tl;dr is it possible there's gunk inside blocking the pressuretrol port, even if I can't see it?
Hi - Burnham steam single pipe system, 3rd fl apt. After turning up tstat, fires up, takes about 10-15 minutes to start getting radiators warm; good and hot after 20-30 min. Boiler running this whole time. By 40 min or so, steam is angrily pushing through the radiator vents; the pressuretrol still isn't shutting down the system. I would think it should be by this point? The pressure gauge (separate port from the trol) gets up to 4.5 lbs, which I understand is way too high, if it's accurate. It's somewhat suspect though because it sits around 3 lbs when cold. I tried to remove it to inspect, but can't get a good grip on it with the wrench I had, and/or it's too rusted into place? I replaced the pressuretrol ($220!), but the new one acts the same
. I have it set to 1lb cut in, 1lb differential, just like the old one was. I cleaned out the pigtail; I think it's steel, and I tried to replace w brass, but the one I got was too short. But water runs very well through the pigtail now, so it seems pretty good.
I'd like to get a working gauge; I'd like to put a lower range gauge on the same pigtail as the pressuretrol too, to help me understand what's going on. But right now, I'm trying to figure out where the problem lies. How possible is it that there's gunk blocking the port for the pressuretrol somehow? The port is slightly higher than the top of the sight glass; the water level is about 3/4 up the glass. I know it got overfilled at some point a few years ago because the sight glass connections were plugged up with goo. I've cleaned those out, and the pigtail before as well. This time, when I took off the pigtail, expecting that to be the problem (it wasn't great but it also wasn't nearly as bad as when I cleaned it a year or two ago), I did look a little in the port, and didn't see anything obvious. Should I be more agressive in seeing how that looks in there? I'm afraid to poke too much without knowing it's ok. I've heard it's somewhat normal to have some gunk in the boiler, but does this sound beyond the normal range?