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how to purge air from my zones.....

jamesdinty Member Posts: 6
Hi....I have what sounds like a river of water gushing when my baseboard heating system is calling (all zones). I suspect I have lots of air in the system. I've watched many videos and read lots of material on how to purge the air and it seems quite simple. However there is one thing I do not understand.............

I have B&G flow control valves on each zone. They are all in the automatic position (lever on top is fully turned clockwise). I assume these will automatically open when I introduce water pressure from the fill valve (similar to what the circulator pump will do in normal operation) but I am not sure. Will I need to open those levers on the flow control valve to properly purge the zone? I hope not because they are stuck.

My process will be as follows:

1) Turn switch to boiler off
2) Close the return valves for each of the 4 zones
3) attach garden hose to one zone at at time and run into 5 gallon bucket
4) open Fast Fill lever and monitor pressure stays below 30
5) run water into bucket until air is purged
6) close fast fill lever
7) close the zone that was just purged
8) repeat above for each zone
9) open all return valves back up and power up boiler to test

Will this work?


  • STEVEusaPA
    STEVEusaPA Member Posts: 4,823
    You shouldn't have to mess with the flow cheks.
    Your method sounds about right, can't tell without pictures.
    What type of air elimination do you have?
    What type of expansion tank do you have?
    After you do all that, run the circulator for a little bit. You may have to repeat.
    If you were pumping away, and had a microbubble reabsorber for air elimination, you would never need to purge again, just keep the proper pressure in the system.
  • jamesdinty
    jamesdinty Member Posts: 6
    Thanks for the feedback Steve. Here is a picture of my system if it helps

  • hot_rod
    hot_rod Member Posts: 14,552
    Zone pumping does create a challenge for "pumping away". Ideally the expansion tanks would connect to the inlet or suction side of the circulators.
    A better air purger may help, but if it has worked fine in the past, you should be able to get back to a quiet system.
    Any changes made in the system recently, pressure dropped for any reason? Pumps changed? What model are those pumps?

    In some cases adding a few psi to the fill pressure will help eliminate air problems. After you do a good purge, of course.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • jamesdinty
    jamesdinty Member Posts: 6
    Thanks Bob......the pumps are taco 007-F3. There have been no recent changes to the system. About 6 years ago I lost heat in one zone due to air. After purging, everything has been fine up until this heating season where it's been very noisy.
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 1,817
    edited January 15
    That Utica Boiler has a built in air scoop design into the casting. The air vent close to what I believe is the fill valve should be left open so the air that accumulates there can be vented. If the vent leaks water then replace it with a working air vent.

    That should also help

    Yours Truly,

    PS. WOW. Really old Taco 007s. Look at the wet rotor housing detail,
    Edward Young
    Retired HVAC Contractor from So. Jersey Shore.
    Cleaned & services first oil heating system at age 16
  • jamesdinty
    jamesdinty Member Posts: 6
    well.....that was a disaster.......I've purged air from this system 6 years ago and had no issues. This time I went thru all 4 zones and tried to fire it up and I get Low Water indicator. I messed up somewhere. Called the HVAC guys to resolve it as it's winter don't want to go without heat for too long.......thanks for the help anyways.
  • jamesdinty
    jamesdinty Member Posts: 6
    I was able to resolve this so I cancelled the service call. All I did was pull out the low water probe, clean it off and re-seat it into the boiler. Problem solved. All is good now. Just not sure why the probe acted up after I purged the system
  • Youngplumber
    Youngplumber Member Posts: 500
    Did you circulate the system with the boiler off for a while before you tried to start it? 
  • jamesdinty
    jamesdinty Member Posts: 6

    Did you circulate the system with the boiler off for a while before you tried to start it? 

    I did not....the low water cutoff was on so the boiler wouldn't start. Are you saying that if I put the zones on to circulate cool water, then the low water cutoff would not have failed?
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