Leaking galvanised water tank

[Rory]

My Mum's house isn't occupied at the moment and when I went to see her she mentioned that a neighbour had said there was water coming out of the overflow.

So, a bit unprepared, I called in and found water was doing a rapid dribble from the overflow (I was expecting either a drip or it to be hosing out).

I couldn't see much in the loft (only had a small torch from the car) but after removing the insulation it seems that the tank is sitting in (or perhaps it's part of it?) a drip tray and it was the drain from the drip tray that was dribbling outsite. This drain also explains why there were three overflow / warning pipes, which threw me initially.

Seems a great idea having a drip tray, pity that seems to have partially failed too, as some water had gone through the ceiling, although it would have been much worse without it. Are these trays routinely fitted - my house certainly hasn't got one?

I'm not sure of the age of Mum's house - either just before or just after the 2nd WW I would guess. The bathroom and toilet water is fed from the tank (as well the hot, obviously). Is the pipework from the tank (there are two outlet connections) likely to be steel?

[newshound]

First thing to do is to find a way to turn off the supply to that tank, then drain it, probably by running cold water tap in bathroom.

To be honest, if you have a leaking galvanised tank in an attic it is probably well overdue for replacement.

Drip trays are (in my view) a good idea, I now have both a shower pump and a domestic hot water pump mounted in them (after suffering a seal failure). They are not common, especially for big tanks. Sounds like it may have been put in after an earlier leak was patched.

[Andrew Gabriel]

and do this before probing around the tank - it might be very fragile and almost ready to lose a large flake of metal, allowing all the water to gush out.

Make sure the boiler isn't going to fire up if the water supply to a header/vent tank is switched off.

I've only ever seen one, and it was under a hot water cylinder.

[ARWadsworth]

I'll second that I have seen it happen twice.

1st time I was fitting a cable for an electric shower. As I passed the cable up through the ceiling in the airing cupboard I hit the galvanised tank. The bottom of the tank just fell off. That cost me a few quid.

The second was when I replaced a CH system. The tank was drained and as soon as I touched the ballcock it fell off leaving a big hole in the tank.

[Rory]

Thanks for comments. I did turn the water off and drain it - took ages even with hot and cold on. I reckon the tank is 100 gallons. Heating is off too.

I'm fairly sure the drip tray was part of the tank, but whether it really is a tray, or just a lip runing around the base of the tank, I couldn't tell. It had its own drain though, and without it the house would have suffered considerable damage. Pity that it still allowed some water to drip into the house though.

Any idea what the pipework from the tank to the hot/cold will be (house is, I think, between the wars) - would it be steel, copper or even lead?

[newshound]

My guess would be steel. The rising main might be lead, but probably not stuff in the house.

[Nightjar]

Any of the above, although it might be wrought iron, rather than steel, which makes no practical difference. The only way to know for sure is to look.

Colin Bignell

[Rory]

Well, did this job today, as assistant to local to my Mum's house semi- retired plumber.

What I'd described as a tray was actually a sheet of lead laid over a frame, with a drain hole and a lead overflow pipe soldered into it. Frustrating that it had leaked, but couldn't see where.

The old tank just looked horrendous inside, with massive and thick "growths" on the walls. There were at least a couple of rusty spots on the outside, where water had been seeping through.

Apart from the drain for the tray and the tank overflow which were both lead, the plumber reckoned the other pipework was very heavy duty copper.

He'd turned up with a big tank, but it was an inch out from going through the loft hatch. This strikes me as daft - many hatches are probably nominally 2ft square but in reality end up a bit less. Why not make the tanks an inch or two smaller so you'd be sure they'll go in? Then you wouldn't have to faff about with 2 tanks.

He had a heck of a job getting rid of the airlocks from the domestic hot water - that would probably have defeated me without his range of various tubes.