Utica boiler bleed question

I have a 20 year old Utica boiler. I had a boiler inspection done by my utility company and the guy recommended that a system bleed be done. When I turn my heat on, I hear water running around the room with gurgling sound. The sound goes away in 10 secs. It is quiet after that. I am thinking it is not a critical issue, but I would like to do the bleed before winter starts.

I read a few posts about purge/bleed. But I understand that each system is a little different. So, I am trying to find out how do I bleed the boiler? Please include as much detail as you can.

I don't know enough about the boiler to describe it, so I am attaching a few pictures. There is also a comressor with hy-vent that I don't have picture of.













Thanks a lot.

 

We need some pictures of the overall piping layout. Stand back farther and let's see the stuff up toward the ceiling. There are probably some flow-checks and/or other valves up there. The Hy-Vent may be the source of the problem, if it is clogged up and no longer working. Given the stains and corrosion in the pictures, I'd venture that is a good possibility.

It's also possible that you have manual bleed valves at the ends of your baseboard (or whatever heat emitters are in the house). Bleeding those is pretty simple.

As an aside, you might consider replacing those three dinosaur circulators. New ones use so much less electricity that they'd pay for themselves in 1 (maybe 2) heating seasons.

 

Thanks xiphias or your response.Here are a few more pictures.

I don't think I have manual bleed valves at the ends of the baseboards. Now if you think that the problem is with the hy-vent, how can I replace it?

thanks a lot.