Leaking Pipe - need to drain water.(GCH pipe) need some advice.

[Joe Bloggs]

It's seems I have a leaking pipe somewhere, I noticed some water seems to be in the plaster of a downstairs wall, some bubble in paint and small seepage from a couple of small picture frame pin holes, also slight discolouration of part of the ceiling above the affected area. It's only a minor leak (at the moment) but it has became more apparent when I have had the heating on. It may have been leaking for a few weeks as I had noticed a slight damp smell but I assumed it was condensation or similar. Anyway I am pretty satisfied it is a leak in a pipe to the radiator in the room above (bathroom) because firstly I turned the main water supply off and that didn't seem to stem the flow. Then I turned off the hot water to the taps via a valve near the hot water tank, that didn't stop it either. Then I decided to drain the radiators (I had assumed they were on the same circuit as the hot taps but I think that was not the case at all). Anyway I drained a downstairs radiator 'drainage valve(?)' and that seemed to stop the water seeping out of the wall so I was quite pleased about that, but then I began thinking about this meant regarding the boiler (I only had a pretty basic grasp of what I was doing!!) I think I was effectively draining the pipe which the boiler heats inorder to heat the radiators and also the water in the hot water tank so I became concerned that this would not be a good idea if the boiler was on so I did a quick check on the control unit and noticed it had just clicked to on for hot water (but not for the radiators) so I quickly switched it off. (It seemed a remakeable coincidence that this had happened just as I was draining it but never mind it didn't seem to do any harm but I wish I had checked it first, I has assumed it was set to off). Would that be a problem if the boiler had fired up with out any water in the pipe I assume I had probably drained?). I don't think I entirely drained it, just enough to stop the very small leak (trickle) from the wall pin holes? Anyway I then turned the boiler off completly after about an hour (pilot light was still on but I turned that off by turning the gas control knob on the boiler (glowworm). It's probably what you would call a 'bog standard' glow worm system that was installed about 30 years ago. So now I need to lift some floorboards to try and fiind the leak and fix it (never lifted boards before but I expect I will manage it somehow) I have never fied a leak before either, I was thinkning I could wrap something around it which may be fairly easy as it low pressure hot water I assume. I just wanted a quick fix which I may be able to do tomorrow when I find the cause of the leak, then maybe do something more permanent later (or get someone to do it for me). It might take me a few days to get to the leak and sort it out, so I would like to be able to maybe put the central heating on for a while as the next few days might be a little chilly and I don't think the small seepage would be too much of a problem for an hour or two, then I could redrain it again to stop it seeping once I had heated the place up a touch. The thing I am unsure about is how to fix the leak, should I wrap something around it it would not take mush as its pretty low pressure (a few feet (8?) of water. Any comments? does that sound reasonable? It might take me a few days to do a good job if I need to buy anything to do a good job? Comments? Would having the boiler on (briefly with possibly no water in the pipe it heats be a concern?). I assume it won't be a problem (fingers crossed!!)

TIA.

[Joe Bloggs]

The pipes (to the rads) are very small ones, about 7mm? Also the boiler had not been used for a long time (4 months) due to a fault (didn't need it in summer anyway).

[Sparks]

No, the water in the radiators just gets pumped round and round, it is not connected to the water that comes out of the taps.

This same water gets pumped round a coil of pipe in your hot water cylinder, the water that comes out of the hot tap is heated by this coil of pipe.

There are two main types of heating systems, sealed and vendted.

In a vented system, there is a small water tank, usually in the loft (This will be higher than the highest radiator and higher than the hot water cylinder) - this keeps central heating system topped up automatically.

If you have one of these, you need to stop it from filling, otherwise, no matter how much water you drain off, it will just keep filling :-)

In a sealed system, there is a flexable pipe, usually near the boiler, the "Filling Loop" one end of this will be connected to the mains water supply, and the other end to the heating pipes. This allows you to add more water to your heating system. (When you have finished filling the system with water, this loop *should* be disconnected, but usually isn't! There should be a pressure guage on or near the boiler, this show how much pressure the system has.

Do you have a pressure gauge and a filling loop, or do you have a small header tank?

It can cuase daname if the boiler is dry, however there should be a safety lock out, that trips if the boiler gets to hot - if it was only on for a very short time, I am sure it will be fine. (When you drained the system, I expect you didn't actually drain the water in the boiler anyway)

Then I would think it is almost cerntainly a vented system.

Let's find the leak first...

It might take me a few days to get

You really need to find the leak before you refill, or it could get a lot worse!

