I need to change the plumbing to a radiator in the bathroom I'm installing.

Rather than draining down the system (it's a nightmare to get it all back and balanced!) I was wondering about those cans of freeze spray I've seen at £9.99 from Screwfix.

And good?

Do you need a whole can per piece of 15mm pipe? As there's a couple of pipes to do and could get expensive... but then Fernox isn't that cheap either!

How close to the frozen area can you blowtorch and solder?

Thanks!
James

does Fernox contain antifreeze?

Just checked Fernox web site, Alphi-11 has an antifreeze, not all for Fernox's inhibitors do.

[Edited on 19/11/10 by Bluemoon]

They work a treat. I cut the supply to the old extension using freezer cans, then fitted isolation valves, saved me hours of draining down. You might get away with 2 freezes per can, but I wouldn't risk it - there is a lot of water in a typical system.
However, I recommended the technique to a mate who wasn't so lucky. Don't know exactly what he did wrong, but he wasn't as delighted as I was!

Theyr good. You need 1 can per freeze if you want more than a couple of minutes to work. Freeze it the furthest away as possible if you want to solder. The heat is sucked up the pipe.

Surely be easier just to put a compression joint on (ideally with isolating valve in it)?

As per comments above
- freeze well away from where you want to solder
- 1 can per freeze (i.e. 2 per radiator)
- leave the wrap on the pipe
- have a spare can around "just in case"

Used them several times for radiators, showers, sinks and baths...never had an issue...

i usually snatch it to avoid wasting all the inhibitor. Let water out til the pressure is near zero, close the valves at the radiator, then just cut the pipes and wap a compression iso on as fast as you can. The rads and pipes are all still full of water, but without the 1.5bar pressure it doesnt come out that fast.

Of course, if you get stuck, you are well up s*** creek.

I've hired a freeze kit in the past. Nothing like the aerosol type things (which I have also used to the cost of my nerves!) but a pair of clamps and a machine that freezes the hell out of the water! I used it for 2" steel pipe and 15mm copper. The 15mm copper pipe had hot water in when I started but within 2 minutes was as frozen as a frozen thing. Perhaps enquire how much for a mornings rent? Could be cheaper than two aerosols?

Hmmm. Bit pricey but I'm sure we hired one for less. Could try ringing around?
http://www.hss.com/g/68816/Pipe-Freezer-12-42mm-240v.html

Thanks everyone for the advice.

Plan was to fit a couple of valves so I can change the rad at a later date and generally mess about.

Almost tempted by Joel's plan of just cutting the pipe and banging them on but my Dad's office is the room beneath and it's full of his business stuff and it's just not worth the risk as there's barely any ceiling with that room not being decorated yet!

Things have got a little more complicated since posting as I need to move some other stuff as well now.


Probably going to be sensible and drain it (having closed all rad valves etc.).

But good to know people have had success with the freeze cans as that could be useful for the future!

Cheers,
James

James

If im reading your post correctly, the offending Rad is upstairs, so you dont actually need to empty the system
just get the water lower than your pipework repair,

for whats its worth i have always drained the system, as im pretty sure it will have crud in it anyway

Well mine does !!

Steve

why are you shuting valves just drain it below level you want to work at ie open bleeds on upstairs rads........do work...chuck in some inhibitor...........refill............bleed up and away you go........any probs u2u me.............

Assuming that you've got a vented system rather than a sealed one, you could try placing two bungs in the header tank - one in the expansion/feed pipe and one in the vent pipe. Shut off the radiator and drain it. Remove the radiator and drain one pipe into a tub (not much will come out as you've created a vacuum. You can then work on that pipe - do not work on the other or you'll break the vacuum! Plumbers merchants sell the proper bungs for it.

I used the Wickes' one to move a radiator in the living room. Prepared everything first so I had most work done prior to disconnecting the radiator, then used the freezer kit, cut the pipe, cleaned it and used inline quick-fit type compression service valves so I could shut them down to carry on working on the new location for the radiator if necessary. Took me around 10 mins tops and the stuff was still holding fast. Worked a treat.