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Air in system ?

glenn g.
glenn g. Member Posts: 1
I have an old house with a monoflow system (oil/hot water).Everyear around this time I bleed the radiators (old style cabinet type with a damper on a chain, 1/4 square bleeders) and I'll be good for the season. The problem is the radiators on the 2nd floor. I've tried bleeding them several nights in a row and literally get nothing out of them (air or water). I installed a new expansion tank and air scoop several years ago. Any help help would be warmly appreciated. Thanks


  • Brad White_203
    Brad White_203 Member Posts: 506
    Where is

    the expansion tank connection point relative to the circulator? It should be on the inlet (suction) side.

    You also need to increase (or at least verify) your water pressure is at least 12 PSI at the boiler. This will give you 4-5 PSI at the top of the system as a cushion. There is another disquietingly similar post nearby on this topic.

    My gawd, it is a pandemic!

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