Bunging the cold feed and vent

[stratplus]

Whats the point of this when you want to change a rad and re-pipe? All it does is hold the water in the f and e tank. The existing rad pipework drains anyway with the pipework under the floor and when re-filling the system if there is any carp in there this will still drop into the pipework potentially causing a blockage.

 

[Ch4 plumbing]

I've never used it for that purpose, I bung to change rad valves or pump valves or 2/3 port zone valves. If I'm altering pipe work I always drain down.

 

[townfanjon]

toooooo risky !!

 

[stratplus]

I've never used it for that purpose, I bung to change rad valves or pump valves or 2/3 port zone valves. If I'm altering pipe work I always drain down.

Its a pointless exercise when your re-piping cause the heat draws the water down anyway. I bunged one today but there were constant bursts of water coming through and when it came to re-fill all the other rads were empty anyway.

 

[kay-jay]

Whats the point of this when you want to change a rad and re-pipe? All it does is hold the water in the f and e tank. The existing rad pipework drains anyway with the pipework under the floor and when re-filling the system if there is any carp in there this will still drop into the pipework potentially causing a blockage.

ive done it a couple of times.
if done correctly it does more than hold water in the f and e, it creates a vacuum which allows you to work on the system without a drain down.
it is important to only have one open end at a time though otherwise all you will achieve is keeping the f and e full.

so for a valve swap you would close the valves on both sides of the rad, then when you uncouple the valve which needs swapping from the rad you will just get a few dribbles from the rad which can be stopped with another bung or apprentices finger etc as its not under pressure.

then open the valve that is to be changed and is now uncoupled from the rad and allow water to fill a container until the vacuum from the f and e holds. whip the new valve on and jobs a good un

 

[Irish]

Spot on Kay jay

 

[stratplus]

ive done it a couple of times.
if done correctly it does more than hold water in the f and e, it creates a vacuum which allows you to work on the system without a drain down.
it is important to only have one open end at a time though otherwise all you will achieve is keeping the f and e full.

so for a valve swap you would close the valves on both sides of the rad, then when you uncouple the valve which needs swapping from the rad you will just get a few dribbles from the rad which can be stopped with another bung or apprentices finger etc as its not under pressure.

then open the valve that is to be changed and is now uncoupled from the rad and allow water to fill a container until the vacuum from the f and e holds. whip the new valve on and jobs a good un

I had flow and return open together. Thought about doing each separate but never did it.
Bunged the f+e cold outlet and put push fit cap on 15mm vent.

 

[stratplus]

Thankfully didn't have any airlock issues or blockages but it was all 15mm drops and no airjec. The last one I had was microbore and an airjec. When I tried to re-fill it blocked straight away. Ended up taking out the airjec which was completely blocked.

 

[josh]

If i have to drain down an old open vent system i sometimes start draining before tieing up ball/isolating F+E tank and just listen to make sure i can hear it filling to prove to me it's not blocked so when it comes to filling again i wont have that ball ache.

 

[Ermintrude]

Washes the tank clean into system.