22mm washing machine self piercing taps?

[GaryinAshby]

A friend of mine has a sealed heating system which needs draining but whoever installed the system didn't install a drain valve anywhere. The pipework is 22mm and an obvious "quick fix" would be to use a washing machine self piercing tap to drain the system but all the ones available are for 15mm.

ANyone know if anything is available for 22mm?

Thanks

 

[linkyplumb]

The tails to the radiators are most likely (normally) 15 mm.

You can buy self cutting screw on drain cocks.

Try here:
http://www.bes.co.uk/

page 100

Graham

 

[kevplumb]

then while you have it drained cut a 22/22/15 tee in and a drain tap

as you will find self cutting stuff is carp

 

[TicklyT]

Shut both valves on one rad. and undo one valve connection to that rad.
Drain the rad. into a paint tray / dustpan / bucket, then connect your hose to that valve to drain the system.

Then replace the rad valve with one incorporating a drain cock