Problems with hot water tank and overflow pipe

karlie88

Afternoon everyone.

Think I've got a developing problem with my hot water tank and its overflow pipe.

Water leaks from the overflow pipe when we haven't used any hot water in the household; timescale for this to happen is approx. 24 hours. Initially, when this occurs, the water leaks at a rate of a few drops per minute. This steadily increases over the course of a day to a drop every second.

Any ideas what the problem could be? Is the water level in the tank rising?

Here's a picture of our hot water tank for you to get an idea of what the problem may be.



Any advice would be appreciated.

Thank you.

southcoastrgi

you have a overflow from something else (do you know what it is ?) connected in to the one that goes out the wall are you sure it's not this overflowing ? if not then i would say your ballvalve either needs adjusting or replacing, as the water heats in the cylinder it will expand into the top tank therefore if the ballvalve is set too high when the water level goes up in the tank it will go out the overflow, just as a matter of interest do you know what that large thing on the pipe on the right hand side is ?

Kernel_Sanders

Is your cylinder under mains pressure or is it fed from a header tank? If not the former, is the top third of that cylinder the cold water storage vessel?

southcoastrgi

Kernel_Sanders wrote: »

Is your cylinder under mains pressure or is it fed from a header tank? If not the former, is the top third of that cylinder the cold water storage vessel?

no it's not mains pressure no other header tank (apart from the F&E tank for the heating side) yes the CWS is the top third of the cylinder.

however i would be slightly concerned at the valves on the flow & return to the coil on the right hand side especially as one on the flow looks like a non return valve.

karlie88

southcoastrgi wrote: »

you have a overflow from something else (do you know what it is ?) connected in to the one that goes out the wall are you sure it's not this overflowing ? if not then i would say your ballvalve either needs adjusting or replacing, as the water heats in the cylinder it will expand into the top tank therefore if the ballvalve is set too high when the water level goes up in the tank it will go out the overflow, just as a matter of interest do you know what that large thing on the pipe on the right hand side is ?

Thanks for the response.

The other pipe to the overflow is the header tank (I believe). When we got it installed a few years ago we were told that this needed to be above the hot water tank. As a result, we put the header tank in the attic and had some pipes feeding through; as you can see.

What does the header tank do? If that's the problem, what could it be?

I'm afraid I have know idea what that large pipe is on the side.

karlie88

Kernel_Sanders wrote: »

Is your cylinder under mains pressure or is it fed from a header tank? If not the former, is the top third of that cylinder the cold water storage vessel?

You've lost me.

We have a header tank in the attic which is connected to the main hot water tank. So I assume it's fed from a header tank? Although I've always thought that the cold water goes straight into the big tank and it gets heated in there.

What does the header tank do?

southcoastrgi

then you need to go into the roof & make sure the water isn't too high in there, overflows should always be run seperately so you can tell which is dripping

keystone

karlie88 wrote: »

The other pipe to the overflow is the header tank (I believe).

Looks likely

What does the header tank do? If that's the problem, what could it be?

Feed and expansion for the central heating.

I'm afraid I have know idea what that large pipe is on the side.

Mmmm. Where does it come from and where does it go. Its clearl;y a length of 28mm pipe in a 15mm run. If its the cold feed for the CH and the path from the F&E tank is convoluted it might just be just to optimise flow.

Break the overflow pipe at the T connector - put a bucket under it first.. Then you can easily see which one is overflowing.

Cheers

keystone

karlie88 wrote: »

You've lost me.

Don't worry - blind leading the blind then.

We have a header tank in the attic which is connected to the main hot water tank

Are you sure? Have you traced the pipes. Its more likely that its the feed and expansion tank for the central heating.

So I assume it's fed from a header tank? Although I've always thought that the cold water goes straight into the big tank and it gets heated in there.

You have a combination cylinder. The top third is your cold water storage tank and the hot water cylinder is fed from that and NOT from something in the roof. The cold from the mains riser goes into that top section of the cylinder and then into the bottom section.

What does the header tank do?

feed and expansion for the central heating.

Cheers

southcoastrgi

keystone wrote: »

Its clearl;y a length of 28mm pipe in a 15mm run

the thing i was saying about is on the 22mm copper pipe it looks to me to be about 40mm

keystone

yes you are correct. Age deceived my eyes glancing at the picture. Same idea though?

Cheers