Boiler Air Purge Check

[cs2kplus]

I no very little about boilers. However...Ive see that it is simple to check for air in lines on a boiler. Just hook a short hose to the right valve and release into a bucket. My proble is....I am not sure which valve. One is blue on top and one is read on bottom. I bet its the red. See picks. Oh...I also saw in a video that you can have furnace running while doing this.

 

[Tom Sawyer]

Neither one.

 

[Sponsor]

 

[Dana]

Most systems will have air relief valves on at least some of the radiators or baseboards. Air tends to collect near the highest elevations of the system, and that's usually the best place to bleed the system to purge air, when you can.

Most systems also have vents to release bubbles, often at a device designed for trapping those bubbles.

Baseboard air bleeder valve:

Air bleeder on a radiator:
Air vent on a boiler:

Air vent on an air-scoop device:

 

[cs2kplus]

Sorry, I never answered this. I don't think I ever got email. I was told about the bleeders on the baseboards and after the expansion tank. But I thought flushing with water was the way to do it? I just posted another thread with a diagram. Seems easy on a one zone? But I will look for bleeders on baseboard. I do have bleeder per pic shown above after expansion tank. Thanks!