One zone of heating not working, likely airlocked

wardmoberg

Pretty sure I've got this, but would like confirmation.

One zone of 4 on my boiler is not putting out heat. Gas company came out, gave boiler, valves etc. the thumbs up and say they believe the line has air in it and is not flowing. They can't do anything because they are not plumbers. So it's going to be -14 this week, and I have no heat in 1/4 of the house.

I did this many years ago, but would like to confirm what I remember from looking at my system.

Zone feeds, just beyond the zone control valves, with positive stops and drains on each: zone feeds
2.Common return to boiler, with drain valve. common return

If I: a. Shut down boiler. b. Shut positive stops to all zones (orange handles in pic 1). c. Attach drain line to offending zone drain (in pic 1) into bucket of the glycol mix. d. Attach pump to drain line in 2 and feed from glycol bucket. e. open both valves and start pump

I should push glycol up through the return line, through the offending zone and back out it's drain, pushing out air and refilling line.

Correct? Or will I have a problem with the pump in 2 being in the return line I am trying to push the glycol through?

I don't want to screw up my boiler with even colder weather coming, let me know if I am overthinking this or missing anything.

THANKS for any help!

wardmoberg

https://imgur.com/QHltdfq

wardmoberg

JohnNY

Sounds like you got it right.

wardmoberg

THANKS JohnNY! I believe so, but with -14 forecast, I second guess myself. Blame me? Anyone else see a problem with my logic?