draining and filling ch system

[pritsuk2002]

hi i am wanting to drain my system i have a britony combi 100. i have 2 drain cocks downstairs. i shall use both to drain i shall open 1 first with a hose connected to it then, when nothing more comes out i shall go go the other cock and drain that. the questio i have is

1. on drain cock do i turn the square bit all the way open or just enough to let water pass. see im not sure if the square thing will screw out all the way and come off and let water everywhere, or if it stops after few turns.

2. i dont have any rads connected at the moment. i will have 7 when all connected, 1 of them is a towel rail. i herd that i need to open the bleed valve upstairs when draining however i can not do this as no rads connected. how can i drain the system making sure all the water is out without the bleed valve?

A.could i open the flow and return valves on the rad pipes in any of the upstairs rooms.

B if so great, do i need to do this process to every room upstairs that has rad connection to the system? or just 1?

 

[hibeealex]

Well its a bot of a guess, but if you have 2 drain cocks and no rads it may be there's a drain on both flow and return, yes this can be acjhieved by opening the valves anything to let air in to replace the water coming out

the square bit will unscrew fullly if you want but best to leave it in a little bit just so you where it is, or else you might misplace it somewhere,