Three way motorised valve

[Malcolm Durnford]

I need to change the three way motorised valve (complete), but looking at the downstairs radiators none have a drain down takeoff.

the central heating system is an old fashioned open non-pressurised one and I wondered if I can use rubber bungs in the feed and expansion tank in the loft (one bung in the tank where water goes into the system and would the other go to the vent pipe which I believe is the open copper pipe sitting above the tank?

 

[terryplumb]

What is your goal in bunging the outlet and vent pipe of the F&E. Is it to avoid draining down ?

 

[Malcolm Durnford]

Yes, pretty much

 

[terryplumb]

My advice to you would be to drain the system ,at least to a lower level than the 3 port valve.

 

[Malcolm Durnford]

No worries- I will purchase a self-cutting drain cock to put on one of the lower radiator pipes.’

 

[terryplumb]

Those things tend to leave the bit of pipe that gets cut ,inside the pipe !! I wouldn't do that either !!
Where is the boiler ,any drain cock there ?

 

[Malcolm Durnford]

I will take a look, the boiler is down under the stairs