How can I find (and test) my steam system main vent?

ethicalpaul

https://forum.heatinghelp.com/discussion/comment/1816515#Comment_1816515

not muscle to spin it faster, left arm muscle to push the jaw into the pipe. It’s a thing you get the feeling of. It’s no doubt hard to learn while holding a 24” steel wrench over your head. If you’re in NJ I can teach you

CoachBoilermaker

Got the wrench to bite, but could not get barely any leverage while on a step stool, reaching above shoulders, and other pipes in the way of wrench handle. Or I'm just too weak. Or pipe is 100 years stuck. I guess I'll call a professional