Find the leak forst...

It depends on the source of the leak, find it!

I doubt it - but don't do it again :-)

If in doublt, ask before you start next time!

I expect they are 10mm

Sparks...

[Qatar Airlines Passanger]

There is definately a tank in the loft so its vented, I stopped it filling buy turning the cold water off at the stopcock, but this means no cold wather either but I can turn it on breifly and get some without any leakage apparent in the wall, maybe I woulus be better off doing it in the loft but its small and crammped up there.

No pressue gauge, I have tank in loft so its vented.

But I think its the same pipe which goes through the radiators? The hot watertaps are drained too but thats less of a prob. I guess the worst thast I could do is that I melted that pipe but that must be unlikely as pots and pans dont melt on the stove do they?!

Thanks I need to lift some floorboards now, I am not sure if I have a too suitable for raising then up but I maybe I can find something other wise I will have to go to homebase of B&Q.

Thanks for your help.I will let you know how I get on.

[Sparks]

Yes, if you just tie the ball c*ck up, so it can't drop and fill the tank, this will be fine (assuming there isnt a stopcock just before the ball ock) - You may need to bang a nail into a joist above to secure the string/rope, or simply lay a piece of wood over the top of the tank and tie it to this.

The pipe will simply connect to the heat exchanger (usually cast iron) so you should be fine.

The last time I had to lift some boards, I used a large flathead screwdriver and a hammer :-)

The problem arises when you have a board that goes under somthing - then you need to cut the board in the middle of a joist. (The nails holding the board down should mark the middle of the joist)

I expect that bards were lifted to install the heating, so hopfully you can spot these and lift them.

I usually screw the boards back afterwards instead of nailing them - makes removal later easier and makes it less likley you will damage the boards when trying to get them back up.

Sparks...

[Qatar Airlines Passanger]

"Sparks" wrote in message news:4548f2ce$0$628$ [e-mail]...

I think there are two tanks in the loft IIRC, the nearest on seemed to be covered with some sort of insulation, the furthest one is really hard to get to if it is indeed a tank, the loft ceiling is very low near the tanks, it seemed easier to turn it off at the main stop c*ck.Especially as I wanted to do it quickly.

Yes I guess so.

Well I did have a look at them and try to lever one up but with no luck. I had even bought a wide chisel tool called an "electicians flooring tool" but it looked too thick to fit between any gaps, I asked one of the assistants if it was suitable but he didn't give a clear answer and went to luck for the 'assistant who knows about plumbing" (former plulmber by the sounds of it) but seemed to have finished his shift. I also bought some stuff like putty which supposedly could be used to fix leaks, at least temporilly. The board I wanted to lift was under the skirting board on one side and at one end, it even went under a door frame. It was not a normal board any way, seemed to some sort of green chip board, the board next to it was of the same stuff but about 2 foot wide. Anyway it didnt look like I could lift them. So I was trying to 'dig around' a nail to see if could get a claw hammer on it to extract it. (Seemed like the best option at that point). Anyway as I was doing this I got a knock on the door from my neighbour, I though they were going to complain about the noise but it transspired that they had been having problems too. I had suspected the water was coming through from their side however as the leakage stopped when I was draining the radiator I assumed the problem must be on my side. Looks like they drained theirs or turned something off at about the same coincidently (well not too much of a coincidence under the circumstances). Turned out they had had a shower installed last week (I wondered what the noise was, the walls let noise through as easilly as water!). They said they had the plumber back and he fixed it but that it had started leaking again, however none has came through to my side so I was a bit confused, they also said he was coming around tomorrow morning to fit it. Anyway I have had my central heating (and water) on for almost 2 hours and not a trace of any leakage which is a great relief!! I don't think I would have had much luck with those boards. Thinking about it the best way would probably have been to drill the heads off the screws then drive some screws in to try and pull it up. The boards are not proper wood some sort of chipboard with not much strength in it it would be hard to lever them up unless you got right beneath them. Anyway I am relieved I have my heating back and no major job to do. I have just discovered that if I prick the bubbles in the paint I can press them out (they seem to be air not water as I first thought) and they will dissappear without a trace. I guess I would be within my rights to charge my neighbour for the £10 I spent at B & Q on a wedge chisel and a leak repair 'kit' but I guess they may come in useful sometime and I think I can return them anyway, they said I could return the chisel if unused so same probably applies to the kit. I am just relieved I have my central heating back especially looking at the forecast for then next few days!!