Electric pipe freezer

[steve777]

hi

i have got 20 trvs to fit in an office (about 40 rads on sealed system). i have today hired a pipe freezer for the first time thinking i could isolate one area at a time to save the whole building being cold. it seems though that the ice plug cannot hold the pressure in the system. i have frozen a 22mm pipe leading to 3 rads (which i switched off and cooled first) but the water wouldnt stop coming! is that how it is and they can only be used on low pressure pipework

many thanks

 

[linkyplumb]

I have used them on pressurised systems before, with no problems.
Maybe the freezer is not freezing properly.
You could try wrapping wet cloths around the pipe, by the freeze head to aid in the freezing process.
It might be a case that you have to do each rad one at a time

 

[swbjackson]

Where the lockshields all turned off fully? I've frozen an inch rising main with mine before so no problem with pressure.

 

[footprints]

I used to use the large gas bottle freezers and found they worked every time on mains which as swjackson says is high pressure, but I quite often found it did not work on heating pipes even if the system was stone cold.
I came to the conclusion that perhaps additives in the system might be acting as a sort of anti-freeze.
Regards,
footprints

 

[Boilerman2]

You may find the problem is down to the Water Treatment in the circulating water - there are many diffrent Chemicals used to treat commercial systems, many will reduce the freeze temperature preventing a freezer from making a plug (we had this problem in a South London Church last year Aldous & Stamp ltd chemicals were preventing the system freezing

Have a look around the system it is common for isolation valves to be fitted to the F&R's usually at the main riser through the building, find these and you won't need to freeze or drain!!

 

[DaleRCL]

Are you trying to freeze it while the system is still running?