Boiler purging

jeff3176

HELP!!! I recently removed my ancient expansion tank from between the floor joists, and installed an Amtrol EX 30 tank. I installed as per the manufacturer's diagram. I cannot seem to get the air purged from the system. With the system off, I'm attaching a hose to the drain valve, opening the valve, and maintaining pressure by opening the water supply ball valve. I've attached a diagram of how my system is configured. I greatly appreciate any help.
Thanks,
Jeff

neilc

did you check the expansion tank air pressure?
is the air cap loose on the air vent on the air scoop?

purging,
are you closing the ball valves at the circulators, just the one pair, top of circulators,
and you're purging from those left drains above the circs, one at a time (?)
and as that loop stops blowing air, you open the ball valve below, to burp that circ and that line below, burp that ball valve a couple times,
then switch to the other circ loop,

is the system pressure raised up to about 20?
you can go to 25, but don't push 30, or safety valve lets loose,

hot_rod

Pumping at the expansion tank makes air removal tougher. Not impossible with a good separator, maybe a couple high point vents.
What size are the pumps?
Air vents do clog sometimes, do you ever hear air coming out of the vent on the air purger?

EdTheHeaterMan

jeff3176 said:

HELP!!! I recently removed my ancient expansion tank from between the floor joists, and installed an Amtrol EX 30 tank. I installed as per the manufacturer's diagram. I cannot seem to get the air purged from the system. With the system off, I'm attaching a hose to the drain valve, opening the valve, and maintaining pressure by opening the water supply ball valve. I've attached a diagram of how my system is configured. I greatly appreciate any help.
Thanks,
Jeff

There are some clues here that I am picking up on. "my ancient expansion tank"
How old is ancient? 40 years? (when baseboard radiators were being installed). 60 years? (when Monoflo tees and wall mounted convectors were in vogue) over 80 Years? (when gravity systems that are now converted to circulator pump systems were popular)

Only one of those systems are "Purgeable"

AND
"cannot seem to get the air purged"

If you have the one type of radiator that is "purgeable" are you actually forcing the water to take the path to purge the loop? are you using all the water pressure you need?

Im guessing that you may have one of the other designs that is not actually able to be purged.

A picture of a radiator and a picture of the boiler room from 2 or more angles, so we can see the piping arrangement, would make answering your query easier.

HVACNUT

You're purging from the drain valves above the pumps? Are you closing the ball valves above the pumps? I hope so. 
There's no way to purge through the boiler as is but whatever air is in the boiler should hopefully make its way to the air scoop.