Heating, Air Conditioning, Fridge, HVAC/Air elimination


I have an old boiler system original to my house, which was built in 1967.  There are three zones in the house, each controlled with their own zone pump.  It is a closed system with no air bleeder valves, air scoops, or other.  When air needs bled from the system, each zone needs flushed separately, which eliminates the air temporarily, but eventually air starts to accumulate in the system again.

I wanted to install an air scoop on the system, but the supply line runs vertically then T's off into each zone. I believe I would need to re-route the supply line to a horizontal position and re-plumb the zones, which is more than I wish to do on an old system.  Which leads me to my question.  

Is it common practice to place Air Separators on each zone separately to eliminate air?  If so, would the best location be at the highpoint of the system just after it T's off to the zone?  I also noticed that air separators slow down the flow rate of the water, some around 6 GPM.  Is this still sufficient flow to sustain heat in the baseboards.

Thank you for your time.

6 gpm flow should not be a problem.  Use microbubble air eliminators.  You must use a diaphragm type expansion tank with these air eliminators.  any location that is in accord with the manufacturers recommendations should work.  More than one is not a problem.

Heating, Air Conditioning, Fridge, HVAC

All Answers

Answers by Expert:

Ask Experts


Mike Reavis


Questions related to "Wet Heat". This is heating your home, office etc. with radiators, panels, and convector apparatus. Steam and water heat. I can answer questions about boilers, piping,and associated parts of these systems. Please do not ask for specific information about how I feel about one boiler, etc. over another--These questions should be directed to a licensed contractor that you know of, or that your neighbors and colleagues look to to provide solutions.


I have 20 plus years experience, which has lead to passing my state master HVAC license.


Completed college

Past/Present Clients
I work on the manufacturer's side of the business currently

©2017 About.com. All rights reserved.