I have 10 year old boiler with hydro air with anti freeze in the heat loops. I keep getting air in the system every year ! why is this happening. Bob

Bob, January 2012

With anti-freeze they usually shut off auto-feeds and auto air bleeds.Feeds because don't want to degrade anti-freeze and bleeds because crude grows in such places.Strength of anti-freeze needs to be checked now and then asked techs.for best advice.

Old Guy, January 2012