Leaking overflow from the attic - help please

[LukeR]

I have a leak from my cold water tank in the attic when water has not been used recently, and no hot water.

The ball valve seems fine.

I have another smaller hot water tank that is higher up than the main tank.

I'm guessing that the hot water tank is leaking back into the main tank, thus causing overflow and the lack of hot water? I do not know how to fix this - please help!

Thanks

 

[Dan Robinson]

You need a new hot water cylinder.

 

[LukeR]

Thanks Dan,

Is it not likely that the current cylinder can be fixed? A new one is expensive...

Thanks

 

[Dan Robinson]

No, there is a hole in the coil. Only other option is a sidewinder thingy that replaces the immersion heater. But it is not practical.

 

[gaswizzard]

As Dan says or maybe a passing mixer valve? , is cold water to outlets fed via mains or cold water storage cistern?

Issolate ballvalve to higher cistern and note if water level lowers.

 

[LukeR]

Thanks gaswizzard,

There is a cold water storage cistern in the attic. Could it be possible that there are some cold water outlets that use mains AND others that use the cold water cistern? If so then might there be a dodgy mixer valve/tap feeding cold water back up the hot water pipes, thus causing a lack of hot water and overflowing the cold water tank in the attic?

Thank you