Any Plumbers Or Handymen On Here For A Bit Of Advice Please.

[saintpeter48]

I have an immersion tank in my airing cupboard, a 'Gledhill Envirofoam Copper', fitted three years ago, lately there have been traces of water dripping slightly at the bottom of it, I've looked and felt around it but can't seem to notice where its coming from, I've traced it to the top, the tank has a black lid at the top and when removed it exposes the water and stop cock, it seems that condensation builds up on the inside of the black lid when the water gets hot, the condensation then seems to be running down the sides of the tank and this is where the dripping is coming from. My question is this, Is this a common problem, should I remove the lid altogether or should I make sure the lid is fitted tighter to the top of the tank to stop the condensation dripping over the top.
Any help is much appreciated, thanks.

[malagabob]

Assuming you’ve narrowed it down and are confident the cause of the drip is coming from the tank. Is it insulated. Tank sides and lid. A tight fit is important. ( lid not protruding on any side/back ) Is the tank high up to a ceiling. Any condensation there.?

[saintpeter48]

The tank is a self insulated one, foam fitted.
I'm pretty certain that it is the lid where the water is coming from, it wasn't fitted tightly when I checked, I did remove it and there was a large, (about 2 inch) hole in it with a plastic sort of nut, which when removed leaves a hole for steam to escape I assume, I removed this and fitted the lid to the tank as firmly as I could, I will check later to see if it has made any difference.

[saintpeter48]

Tank is not high up and there is no condensation on the ceiling.

[The Builder]

St Peter, it sounds like you have what used to be called a "Fortic" cylinder.
Conventional immersion cylinder with a separate cold tank fixed on top. (A "combination cylinder".)

Water vapour will go out through the built-in expansion pipe from the cylinder to the top storage part.
Although the water in the top part will get a bit warm from where it sits, the lid will probably remain cold. Thus the vapour condenses on the underside of the lid.

Essential to keep the lid as tight fitting as possible. Then, any condensation will fall harmlessly into the cold storage.
I'm pretty sure that's all it is.

[bluemoon1]

Why do you need the lid? It's a while since I was a heating engineer but when we fitted cylinders and header tanks they never needed a lid. I'd be interested to know what the reason is nowadays.

[1ozzy]

bluemoon1

Possibly to stop unwanted creatures, dust, dirt and anything else that you wouldn't want getting into your hot water supply getting in there.
Just a guess

[10ClarionSt]

My header tank doesn't have a lid. It never has, and we've been here for 42 years. No harm done yet, he said, tempting fate!

[david small]

My header tank had a lid but never had condensation problems. Everything else though. I got rid of after years of hassle.

[bhg481]

The lid on the tank has two purposes. First it keeps foreign bodies out of the tank the supplies the water that most people clean their teeth with and perhaps get in their mouth when they shower. (I've heard of dead mice and small birds being found in the tank). Second it helps retain the small amount of heat in the tank which helps to prevent it freezing. The tank relies on heat from the airing cupboard to prevent it freezing. In the good old days hot water cylinders weren't lagged so thee was always a good supply of heat. Nowadays there is much more lagging so less heat escapes to keep the tank liquid. Not only does our tank have a lid but it's also lagged and it will stay that way.