Draining my microbore rads

22 Feb 2009
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United Kingdom
Hi All,

All my rads are connected via microbore copper pipe to a 22mm manifold. The lockshield valves on the downstairs rads all have a drain facility as you'd expect, but I have two questions:

1. When draining the whole system, am I right in thinking that I should drain via whichever lockshield valve drain point is most convenient, then drain whichever individual rads I need to work on?

2. My LSV's all look like this:

How do I open the valve AND connect a hose when the drain point looks like that? I don't mind a few drops of water but I really don't want to risk spewing central heating gunk all over the hallway if I'm not fast enough to fit a hose and tighten the hose clip! Any suggestions?


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its a bit of a pain but you see the end of the valve where that square shape is situated. use a rad key to undo this, anti clockwise to open it and stick a garden hose on it immediatly and this will drain the system. if you just want to drain a single rad just turn both valves of either side of rad and undo to unions and drain the rad.
Damn they look like nasty awkward drain offs {>.<}

Yep, they sure are. I was hoping that there was some clever technique but I've got a feeling that there isn't - I'm just going to have to be quick.

The problem I can see is that the square bit that you open up with the rad key actually comes out completely. That means that I have to undo it all the way then remove it before I can put the hose on! I'd have to be superman to do that before a couple of gallons of cr*p cover my hallway.
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Actually, I've just had a thought. If I temporarily block the downpipe from the header tank with a bung, that should create enough of a vacuum for me to fit the hose. Do I need to block the expansion pipe as well?
look like myson matchmates, a normal garden hose will **** out, you need to take the screw out of the middle (with a rad vent key) and get a hose on quick (smaller than hosepiupe size tho)
Just Thinking out loud....

It's got me thinking of a variation of (ChrisR's IIRC ?) method of dealing with draincock washers.

Get another bleed valve key, remove the Tee handle and hacksaw a slot in the top.

Loosen the valve with an unmodified key.

Put your modified key onto ther valve, and fit your hose over the outlet and your key.

Push a small screwdriver through one side of the hose to engage the slot you cut in your modified key and unscrew valve. Leave the screwdriver in place to stop your key and the valve disappearing off up your hosepipe.
yeah block cold feed and open vent to create a vacum. it may take up to a gallon of water removed to create or just a pint

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