Drain down

[bcp]

OK so was chatting to a couple of 'peers' over a drink or two and there was a disagreement. I have to drain down to replace 2 rads and fix a leak from a blown solder joint on the flow / towel rail 22mm-15mm pipe. It's a house. One rad 1st floor, one rad ground floor, leak 1st floor. Mate 1 said you must manually move the 3 way diverter to the CH position. Mate 2 said just drain - forget the diverter, leave it where it is it's irrelevant as you aren't doing any work to the primary circuit.

Discuss and advise please.

 

[Leo21]

The system can airlock on drain down and not drain all the water, that is until you open a pipe up and it all comes gushing out.

 

[Ermintrude]

Put it in mid position and drain

 

[bcp]

Put it in mid position and drain

That's what I'd always done when a freezer was not appropriate. Ta for conf.