it shouldn't happen to a plumber........but it does!

[kay-jay]

so bunging the feed isn;'t a problem unless i'm silly enough to bung the vent too?

 

[Twinhawk]

once you bing the tank the static head is then from the top of the cylinder which doesnt need drained, open a tap, .5 bar at most in a 3 story house isnt going to collapse a cylinder, maybe a direct one for heating with the weight of water

 

[kay-jay]

thats what i thought twinhawk, i was querying tamz post from above warning of cylinder collapse.
personally i can't see how it would collapse by using a bung but tamz has been at this game longer than me and i respect much of what he says in his posts.

 

[tamz]

99 times out of 100 you would be fine bunging it but there is the possibility that it can and does happen.

Things to watch for are if there is an essex or surrey flange on the cylinder where it can draw from inside the tank or if there is a pump on the draw off which kicks in.

Just be aware, .🙂