Dripping from overflow pipe out of loft

PeteW

Hi,

We've got a cold water tank in the loft and two overflow pipes which go out of the eaves. One of them has been steadily piddling away on and off for a while now.

I can tell that one of the pipes goes to the overflow at the top of the tank, but I couldn't tell which one - The other pipe isn't visible in the loft. I have a vague recollection of it going under the loft boards when I boarded the loft years ago.

In the hope that it was the visible pipe that was dripping, I replaced the ball valve. I've just seen the pipe is currently flowing so had a look at the water level is below the overflow outlet at the top.

So it must be the other mystery pipe. Before I go clearing out the loft and taking up the loft boards, can anyone give me any clues as to where this second pipe comes out and why it would be overflowing?

Cheers

Pete

EssexExile

Do you have another tank up there, a feed & expansion tank for example?

PeteW

EssexExile wrote: »

Do you have another tank up there, a feed & expansion tank for example?

It appears I do! Having had a a rummage, there was a small tank hidden between the big tank and wall and covered by a load of insulation - which seemed to have caused the problem. Some of the insulation has touching the water and so had soaked it up and then weighed down the ball valve.

Which brings me to my next question… is it normal for the water in this smaller tank to be all orangey-brown? Is that because it's from the heating circuit and discoloured from rusty pipes/radiators, or has it been contaminated by the orange insulation that was in it…?

EssexExile

PeteW wrote: »

It appears I go! Having had a a rummage, there was a small tank hidden between the big tank and wall and covered by a load of insulation - which seemed to have caused the problem. Some of the insulation has touching the water and so had soaked it up and then weighed down the ball valve.

Which brings me to my next question… is it normal for the water in this smaller tank to be all orangey-brown? Is that because it's from the heating circuit and discoloured from rusty pipes/radiators, or has it been contaminated by the orange insulation that was in it…?

Yes it's normal for it to look rusty & disgusting! Especially if it hasn't been flushed through lately.

PeteW

So, after removing the insulation weighing down the ballcock in the smaller tank, it still overflowed.
I replaced the ballcock and it still overflows.

From a bit of Googling, it suggests that there may be a hole in the coil in my water cylinder that may be the root cause. We've had a couple instances recently of the water from our hot taps looking a bit murky which I think supports this.

Can anyone confirm if this likely the issue, or if there's anything else to rule out or a way to confirm this? And is there any other fix other than replacing the water cylinder? We'll be having a full overhaul of the heating system next year when we build our extension (new boiler, cylinder etc) so any temporary fix until then would be useful…

nofoollikeold

1. There are no temporary fixes for a leaking cylinder coil.
2. You need to see where the excess water is coming from:
2a. If from the pipe bent in a U shape over the top of the Feed and Expansion (F&E) tank, then it suggests an issue with the boiler primary circuit. Possible candidates include blocked feed pipe to system, pump on too high a setting.
2b. If from the pipe which feeds the system (bottom outlet pipe) then pin holed hot water cylinder coil is likely.
2c. Having replaced the ballcock, have you reset the inlet valve so that the inlet shuts off when the water level is at around 4 inches above the bottom of the tank? The tank shouldn't be full when the system is cold. It's job is to cope with the Expansion of the water in the system when it is heated, and Feed that water back into the system as it cools. If the initial volume is too high, the expansion water will cause the overflow.

PeteW

nofoollikeold wrote: »

2c. Having replaced the ballcock, have you reset the inlet valve so that the inlet shuts off when the water level is at around 4 inches above the bottom of the tank?

I haven't no, nor can I find any guides on the internet on how to do that. Could you give me any clues please? Last chance before I have to give up and call a plumber

grumbler

The ball can be moved up and down along the metal rod it sits on, can't it?
Release the bolt a little, move the ball down to the position at which the flow stops completely at the level you want. Sort of trial&error job. Then tighten the bolt back.

PeteW

grumbler wrote: »

The ball can be moved up and down along the metal rod it sits on, can't it?
Release the bolt a little, move the ball down to the position at which the flow stops completely at the level you want. Sort of trial&error job. Then tighten the bolt back.

Ah yes, I've adjusted that, but the water level is well above the ball. I don't think it's coming from that valve.

grumbler

Just remove unneeded extra water.

If the level drops below the chosen one, the ball valve will top up the tank.

Sometimes the level can be higher a little because of water thermal expansion, but not lower.

-taff

I had the same thing [overflowing expansion tank] but mine was solved with as above, removing the excess water and then a new ball valve adjusted to sit below the outlet pipe. Took a few goes of fiddling with it to get it right, but that worked for me.
Unfortunately, I can't help if it's not the ball valve.