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I have a question about the location of one of my main vents. I've attached the picture of its location. The steam comes from the left and there are 3 pipes go up to the radiators that are not on the picture. The pipes are 2" and about 41 feet long.
Does this vent work properly on that branch?
The problem I'm trying to solve is :
1. my boiler runs a few cycles to maintain the temperature. Every cycle the vent on radiator start to hiss and release some air (hot). Other vents stay closed including that Gorton on the picture.
2. after thermostat shut off the boiler, about 1 minute later, this vent and another vent on second floor, start to suck the air into the system.
I'm wondering if it's a problem with the main vent location/size or bad vents?