Leaking galvanised steel water tank in loft ??

[AnthonyL]

My wife noticed a slight discolouration on the bathroom ceiling above which is the water tank. We had a survey warning that it looked a bit dodgy when we purchased the house 7yrs ago - it was one of those things "to be done" when we replaced our ageing combi boiler.

Anyhow I've turned the stopcock off to the tank and opened the bathroom tap, filling a number of buckets and draining the rest.

It seems that I have two options unless more are suggested:

1) Replace the tank with a smaller* plastic one

2) Connect the inlet pipe to the outlet pipe and convert the bathroom toilet, bath and sink to high pressure

• The kitchen is now on mains pressure and the bath, if needing extra cold water, is rarely used. A second bathroom with shower is all high pressure. A replacement tank would need to go through the loft hatch

- I'm not sure that the existing one would.

I presume any attempt at somehow lining the tank is a not going to work?

Are either of the options above fraught with difficulty and what should I look out for? Or do I need to get a man in!

[Colin Bignell]

The cistern was probably put in place before the roof was built over it. The main problem with having a mains fed toilet is that it stops working if you lose the water supply. Having it fed from stored water does keep it flushing during a short interruption to the water supply.

[ajh]

I replaced my rusty tank[1] with a same size "coffin" 50 gal tank which fitted through the hatch, I took the opportunity to move it to a corner and give a bit more loft space. I used copper pipe and compression joints to extend the cold feed, expansion pipe and cold water supply and it took about a day of messing around getting the height right with some

4x4. [1] at the thinnest point it was still 1/16" thick as evidenced when I cut it up with a sabre saw to pass it through the hatch. Quicker and less sparks than an angle grinder.

[AnthonyL]

If I replace the tank I'm intending to keep it in the same place. Presumably that will leave me with some fun in lining up holes which will need to be drilled.

[alan_m]

When I replaced a galvanised tank with plastic I up-ended the old tank and just placed the new tank on top of it. I gave a few extra feet of head.

[Vir Campestris]

I was up in the loft of a Lutyens country house once. Leaning against the walls were sections of galvanised iron, and in the middle a rather large plastic tank sitting on a steel support.

On closer inspection the galvanised iron was the original tank, which had been cut up with a gas axe. Then left. I'd have thought the scrap value would have made it worth removing.

Andy

[Tim+]

If you have a “conventional” tank fed hot water cylinder this is a very bad idea.

Tim

[Robert]

+1 But if the CW tank only feeds some taps and WCs then this seems the simplest option. The loss of a Cold Water reserve for WC flushing is probably a risk worth taking unless you are subject to frequent water loss outrages.

[AnthonyL]

Hot Water is from the combi boiler. We've probably had the mains off once, scheduled with warnings, in the 7 yrs or so we've been here.

I guess if going mains some tap washers may need attending to. But it's also nice to think that water can be drawn from a tank without upsetting the flow from the boiler. If it makes any difference the property is a bungalow.

I'll have a closer look tomorrow now that the tank has been drained. It's been boxed in so I need to remove that and the extra insulation that I added last year.

[alan_m]

Not quite true. Once you have drawn a small amount of water from the tank the float on the tank inlet valve will fall and start the tank filling process. You now have mains pressure water going to your combi boiler and at the same time re-filling the loft tank.

[Tim+]

In that case I would definitely ditch the tank.

Maybe, be we’ve been using and old Mira gravity rated shower valve for years since we changed to a mains pressure tank with no problems.

It’s really a case of suck it (or rather “blow it”) and see. Depends a bit on how high your mains pressure is.

Tim

[AlanC]

We had our house switch to mains pressure H/W about a year ago, in preparation for the bathroom refits. We ran with the old toilets and taps for about 4 months. The biggest "problem" was remembering to turn the taps on a little bit otherwise the splash-back soaked your trousers!

[Brian Gaff]

I got a man in and he used two smaller tanks to get them through the loft door, The only problem is that I now have a rusty old tank in the loft which is too big to come out unless its cut up or the roof removed and some kind of scaffolding tower built too remove it. If you already are using high pressure elsewhere, then it might be easier to do the other one the same way, though the Loo filling valve may at present be a low pressure one and it might need to be changed. Brian

[The Natural Philosopher]

Do you have mains pressure *hot|* water already ? I,e a combi or a pressurised DHW tank? If so just do this option.

header tanks unless you live in an area with frequent 'water cuts' are about as senseless as having a diesel generator for electricity.

Pointless. By your own account is is redundant anyway.

Gird thy loins, replace it with some 22mm pass through, cut it into pieces with an angle grinder and take it to the tip

You can then insulate the ceiling where it used to be. Board it over and store some of the accumulated DIY crap you undoubtedly have, take your time and make good the ceiling beneath, and move firmly into the XXI century...

All you need to look out for is plumbing leaks. If soldering copper absolutely do not use lead free solder. It is total pants and will not flow. As I recently discovered. Thank Clapton Ive still got some leaded left over from electronic days. But today if you arm yourself with some pipe cutters and decent wrenches, you can do as good a job using plastic pipe. The plastic connectors are O rings and don't need superhuman force, but connections to existing copper will need well done up compression fittings.

plenty of people here with more experience of plastic plumbing than me. But how hard can it be? Plumbers use it every day...and apart from bricklayers and groundworkers they are the thickest trade there is.

>

[The Natural Philosopher]

If you know the water is going to be off, you fill a bath with cold water and use that with a saucepan to flush your turds away

[alan_m]

Why is a problem being left up there?

[The Natural Philosopher]

Right. Thgat means that tank is completely redundant.

Combi boilers are already way below peak flow rate because they cant heat water fast enough anyway. If you Do The Sums on a DHW water tank at 2.1bar - a normal limit for the tanks - and calculate the actual energy flow of 50°C hot water its gonna be something like 100kW. No domestic bungalow sized combi will match that.

Really mate, rip it out completely and put in some 22mm plastic pipe. Do a temporary bypass first, then pull the tank, and then have a couple of cups of tea and a biscuit and work out what is the best option to routing the new pipe and making everything good.

Allow at least a week, so you don't stress yourself. Even if its only a days work, Then it is really fun.

[The Natural Philosopher]

??? I used bog standard taps and bogs from new with high pressure. My only mistake was not running the shower cold feeds from after the PHW tanks pressure regulator . But the water company has recently dropped pressure in the mains to reduce leakage and its prety damned low these days so it all works

The problem with taps and bogs is LOW pressure - they need bigger pipes and valves to get the flow rates on a header tank only 5 feet over the tap.

[alan_m]

+1 With no hot water tank fed from the cold water storage tank the cheaper and probably the best option would be to put everything on the rising mains water supply.

Note: If you do have a hot water tank tank fed from a loft storage tank then this is a bad idea unless some additional safety components are added and possibly the hot water tank is replaced as well.

[charles]

Anyone like the plumber who used plastic pipe when renewing our utility? We are still living with weeping joints.