Replace rad valve without draining down?

[Hubcap]

Looks like electric freezer is the way to go. With bungs as back up. Several answers have mentioned AAVs what are they - automatic air valves? And what do I need to look out for? Thank you

 

[pobsdad]

Make sure your phone is close by with a plumber on speed dial,just in case!

 

[Hubcap]

Thanks Pobsdad. If there is a problem, the system will have drained down by the time a plumber gets here though. Any advice on what an AAV is and why I should be concerned would still be welcome though.

 

[Billy Bob Bob]

Thanks Pobsdad. If there is a problem, the system will have drained down by the time a plumber gets here though. Any advice on what an AAV is and why I should be concerned would still be welcome though.

aav }automatic air valve its used for filling and draining a system

 

[PlumbBobBob]

if you have any fitted you have to close them otherwise you wont get a vacuum when you bung the small f&e tank to change the trv.

 

[Best]

Sometimes the bung won't seal off some of the fittings in the expansion tank, - I had to do one last week using a dowel I had tapered off with a knife & some ptfe tape around it.
Often no need to drain rad (do drain it if you find it easier) as I just push a little piece rag in tail. Even if tail is different & has to be changed, I use the rag, change valve first, then have the new tail already done with ptfe & a little paste, & screw new one in, keeping a rag in it too.

 

[Old Account]

Hello all, I have got such job too tomorrow and I would like to ask if I bung those fed tanks off, how can you put them in without sucktion ?

 

[Best]

Hello all, I have got such job too tomorrow and I would like to ask if I bung those fed tanks off, how can you put them in without sucktion ?

Suction?? You just need to put a stopend (push fit) on the heating vent and shove a rubber bung into the fed pipe tank fitting inside the f&e tank. Twist the bung as you push it in. Sometimes it may not seal well. Don't worry about suction because it will hold in place and there will be suction later on it once you take the remaining pressure off the system.
Do make sure all auto vents are closed off, or they will prevent the system being sealed.
Take your time at a handy valve to see if water stops flowing.

 

[Old Account]

Suction?? You just need to put a stopend (push fit) on the heating vent and shove a rubber bung into the fed pipe tank fitting inside the f&e tank. Twist the bung as you push it in. Sometimes it may not seal well. Don't worry about suction because it will hold in place and there will be suction later on it once you take the remaining pressure off the system.
Do make sure all auto vents are closed off, or they will prevent the system being sealed.
Take your time at a handy valve to see if water stops flowing.

Thank you buddy I just thought I'll need suction to get those bungs proper into the pipe. I'll take my time I don't rush work don't want to mess about. Appreciate you advise

 

[lame plumber]

ha ha, dont rush, if your happy them bungs wont fall out.... my sphincter always goes tight using them, dont know why, never does it when I freeze pipes with the leccie freezer