Add Spirovent JR

Randge

Folks,
Two seasons of trying to bleed air thru the vent tees on second floor baseboards, I give up.
I had boiler tech come over to purge by running water thru system down drain to no avail and did it my self to no avail.
I wish to try a Spirovent Jr and have only 2 options that I can see after reading many similar posts. In my picture I have shown the piping and trust me, there is no room other than the two options I point out. Yes, I could replumb but hope to get good results without doing so.
If I have read correctly, the return line to bottom of boiler is not best choice. I'm open to that if it's better than option 1 or 2. There is plenty of space to put it there.
I can mount it about 12" above the circulator or 12-15" above the tank.
What's my best bet short of tearing it all out and starting over? Worked well for 10 years and cannot find a leak. Plumber replaced circulator 2 years ago and hasn't been free of air since.
Thank you in advance.
This is all 3/4" copper pipe.

Solid_Fuel_Man

If you move that circulator (labeled pump) to after the expansion tank you will have better luck removing air.

Pumping directly into the tank as it is now is the worst for trying to get air out, pumping away is the best.

I've had pretty much ALL my air problems go away since I've been installing circulators after the expansion tank. Been doing it that way for 8 years now. Once I joined here and really understood what was going on in a closed loop system.

Solid_Fuel_Man

Also, where is your current air elimination auto-vent located? Best place is at the expansion tank location called "the point of no pressure change" or PONPC.

Solid_Fuel_Man

Also you should have a flow check somewhere after the circulator.

Randge

This is in a duplex. There are 2 identical boilers side by side plumbed identically. Obviously the air issue started after pump 😃

Randge

was replaced. Not feasible to replumb now. No auto vents installed. If I’d be wasting time and money putting spirovent at either option 1 or 2, I will keep trying to purge to drain and bleed at vent tees.

hot_rod

or move the expansion tank connection down to the suction side of the circ pump.

Air elimination is best accomplished at the hottest point in the system, in the boiler supply pipe.

What was the previous circ pump? A 3 piece B&G 100 by any chance? Sometimes changing the pump to a different higher velocity type caused chronic air problems, especially when pumping at the tank as you are.

If you are adding a central air purger, mount the circ downstream and connect the expansion tank to the air purger, as SFM suggested. That improves 2 functions, air removal and best pumping practice.