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https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl DIY Forum >> Plumbing Questions >> Hot water tank platform https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1609534737 Message started by Natedog on Jan 1^st, 2021, 8:58pm

Title: Hot water tank platform
Post by Natedog on Jan 1^st, 2021, 8:58pm

I'm tidying out our loft. One job that I want to do, but don't know what to do is sort out our water tank location. Currently they're sat on a pile of wonky pallets, not even vaguely level. I'm assuming this was done to add a bit of extra head to the hot water for the shower? The hot water pressure here isn't brilliant, so I don't want to make it any lower - if anything it wants raising up more.

How would I go about raising the tanks properly? There's a smaller header for the heating and a larger (90 gal?) for the hot water

To make it more fun, the loft hatch is only 21" square

Title: Re: Hot water tank platform
Post by woodsmith on Jan 2^nd, 2021, 7:57am

Usually you can make a supporting frame from 3x2, and t&g softwood flooring for the platform. Make sure you spread the frame at least one ceiling joist beyond the large tank to spread the load across the ceiling. The only caveat is you need to ensure the ceiling joists can take the load, it’s normally not a problem. I’d screw everything together rather than nail it and stay slim!

Title: Re: Hot water tank platform
Post by thescruff on Jan 2^nd, 2021, 10:31am

As above spread the load by screwing a plate over as many joists as practical, use screws because it's easy to damage the ceiling if you go baning around.

Use wood as other materials will rot if it gets wet.

Important.

The top of the heating tank should be at the same level as the storage tank.

Title: Re: Hot water tank platform
Post by Natedog on Jan 2^nd, 2021, 11:42pm

[gallery fullsize]Natedog/1609630449.jpg[/gallery]

Ive had a think, and this is what I've come up with. Hopefully this makes sense...

4x2 secured to the chimney breast. I'm guessing something like 4" number 10 screws for added overkill. Then on top of that I've got lengths of 4x2 at 14" centres with a ¾ ply top (I've got a sheet spare, could double this if needed to make 1½ thick)
The front of these is supported by a 4x2 running parallel with the chimney wall. At either end, a 4x4 leg made from 2 lengths of 4x2 glued together, fixed with a bridle joint, glued and screwed from both sides.

The legs rest on a 4x2 which sits on 3 joists. There is a supporting wall more or less dead centre under the tanks, and its not going to be very different in weight to what is already there.

I think I'd also probably add a couple of triangle blocks to the bottom of the legs to hold them vertical.

Does that sound the sort of thing? Anything I've missed?

Cheers

Title: Re: Hot water tank platform
Post by Natedog on Jan 3^rd, 2021, 12:27am

thescruff wrote on Jan 2^nd, 2021, 10:31am:

Important.

The top of the heating tank should be at the same level as the storage tank.

The header tank for the heating is roughly half as tall as the tank that feeds the hot water. Does this mean it needs to be sat on its own little platform to raise it up? If so, what is the reason for this? It is currently sat on the same platform as the other tank

Cheers

Title: Re: Hot water tank platform
Post by woodsmith on Jan 3^rd, 2021, 9:12am

I don’t think you need 4x4 legs, 4x2 is ample. Personally I wouldn’t screw it to the chimney, I’d build a complete frame, 4 legs with diagonal bracing, and I wouldn’t use ply even if I could get it through my small hatch.

Title: Re: Hot water tank platform
Post by Natedog on Jan 3^rd, 2021, 11:22am

I had actually forgotten.about needing to get it through the hatch 🤣

Title: Re: Hot water tank platform
Post by Natedog on Jan 3^rd, 2021, 3:58pm

One last question - I was planning to replace the tanks at the same time. The lid on the larger tank has cracked and the smaller one has a huge corner cut off it for the overflow pipe, rather than a small neat hole with a seal.

The tanks that are there are this style, sort of flimsy plastic
https://www.toolstation.com/water-storage-tank/p38349

But I can't find them in larger sizes. Everyone seems to be stocking this sort https://www.toolstation.com/25-gallon-polytank-blue-water-storage-tank/p91853

They do look much more rigid, are they now what you're required to fit?

Title: Re: Hot water tank platform
Post by thescruff on Jan 3^rd, 2021, 9:03pm

Yes the water in the small header tank should be level with the domestic storage tank. the reason being if something does wrong with the cylinder the higher level can flood into the lower tank.

Toolstation do a similar tank 42Gallons which is much better.

Consider making a bigger hatch whilst you are playing, it really is a simple job.

Title: Re: Hot water tank platform
Post by Natedog on Jan 3^rd, 2021, 11:28pm

Theyve only got the 25 gallon in stock locally or for delivery

thescruff wrote on Jan 3^rd, 2021, 9:03pm:

Consider making a bigger hatch whilst you are playing, it really is a simple job.

