What is this water tank?

Question

is it the radiator feed?

its in the loft, its only smallish, has a ballvalve with a cold feed, another pipe coming of it at the side, and a pipe that seems to pour hot water into it which comes from the other tanks.

why is hot water going into it from this other tank? is that some overflow?

im asking because ive replaced the ball valve because water was pouring out the overflow outside, but im now wondering if there is a problem with the other tank (why is hot water going into this small tank)

sorry this may sound very confusing- but if someone could explain that would be great.

Answer 1

Sounds like an expansion tank or pressure tank..... Does it have an air valve(like on a tire)?

http://en.wikipedia.org/wiki/Expansion_t...

Answer 2

It is probably your header tank to ensure that the system stays full of water.

Answer 3

It sounds like a header tank.(sometimes called a Feed & Expansion tank).Is water coming out the open vent? Thats the pipe that loops over the top.If so it could be a blocked cold feed pipe which is causing the system to 'pump over', thus filling the tank with hot water & then out the overflow.Best way to tell is to see if it does it only when the system is running.If so then I would say this or the coil in the hw cylinder has gone.Turn the system off at the programmer/clock so it doesnt come on in the morning & see if it stops.Suggest doing it over night to see. Are you sure there is a pipe connecting the 2 tanks?(assume you mean the 40 gallon big cold tank & not another F&E tank)? If its a plastic pipe its probably is the overflow but officially they should have their own seperate overflows.More info would help me to help you!

Answer 4

YOU HAVE OIL OR GAS CENTRAL HEATING AND UNFORTUNATELY IT SOUNDS AS THOUGH THE COPPER COIL INSIDE YOUR CYLINDER[COPPER TANK] HAS CORRODED AND THEREFORE THE WATER PRESSURE INSIDE THE TANK ITSELF IS FORCING WATER FROM THE TANK INTO YOUR HEATING SYSTEM..

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