Moving hot water tank to loft ??

In therory it is do-able. Weight and wall loadings is the major consideration. Also the roof must be strong enough to take the massive weight of a water tank  - it must be floor supported, NOT hung off the roof beams. Is you loft opening wide enough?

Better still fit an unvented cylinder in the loft then there is no need for a storgae tank.....or just fit a combi boiler?

 

Is an unvented cylinder just 1 tank that has the cold ontop ......  NO

Or is it worth fitting a pressurised tank (megaflo) ........ THAT IS AN UNVENTED CYLINDER.
There are important safety features incorporated into an unvented cylinder. Normally fitted by special peepol who carry a certain G3 tkt.

 

I have often moved CWS tanks into the loft in order to free up space and also improving the static head for the hot water.
However, moving the hot water cylinder up there as well is a bit of an unproffesional thing to do (think I've done it once in 40 years of plumbing), loss of the static head being the main reason not to along with a host of others.
I don't think it's a job for a diy either.
Tappy,

 

You'd need to raise the cold water storage tank above the vented cylinder and it would probably still suck air in down the open vent when you drew off hot water. I wouldn't do it.

 

Cheapest option is as Brownose advised is a Combi Boiler,why dont you consider this. Fit in the roof space if you can.

 

You're right, Duncan.

You can get powerful combis which are reckoned to handle more than one hot water outlet at a time, but it does depend on you having very solid mains water pressure and flow first. Since you've tried a combi before and found it wanting, then you are the best judge of whetehr it's suitable for your current home. It's certainly the most space-saving solution, tho'!

(Mind you, modern combis are pretty effective and can give decent flow rates - can you remeber what model you had in your last home?)

 

But they can't perform miracles. If the cold water flow rate is 10 litres/min you can fit the biggest combi there is and the flow rate will still be 10 litres/min.

Mains connected unvented cylinders can have the same problems as a combi for the simple reason that both are taking water directly from the mains; it doesn't matter that the cylinder has 200 litres in it. The only reason water comes out of the tap is that the mains pressure is putting water into the cylinder. So the flow rate will be dictated by the cold water flow rate and pressure. The only advantage of a mains connected unvented cylinder is that you do  not have to heat the water instantaneously, so the boiler can be much smaller.

 

Cheers, Mr Spade. I did, for that reason, qualify my comment with "...but it does depend on you having very solid mains water pressure and flow first."

I did wonder if the same thing applied to 'megalflow' units - it made sense that they were governed by mains water flow, so cheers for confimring that. In which case, why are some plumbers on here praising them from the rooftops?

When you consider their extra expense, the extra room they take up, the need for a particularly qualified peep to instal it, the additional running cost from having stored hot water, and finally the pitiful extra gain in performance for the vast majority of us, why would peeps choose them instead of a powerful combi?

I wouldn't.

Oh, I haven't...

(Ok, 'powerful' is pushing it a bit, but hey...)

 

Just go back to Browns and Wetpants comments, its already been said ***

 

DA.....an unvented cylinder delivers balanced supplies to multiple outlets....it does not go cold when someone runs another tap. Of course they have flow/pressure requirements but if the install is in spec they are simply superb.

 

In theory  - yes.

In practice ( weight, loading, sufficient head, venting ) maybe no.

Without seeing and measuring it is impossible to say.

You hot water cylinder should be insulated anyway! If its an old one it will be damaged when you move it.

 

Duncan, in theory and practice, yes. Provided you can give your cold tank good head and all the stuff GB says above.

With a vented system - such as you currently have - it is essentially the CWS wot provides the water pressure and flow to the taps. In theory raising the hot cylinder shouldn't affect this at all. However, raising the hot cyclinder closer to the CWS tank level can cause other problems as outlined by Onetap above - if the CWS isn't providing good head to the hot tank, then there is a risk that when you draw off hat water - which comes from the top of the hot tank - it will instead (or also) draw in air from the expansion pipe wot is also exiting from the top of the hot tank and looping over the CWS. This is because the CWS isn't positioned high enough above the hot tank so isn't delivering enough pressure to the hot tank.

Bottom line - how lofty is it up in your loft? If you place your hot cylinder on the floor up there, can you then lift the CWS a good few feet above the top of this tank?

I don't know what a "good few feet" means in practice - hopefully a plumber on here will give that info. But, as Onetap suggests, if you asked a plumber to do what you suggest they might well be reluctant to do so cause if it starts drawing in air when you run the hot taps, they'll be the ones getting into hot water.

And if you ever fit a pump to the system to provide a better shower, then the problem is magnified.

So, afaIk, it all comes down to how high you can get the bottom of the CWS above the top of the hot cylinder.

You should also be looking at positioning the hot cylinder above a supporting wall in the floors below - a CWS is bludy heavy; a hot cylinder more so.

 

If your attic has a steep pitch, then fair chance you'll be able to make it work - tho' a pro on here (or a plumber you contact) would really have to confirm what sort of height is needed.

I think fitting your CWS higher will be the least of the tasks - you can get long 'coffin' tanks that you can squeeze right up into the appex of your roof - supports will be taken from joists spanning the rafters and supported by a few uprights. Because the tanks are long, the weight is distributed, so rafters ain't gonna feel it*. That's realatively easy. You can fit a number of tanks, all linked together. Making sure your hot cylinder - wot has a small footprint and will therefore rerquire much more localised support - is secure is another matter, tho' not rocket science.

What do you mean by "Are hot water cylinders with a separate gas boiler a good system for quite a large house...?" . Isn't that what you've got? Is it not running at present? To answer your Q, yes, it's a good system for a large house as the cold and hot supplies are taken from different connectors on the CWS so won;t affect eachother. As long as your mains water supply is up to replenishing the CWS, then you can in theory draw as much water from as many outlets as you want. All things being relative. You can add a pump to give a power shower, etc.

Have you had your mains water pressure and flow measured? You can do a basic test yourself - stick a bucket under your kicthen tap, turn it on full for 10 seconds, and measure how much water is in there. Times that quant by 6 to get litres-per-minute. (Or you can do it for only 10 seconds if you wish, of course...) What do you get?


*That's what I think anyways...