Steam boiler heating problems.. need help!!

Oh my gosh. We've seen so many boiler installs these past few weeks where the near boiler piping is just a mess, as is yours. I don't see a proper header, that copper is going to give way at the solder joints at some point in time. Copper is ok below the water line but not above it because of the amount of expansion/contraction. None the less, I see at least one main vent tilted at about 45 degrees. Aside from that not being nearly enough venting, that vent can't work properly unless it is setting vertically. It is likely stuck closed. You say you traded out some straight vents for angled ones. How did you install the angled ones? on an elbow? They can't work if they are laying horizontally either. When you say 3 convectors are tied to thee return piping do you mean the main turns and heads back to the boiler? That would still be the Main. The return piping would begin after the last convector supply line. There should be Main vents on both mains, somewhere after the last convector supply run and it has to be suffecient to evacuate the air and move the steam as quickly as possible. do you see any plugs that might indicate a vent was removed from the second main? To determine the number/size of main vents required, we need to know the length and diameter of each main. They we can advise you on that. It doesn't look like you have insulation on a good amount of those mains and it even looks like one may run through a garage. Those mains need to be insulated to keep the steam from condensing prematurely until it gets those pipes hot enough to sustain enough steam to get to the convectors. I don't believe this problem began after just changing out the Pressuretrol. Has it been a problem for a long time or has something else changed recently?

Looks like 2 inch mains at 30 feet long, you need to vent .69 cubic feet of air out of each main. You need 2 gorton #1's on each of those mains. A Gorton #2 would work well but I don't think you have the headroom as they are fairly large. If you could take that Maid-o-mist that is at an angle out and add a 45 degree street elbow in that taping, then you could build yourself an antler with a couple short nipples, one Tee and one 90 degree elbow and put 2 gorton #1's on it or if you like the Maid-o-mist, you could just mount a second one of those on there. They vent at the same rate as the Gorton #1's. i'm not sure that's going to fix your problem though. If the system heated ok last year, and you made no other changes, something else is going on. What was the old Pressuretrol set at, Cut-in and Differential? It may be they had the pressure set much higher to try to compensate for some of the piping issues. Not good but maybe it was a "Band aid".