Mystery. Need trouble shooting ideas

Stewy2

Couple years ago (2008) I redid my steam system. Real beauty, and very proud of my work. Did the drop loop header, 6 Gorton vents on each main, skimmed it until the water barely moved in the sight glass. She WAS running GREAT. She heat well. Was almost silent. And gas bills didn't leave me looking for a second job (even with the heat on 68). Now here comes the mystery. I go outta town for a holiday vacation and when I come home I can't sleep at night. It sounds like I have a half dozen tea kettles at the point just before they whistle, everytime the heat kicks on. Only one radiator triggers the mechanism in the radiator vent to close it, the others stay open as air bellows out. HELP ME OUT HERE WHAT AM I LOOKING FOR. What could have happened in a week that caused this?@

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nicholas bonham-carter

6 tea kettles

what pressure, in ounces are you showing as the air is escaping? do the vents ever close? have you checked the pigtail for a blockage, which could have raised the pressure? is the pressuretrol linkage binding somehow?

when you take off the main vents, can you blow through them? do they close when steam hits them?--nbc

jpf321

also ..

did you do anything special/out-of-the-ordinary to prepare for your trip .. like turn the t-stat down to 50 while you were away? i'm not sure why it wold matter .. but please provide as much detail about any changes as possible .. i'm liking NBC's thought about the pigtail getting clogged coincidentally with your trip.