Burping Hot Water Heating Boiler
Hello All –
I’m replacing a waterlogged – failed – expansion tank on my domestic hot waer heating system; but, I need help learning how to vent air from the system once the tank’s installed.
I’ve got a garden variety system -with four zones and two circulators. Piping from boiler to each zone has a shut off valve with a hose bib downstream of each shutoff. Makeup water is fed to the boiler via a pressure reducing valve set at 12 psi.
Now i’d love to learn how to purge the air from each zone. Any how-to help is most appreciated.
Walter D
Weston CT
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Replies
purge device, I believe
Just a note of clarification: the domestic water system is that which provides potable water to household fixtures. Not a heating system.
To answer your question - how to get the air out.
Option 1 - assuming your system has an air separator and is piped in some normal fashion, turning it on and let it go, make sure to cycle each zone a few times.
Option 2 - assuming your system has high point and/or terminal vents, fill up and pressurize the system and go open every vent until water comes out. Start at the highest point in the system and work your way down. Start it up, cycle the zones, repeat.
Option 3 - if your system has no air separator, find a competent heating professional to straighten out your system. The system should have an air separator, with a vent, on the hot water supply (the pipe coming out of the boiler, providing hot water to the loads). It is common that the expansion tank be connected to the bottom of this device. Usually, the air separator is between the boiler and the circulator(s).