How to drain 1 zone on radiator

[Daveclink]

I need to drain 1 zone out of 4 to work on a radiator

each zone has a supply and return shut off with only 1 drain for the whole system

Can I drain the 1 zone without draining the whole system?

Thank you

Dave

[Dana]

Sure, but if it doesn't have it's own drain "inside" the section between the isolation valves you'll have to crack it open at a fitting to do that, and it may not be in the most convenient spot from a water-disposal point of view. Figuring out how to fill it without introducing a slug of air into the system may take some forethought too.

[Daveclink]

Thanks for the input. It sounds like it will be easier to drain the entire system and fill the 3 zones leaving the 1 zone drained so I can work on the radiator.

Is the following the correct procedure:

turn up the heat in all zones for about 10 min

1. turn the boiler off
2. close the water supply line to the boiler
3. attach hose to drain and drain the system
4. close the valve to the zone I want to work on.
5. open the water supply line to the boiler.
6. turn on the boiler

I'm sure I'm missing something

Thanks again

Dave

[Dana]

In general it's easier to just drain the one zone if you can figure out where to crack it open. Draining the whole system introduces air and corrosive oxygenated water into the system- treat the "dead" boiler system water as if it were precious!