That takes all the sport out of it 😆
Seriously though, short of moving the hatch to a different room, it is as big as it can be due to the layout. Walls in the way on 2 sides and timber frame for the roof and the landing light in the way on the other 2.

Title: Re: Hot water tank platform
Post by thescruff on Jan 4^th, 2021, 12:18pm

you can always connect two together.

Ballvalve in one end tank and the outlet in the end off the other tank so you get a flow through with no static water

Title: Re: Hot water tank platform
Post by CWatters on Jan 5^th, 2021, 6:05pm

woodsmith wrote on Jan 3^rd, 2021, 9:12am:

+1

Take the load down to the joists rather than rely on screws into the chimney.

Title: Re: Hot water tank platform
Post by Natedog on Jan 6^th, 2021, 3:22pm

8ve gone with the 25 gallon, and ill see how that does. The kids have moved out now, so as long as it can keep up with the shower it should be fine.

I've just been furloughed, so hoping to crack on with it and get it all done this week.

I've got some of the large pile of crap moved out the way so I can remove the old insulation and rubble. I can now see the chimney isn't actually flat at the height the platform is going to be at, so probably not practical to mount it to the chimney anyway.

The one end of the stack of pallets is barely an inch onto the timber supporting it, and there's only 2 slats touching it. No wonder it has started to lean!

Title: Re: Hot water tank platform
Post by Natedog on Jan 20^th, 2021, 4:59pm

All done and not leaking ;D

I'll take a photo to show you what i've done once i've finished tidying up. I did forget about the heating header needing to be raised up a bit, but that can wait until another day. i'll need to drain the system again to swap some radiators so i'll raise the header at the same time. I need to crack on with a few other little jobs before they call me back to work.

Thanks again for your help, it is very much appreciated :)

Title: Re: Hot water tank platform
Post by woodsmith on Jan 21^st, 2021, 9:02am

Glad you got it sorted and it gave you something worthwhile to do in these strange times :D

Title: Re: Hot water tank platform
Post by Natedog on Jan 25^th, 2021, 3:33pm

[gallery]Natedog/1611588204.jpg[/gallery]

[gallery]Natedog/1611588336.jpg[/gallery]

[gallery]Natedog/1611588350.jpg[/gallery]

Yes, I know its hugely over-engineered, but I went with using wood that I had kicking about in the workshop where I could. But it can quite happily take 18 stone of me jumping up and down on it, so I'm confident its going to support the tanks ok ;D

I still need to tweak the vent pipe slightly - I ran out of new 22mm and the re-used stuff is a bit crusty inside. It could also do with being a touch higher as it does dribble ever so slightly when the pump changes speed, but the tank doesn't get warm like it used to from the constant flow out the vent.

Just got to sweep up and cart all my tools back down now

Thanks again for you help ;D

Title: Re: Hot water tank platform
Post by thescruff on Jan 25^th, 2021, 4:25pm

Good job, the vent pipe needs lagging as well.

Talking vent pipe if there's a dribble into the tank it almost certainly points to a future problem.

Follow it down where it connects into the heating pipe (by the cylinder) I assume and post a pic, please.

Title: Re: Hot water tank platform
Post by Natedog on Jan 25^th, 2021, 4:53pm

[gallery]Natedog/1611593131.jpg[/gallery]

it's not so easy to see which pipes go where, and it's kinda tight for taking a decent pic, so i've marked up the pipes as best as i can below

[gallery]Natedog/1611593241.jpg[/gallery]

red - from boiler
blue - return to boiler
purple - to radiators
yellow - 15mm from header tank
white - vent pipe

the vent tees off the pipe from the boiler under the floor
the fill from the tank joins the same pipe just in front of the pump

new years eve 2019 the pump failed, and nowhere was open who had a matching pump (standard old grundfos thing) so it was swapped for this posh one that maintains constant pressure, speeding up or slowing down as the TRVs open and close.

I don't know if it's relevant or not, but when the cylinder was changed about 10 years ago, the pipework coming from the syslinder was slightly modified. originally the blue pipe coming from the cylinder was reduced down to 15mm for about 8 inches, then back to 22. i had to cut the pipes to get the cylinder out, and it was replaced with 22 as that's all I had

don't know if it's related, but when the boiler is on doing hot water only, the landing and bathroom radiators get slightly warm, but the water is flowing the wrong way (lockshield end gets warm first, not the TRV end as it does when the heating is on.

At some point in the near future, the whole lot will be being ripped out again, as i want to fit a solar hot water system as well, so will need to put a twin coil cylinder in

Title: Re: Hot water tank platform
Post by thescruff on Jan 26^th, 2021, 10:15am

You're obviously getting a backflow which doesn't help but difficult to see from the pic.

