Loft needs to be able to take weight of a tank., 250 liter tank is about 320kg

(2) distance to hot water taps/showers. The shorter it is the more instant it is.

My loft tank contains enough water to fill at least one bath and most of another one. 250l is a nice size - about 5 ft tall and 2 ft diameter

Most tanks are less than 6ft tall, and are around that sort of footprint - will fit into 600mm standard sized spaces

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My policy is to place the hot tank as close as possible to the taps, and ideally the boiler. It's good to minimise loss where you can.

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