"Sparks" wrote in message
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"Joe Bloggs" wrote in message
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"Joe Bloggs" wrote in message
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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).

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 usually 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.

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,

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 :-)

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.

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?

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

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?).

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)

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?!




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.

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

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).

Let's find the leak first...

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.

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

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

Find the leak forst...

if I need to buy anything to do a good job?
Comments?

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

Would having the boiler on (briefly with possibly no water in the pipe
it heats be a concern?).

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

If in doublt, ask before you start next time!

I assume it won't be a problem (fingers crossed!!)

TIA.


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).

I expect they are 10mm

Sparks...

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.