The only thing I note is the cold feed and vent connection should be as close as possible with nothing between them.

Any chance of a simple line drawing showing the boiler flow and return and any connections

Title: Re: Hot water tank platform
Post by Natedog on Jan 26^th, 2021, 9:27pm

[gallery]Natedog/1611695484.jpg[/gallery]

I think that there may be more than 1 return connection for the rads which is causing the back flow when its on hot water only, but that will be under the floor somewhere

Fill is closest to the pump, probably about 3 inches from it. The vent is gonna be another 8 inch past that at a guess.

Pump is a grundfos ups3 15-50/65 130

The valve (tower mid position valve) is getting tired and makes some odd noises when it switches on

https://youtu.be/jTiJsEHCQnU

First putting it on heating only, then the screaming noise is it going to hot water only

Title: Re: Hot water tank platform
Post by thescruff on Jan 27^th, 2021, 9:54am

Looks good actually, the connection for the cold feed and vent should be as close as possible if I was being picky.

The 3port may be leaking heat into a couple of rads if it's worn but that wouldn't reverse the circulation so, as you say a wrong connection under the floor.

Title: Re: Hot water tank platform
Post by Natedog on Jan 27^th, 2021, 11:38am

If its not a daft question, why isn't the fill and vent done as 1 pipe?

Title: Re: Hot water tank platform
Post by thescruff on Jan 27^th, 2021, 2:04pm

Used to be frowned upon by British gas in the good old days.

Nowadays it's done for low head systems but it makes filling a pain in most cases

Title: Re: Hot water tank platform
Post by Natedog on Jan 27^th, 2021, 2:51pm

Filling ours is a pain anyway. I can still hear air moving about somewhere after a week

Title: Re: Hot water tank platform
Post by thescruff on Jan 27^th, 2021, 7:43pm

There should be an air vent at the highest point where the flow leaves the cylinder, I assumed it was out of frame.

Title: Re: Hot water tank platform
Post by Natedog on Jan 29^th, 2021, 10:51pm

There is an air vent pipe on the pump side of the cylinder. Its the pipe you can see sticking up in the first pic, with the compression fitting on it.

We were having problems with air getting in to the system, so I extended the pipe with the vent on, so it would be able to collect more air and not need bleeding every single day. It has since been traved and sorted (pin holes in a rad, replaced rad and it stopped) so could really be shortened again. I just haven't got round to it

Title: Re: Hot water tank platform
Post by thescruff on Jan 30^th, 2021, 12:19pm

Don't shorten it.

Better still hole a glass of water under the vent pipe and get someone to turn the boiler on. with and without the heating on.

Does it suck the water out of the glass?

Title: Re: Hot water tank platform
Post by Natedog on Jan 31^st, 2021, 10:12am

I should have called that an air bleed, not an air vent. Sorry! The air in the system problem went away after replacing a couple of pinholed rads and replacing some elderly TRVs

I'll try the glass under the vent next weekend. Won't have time before I'm back to work later today

Title: Re: Hot water tank platform
Post by thescruff on Jan 31^st, 2021, 10:52am

The air could be caused by corrosion if you have a couple of rads pinholeing, , in which case after you have finished the work make sure you put an inhibitor in the system.

Check behind the radiators with a mirror to make sure there's no serious corrosion on the bottoms of the rads first.

Title: Re: Hot water tank platform
Post by Natedog on Jan 31^st, 2021, 12:20pm

when the heating was installed, her ex-husband did it on the cheap. there was a handful of rads that were 2nd hand as they were "the right price" (presumably free) i've replaced 8 out of the 11 rads over the last few years as i've been decorating. i hate brush painted rads, so the ones that were looking scruffy just got changed. they're cheap enough that i don't think it's worth the hassle of removing them to spray them.

and yes, one i had run the cleaner through and flushed the system out a few times, it did get refilled with 2 bottles of F1 in it

Title: Re: Hot water tank platform
Post by thescruff on Jan 31^st, 2021, 9:54pm

toolstation radiator are cheap as chips at the moment.

Recently got 9 48 x 24 double panel with fins for around £56.00 including valves

Title: Re: Hot water tank platform
Post by Natedog on Jan 31^st, 2021, 11:18pm

I get whatever the closest size is in their clearance range. The landing radiator got replaced with a 500x1800 single panel which cost me £18. For that money I wasn't worried about modifying the pipework a bit

Title: Re: Hot water tank platform
Post by thescruff on Feb 1^st, 2021, 9:18am

Good price.

Has Danny contacted you?

Title: Re: Hot water tank platform
Post by Natedog on Feb 1^st, 2021, 11:39am

Yes thanks ;D