How well does bunging the cold feed and Open vent work

[Matt0029]

Have a radiator to swap. I'm thinking of piping back to the current supplies. The rad is slightly smaller. The connecting on the the old pipes at the end one by one. Would using bungs in the open vent a cold feed create enough of a vacuum for me to do this? Which a drain down. Thanks

 

[Last Plumber]

It can work OK but it depends on the system. You will know pretty quickly whether it is going to be successful or not.
It is worth a try but I wouldn't mess about for more than 15 minutes, if it is not slowing down to what you would experience on a sealed system by then, leave it and drain it or freeze it.
Only my opinion from my own experiences.

 

[Chuck]

Ask 'If the bung did start leaking in the middle of this exercise, how bad would it be?'. If the answer is anything worse than 'Not a problem', I'd recommend draining/freezing.

 

[Matt0029]

It wouldn't be too much of a problem as under the floor. I've never used the bungs before. I know things usual seals off quiet well on a sealed system.

 

[Matt0029]

Have got a freezer rothenberg electrical one

 

[Jerry]

Drain down system.

Wet vacuumn out the pipes if needed.

Fit rad.

Add inhibitor.

Refil

On to the next one.

 

[Matt0029]

Ended up being a one pipe system 😩. I froze it on each leg with the rothenberg turbo electric freezer. Was to be able to solder around 30cm away on. Put a wet grab between soldering area and freezer.

 

[Matt0029]

Had a terrible do once re-filling a vented micro bore system. But I think micro bore on vented are ment to be hard work all the time