Not found this in the FAQ and various searches have only come up with
incomplete information so here goes....

There is a leak a few centimetres below a radiator valve and my plan to
repair is this (we have a sealed system btw and the pipe concerned is
narrow-bore):

1. Screw the radiator valve fully shut
2. Cut the pipe below the level of the floorboards and quickly jam on a
suitable pushfit/speedfit stop-cock (or similar) that's closed.
3. Then at leisure replace the dodgy section of pipe with new pipe.

Is 2 likely to be problematic and should I get some freezing spray also? Or
am I just likely to lose a little bit of water?

Or is the whole process flawed?

Thanks

Rob

Rob Summers wrote:
Not found this in the FAQ and various searches have only come up with
incomplete information so here goes....

There is a leak a few centimetres below a radiator valve and my plan to
repair is this (we have a sealed system btw and the pipe concerned is
narrow-bore):

1. Screw the radiator valve fully shut
2. Cut the pipe below the level of the floorboards and quickly jam on a
suitable pushfit/speedfit stop-cock (or similar) that's closed.
3. Then at leisure replace the dodgy section of pipe with new pipe.

Is 2 likely to be problematic and should I get some freezing spray also? Or
am I just likely to lose a little bit of water?

Or is the whole process flawed?

Thanks

Rob

I would de-pressurise the system first - only takes a couple of minutes
and may save you from getting very wet! If you do this you can do the
whole job in 15 mins or so, including replacing the leaking pipe.

BTW, are you sure it IS the pipe that's leaking, rather than water
running down the pipe from a leaking valve or olive?

Dave

Dave wrote:
I would de-pressurise the system first - only takes a couple of minutes
and may save you from getting very wet! If you do this you can do the
whole job in 15 mins or so, including replacing the leaking pipe.

Sounds good. I now need to find out where to depressurise the system I guess
it's the pressure vessel in the boiler (it's a glow-worm sxi) that needs
fiddling with. (Will check the sealed-system FAQ)

BTW, are you sure it IS the pipe that's leaking, rather than water
running down the pipe from a leaking valve or olive?

Yup, the pipe is kinked and I dislodged some limescale while trying to patch it up
awaiting a proper repair and the limescale had done a reasonable job of
healing the problem..... it's much worse now!

Thanks

Rob

Rob Summers wrote:
Dave wrote:

I would de-pressurise the system first - only takes a couple of minutes
and may save you from getting very wet! If you do this you can do the
whole job in 15 mins or so, including replacing the leaking pipe.


Sounds good. I now need to find out where to depressurise the system I guess
it's the pressure vessel in the boiler (it's a glow-worm sxi) that needs
fiddling with. (Will check the sealed-system FAQ)

.... snipped

There may be a dedicated drain point, you may be be able to
de-pressurise via the filling loop connection or there may be a drain
point on a rad valve somewhere.
The amount of water to drain will depend('ish) on the size of the
expansion vessel; our 30SXi has an 8 litre internal expansion vessel.

Dave

On Wed, 03 May 2006 16:06:46 +0000, Rob Summers wrote:

Dave wrote:
I would de-pressurise the system first - only takes a couple of minutes
and may save you from getting very wet! If you do this you can do the
whole job in 15 mins or so, including replacing the leaking pipe.

Sounds good. I now need to find out where to depressurise the system I guess
it's the pressure vessel in the boiler (it's a glow-worm sxi) that needs
fiddling with. (Will check the sealed-system FAQ)

BTW, are you sure it IS the pipe that's leaking, rather than water
running down the pipe from a leaking valve or olive?

Yup, the pipe is kinked and I dislodged some limescale while trying to patch it up
awaiting a proper repair and the limescale had done a reasonable job of
healing the problem..... it's much worse now!

Thanks

You may find that turning the boiler flow/return isolators is easier and
simpler than depressurising.
You then need only to remove a small amount of water to depressure the
rest of the system (unless there is a lot of air somewhere). Watch out if
there are any other auto-vents outside of the boiler to catch you out.

Make sure you have the right size of speedfit fitting.
Clean the pipe before cutting it.
Put a towel under anyway you won't stop every last drop.

--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
Choosing a Boiler FAQ http://www.makewrite.demon.co.uk/BoilerChoice.html

Rob Summers wrote:
Not found this in the FAQ and various searches have only come up with
incomplete information so here goes....

There is a leak a few centimetres below a radiator valve and my plan to
repair is this (we have a sealed system btw and the pipe concerned is
narrow-bore):

1. Screw the radiator valve fully shut
2. Cut the pipe below the level of the floorboards and quickly jam on a
suitable pushfit/speedfit stop-cock (or similar) that's closed.

a) It will spray water out while you're cutting it
b) Can you get pushfit microbore?
c) Pushfit needs (in theory) the pipe to be deburred before putting the
fitting on
d) You might need to put the stop-cock on open, given the system is
sealed. In any event, an open stop-cock will help direct the water flow.

I'd use a compression fitting, and I'd drain enough water out to
depressurise the system first (i.e. don't fully drain out, just drain
until the pressure gauge hits zero).

Ben

3. Then at leisure replace the dodgy section of pipe with new pipe.

Is 2 likely to be problematic and should I get some freezing spray also? Or
am I just likely to lose a little bit of water?

Or is the whole process flawed?

Thanks

Rob

Rob Summers wrote:
Not found this in the FAQ and various searches have only come up with
incomplete information so here goes....

There is a leak a few centimetres below a radiator valve and my plan to
repair is this (we have a sealed system btw and the pipe concerned is
narrow-bore):

1. Screw the radiator valve fully shut
2. Cut the pipe below the level of the floorboards and quickly jam on a
suitable pushfit/speedfit stop-cock (or similar) that's closed.
3. Then at leisure replace the dodgy section of pipe with new pipe.

I've in the past done:
1...

2. Clamp the pipe absolutely flat, over a distance of 3cm or so.
3. Disconnect from radiator, and fold pipe over, before clamping again.
4. Cut end of pipe.
5. Apply flux, and heat below join, so the pipe fills with steam.
6. Apply solder to the flattened end of the pipe.

It actually worked, but is a bodge.
With several more folding over steps, and enough force applied, that
alone should work.

Thanks for all your input. I think I know what to do....

..... and on Saturday will find out if I can.

Rob