Soldering onto an existing fitting

[dan1w]

I need to move a radiator, it's 10mm microbore and the pipes are buried in a brick wall.

The pipework runs vertically downwards and coming out of the wall there is an elbow, then about a millimetre of pipe is visible before the next elbow that runs up to the TRV/valve.

I would like to remove the elbow before the TRV by heating it and then solder a new elbow on the small piece of pipe that is already there. Obviously these elbows are in very close proximity and I'm worried I'm going to ruin the joint on the elbow that is buried in the wall.

What would the pros do here?

Any tips much appreciated,

Dan

 

[Agile]

Without a picture it is a little difficult to imagine what you have and what problems may arise.

10 mm tube is pretty small and I would solder close to an existing fitting using some kind of heat sink to keep the retained fitting cooler.

Tony

 

[dan1w]

 

[dan1w]

There's a bit more space between the fittings on the side shown, the other side is just a sliver of pipe between them.

So I want to remove the elbow below the TRV and replace with the same, just running horizontally instead of vertically.

 

[Doggit]

Carefully clamp a pair of mole grips round the pipe as it comes out of the wall.

 

[Agile]

But before any soldering you will probably need to blow the water out of the pipe!

Tony

 

[Doggit]

Well spotted Tony; forgot that part of it. If you're replacing the elbow, cut it off with an angle grinder at the bend, or use a junior hacksaw. There'll be a lot of water in the pipe in the wall, and you may have to drain the upper part of the system as well.

 

[dan1w]

Cheers for the replies guys.

I was hoping to just remove the elbow and leave the pipe attached to the other elbow.

If I cut the pipe, how will I get the new elbow on?

 

[dan1w]

Or do you mean cut into the elbow itself and then remove the remnant after the water had drained?

 

[GeeTee]

If I'm seeing it right... there's an elbow in the wall, a short length of pipe then another elbow to go from horizontal to vertical up to the current TRV.

Given the state of the plaster around the elbow in the wall, I'd be inclined to hack the plaster out around it - it needs making good anyway and will give you some wiggle / bend room to work on the embedded elbow.

As above - you need to get the water out of the pipework to have any chance of (de)soldering anything successfully - else you will just make a lot of steam and gurgle noises.

You don't mention your system type or whether this is ground or upper floor - but I may be inclined to hack away the plaster up the pipe run in the wall a distance then apply a pipe freeze on the feed to the pipe to the TRV and shut the lockshield valve on the other end of the radiator. That way you are only having to drain the one radiator rather than the entire system. I'd suggest hiring an electric pipe freeze rather than try and rely on the aerosol type ones.

Once frozen and lockshield closed, cut the elbow nearest the TRV to drain the rad and pipework (red line in the below) - this will result in a surprisingly large amount of water - be prepared with enough containers! Clean the crap off the elbow in the wall and as per Doggit above apply some chunky locking mole grips gently (green splodge in the below). Then direct your blow torch on the remains of the elbow you want to remove.

The idea being is that the additional metal the mole grips bring helps wick the heat away from the joint you don't want to de-solder.

Good Luck!

 

[Aquaheat]

Well spotted Tony; forgot that part of it. If you're replacing the elbow, cut it off with an angle grinder at the bend, or use a junior hacksaw. There'll be a lot of water in the pipe in the wall, and you may have to drain the upper part of the system as well.

Are you for real? What is your plumbing or heating system background?

OP drain system.
Assuming no drain off on that leg then wet vacs are your friend.
Suck water out
Heat sink gel on joints you don't want unsoldered or a very careful flame.
Clean up properly and re solder. (heat sink again if needed.)
2 hours if it goes OK.

Jon

 

[Aquaheat]

If I'm seeing it right... there's an elbow in the wall, a short length of pipe then another elbow to go from horizontal to vertical up to the current TRV.

Given the state of the plaster around the elbow in the wall, I'd be inclined to hack the plaster out around it - it needs making good anyway and will give you some wiggle / bend room to work on the embedded elbow.

As above - you need to get the water out of the pipework to have any chance of (de)soldering anything successfully - else you will just make a lot of steam and gurgle noises.

You don't mention your system type or whether this is ground or upper floor - but I may be inclined to hack away the plaster up the pipe run in the wall a distance then apply a pipe freeze on the feed to the pipe to the TRV and shut the lockshield valve on the other end of the radiator. That way you are only having to drain the one radiator rather than the entire system. I'd suggest hiring an electric pipe freeze rather than try and rely on the aerosol type ones.

Once frozen and lockshield closed, cut the elbow nearest the TRV to drain the rad and pipework (red line in the below) - this will result in a surprisingly large amount of water - be prepared with enough containers! Clean the crap off the elbow in the wall and as per Doggit above apply some chunky locking mole grips gently (green splodge in the below). Then direct your blow torch on the remains of the elbow you want to remove.

The idea being is that the additional metal the mole grips bring helps wick the heat away from the joint you don't want to de-solder.

Good Luck!

Oh dear God!

 

[GeeTee]

Oh dear God!

Care to expand on that?

 

[Aquaheat]

Not really as I've already explained the way forward in a previous post. To start ripping walls apart and applying freezing kits is shocking advice.

As a last case scenario then possibly but it can be drained, it can be accessed and it can be done a hell of a lot easier.

Oh bugger I did elaborate!

Jon

 

[GeeTee]

Ripping walls apart - not so much... the wall already needs making good going by the OP's photo - so a little extra digging up the wall is not a problem.

Why not just drain the one rad rather than the entire system? Unless there is something to be gained by having to re-treat the whole system with inhibitor because it had to be drained and refilled.

You've explained your own way forward as a professional - yet this is a DIY forum.