Bleeding air from hydronic loop

Steve Garson_2

I had to replace my  expansion tank.  I’m having trouble getting one loop to flow and would like advice.  I am closing the ball valves for all the loops except the one I need to bleed.  I close the tempering valve on the boiler.  Then open the valve to drain into the hose.  What am I doing incorrectly?

Big Ed_4

Close off the valve going back to the boiler , manual open the zone valve

Steve Garson_2

how long should it take?  I’ve drained 25 gallons and the 2nd floor zone still is cold.

EBEBRATT-Ed

@Steve Garson_2

I can't see all the piping around your boiler but I assume you are purging out through the black hose with the boiler drain valve. If so follow the pipe the hose is on down into the boiler. Shut the valve where it goes into the boiler.

Feed water into the boiler. It should go into the boiler up through the zone back down through the zone valve (manually open the zone valve for the zone your doing) and purge out the hose.

Purge until you get solid water. If you put the other end of your hose in a bucket you will be able to see if you have air bubbles or not

GW

If the water is  steady with no air bubbles, and the zone is still cold, something else is going on. Little bit difficult when we can’t eyeball the entire system in one frame. Little bit difficult to do with the camera. You’re either missing a valve, it’s a “one pipe” (do you have bleeders on the heating elements?), you have a “split loop (missing a valve), or even a simple “back burp” (I know I know but that’s the phrase we use), meaning there’s air hanging right there at the purging area. Or you have more than one zone open. Or, you’re not actually pushing through the zone

I always tell my guys, “if the previous guy purged it, we can too” 
Sometimes basements get finished off and valves get hidden. That would be a problem

Steve Garson_2

Mission accomplished!  Thanks for the advice.