On Sat, 9 Jan 2021 16:45:31 -0600, bud-- posted for all of us to digest...


There is a device on some systems that removes air from the circulating
water and sends it to the expansion tank.


They are called air scoops and they send the air to the hi-vent which is a
little brass can that vents air. The air scoop could never make enough pressure
to vent to the expansion tank.

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Tekkie