How do I bleed my hot water baseboard heating system correctly?

[Zack1978]

HI everyone,
Seemingly out of nowhere air has infiltrated my hot water baseboard heating system, powered by an oil furnace. When the heat kicks on, it sounds like I am on a boat in the middle of the ocean....all I hear is water rushing.
I posted a picture below that show the two valves that I believe are used for bleeding air. I used these two valves last week, and it did nothing. The steps that I used were as follows:

1. Connect the garden hose to the first valve, and move the knob on the valve into a horizontal position, then open the valve. I put the hose into a bucket and there was air bubbling out, so I ran it until I didn't see anymore bubbles. I did the exact same thing for the valve on the other side. I then returned the knobs to the vertical position when I was done. The process that I used did nothing at all, and it sounds just as bad.

Should the heat be on or off when I attempt to bleed the system?

Since the air seemingly came out of nowhere, could some part have failed? If so, what part might it be?

Also the second picture posted is the air valve, when you depress the schrader valve at the top you get water out.

Any ideas?

Thanks,
Zack

 

[Koffer]

those valves are not going to help you at all , you need to look for a bleeder valve at the highest point in each ckt.

should look like this with a set screw in it

 

[Zack1978]

those valves are not going to help you at all , you need to look for a bleeder valve at the highest point in each ckt.

should look like this with a set screw in it

Hmm....I don't think valves like you pictured are anywhere to be found in my house. Any other ideas?


Thanks,
Zack

 

[Toyo FJ40]

The purge setup you have should work just as you did it but you must maintain 15 to 20 psi in the system as you do it.
A boiler auto fill usually won't add water fast enough to purge the air out. You need to look for a lever on the auto fill that you can flip up or a valve that bypasses the auto fill and puts water into the system. Probably the valve on the 1/2 pipe in your first picture.
When your done leave the system at 12 to 15 psi.

Air can enter the system through the air vent in your second picture if the pressure is to low.