Pipe freezing kits.

ronnyb

Anybody used one of those DIY pipe freezing kits? One of the TRV's is stuck on a radiator and i need to change it. I've done all the things to try and free it off but to no avail. Just wondering how successful the kits are to avoid draining down the system.   

boogieman

Seen a plumber use one on a cold water pipe and it worked fine, not seen it used on c/h though.

Is it a conventional heating system? Wouldn’t fancy using it on a pressurised one. 

ronnyb

Yes, pressurised combi system.

Jono111

You don't need to drain down the system, shut off the other end of the radiator, shut the radiator off before the one you are dealing with and put jugs and towels down under the trv. There is not too much water lost when taking the trv off as a vacuume is formed in the radiator and pipe. Obviously done with the heating off. As long as you crack the nut slowly you can regulate the outward flow.

boogieman

Should be ok then, only running around 1 bar. 

When you say the TRV is faulty, is it definitely the valve part and not just the head? You can change that without breaking into the wet side. Also, have you tried taking the head off and tapping the pin with a hammer? They do get jammed in place, especially if the rads have been off all summer. 

ronnyb

Yes, i've tapped the pin with a hammer and hit the side of the valve to try and unjam it. i daren't hit the pin too hard because i'm told they can fly out.  

Headphones

Have used the DIY ones with success for just the job you describe.  Easy to do too.

That said, when I've replaced recent ones I've simply isolated one end using the lockshield.  Cracking the TRV/pipe then opens the system and a bucket or so of water is loosed as the pressure is let off (if you have a VAX it's really easy).  The water stays in the rad as it needs air in to get out, of which there's little route, same for the other side.  The suggestion of closing other rads above is not really helpful as (with most systems) the rads are all in parallel.

ronnyb

Might give a freezing kit a go, only £15 at Wickes.

TheMadMick

Make sure you have an olive cracker to get the old olive off the pipe and PTFE tape to ensure the valve to radiator joins are sealed (shouldn't need this last but best to be sure). Suppose I don't need to say - ensure you have the new valve etc. I have a spare Peggler Yorkshire one if you want it.

Jono111

It is also helpful if you can tell before you start if your radiator has metric or imperial threads, don't ask.

ronnyb

TheMadMick said:

Make sure you have an olive cracker to get the old olive off the pipe and PTFE tape to ensure the valve to radiator joins are sealed (shouldn't need this last but best to be sure). Suppose I don't need to say - ensure you have the new valve etc. I have a spare Peggler Yorkshire one if you want it.

Thanks for the offer of the valve but i've got one that was left over when the system was installed. 

hywelg

Jono111 said:

It is also helpful if you can tell before you start if your radiator has metric or imperial threads, don't ask.

Seriously? Since when has anything other than ½" BSPT been acceptable? Has someone been importing EU rads on the cheap? Thank god for Brexit....  

Simonh

I’ve used one replacing the main stop cock at my last house, that was a nerve wracking experience but it worked as advertised!

chillidoggy

WTF's an 'olive cracker'? Sounds like a bar snack.

ronnyb

That's an Olive cracker.

boogieman

chillidoggy said:

WTF's an 'olive cracker'? Sounds like a bar snack.

I’d never heard of them either, but apparently they’re an actual thing… looks like a pair of pliers and grips the olive while a blade cuts through. I’ve always just cut them off with a junior hacksaw. 

https://www.toolstation.com/hand-tools/plumbing-tools/c672?type=Olive+Tools

Headphones

Have done this job a lot and never had the need for an "olive cracker", nor found weird threads, simply swap at the existing unions.  Done twenty-five this year so far.

No, I'm not a plumber.

The most challenge I've encountered is where microbore pipes are used, as there can be a limited variety of valve that will swap in, due to the length of copper tail available and where the olive sits in the valve body.

Kittyfrisk

Hacksaw method was fine for me too... until I had to replace an electric shower unit where the existing pipe stub was very short & close to the tiled wall. Stuck olive & no space to get in with a saw but an olive cracker did the job beautifully. 
Right tools for the job & all that.

chillidoggy

boogieman said:

chillidoggy said:

WTF's an 'olive cracker'? Sounds like a bar snack.

I’d never heard of them either, but apparently they’re an actual thing… looks like a pair of pliers and grips the olive while a blade cuts through. I’ve always just cut them off with a junior hacksaw. 

https://www.toolstation.com/hand-tools/plumbing-tools/c672?type=Olive+Tools

All those years of me using a junior hacksaw, and that little beauty was available?