I have a 1 pipe steam system. There was no main air vent installed, I think it was plugged. Last year, I have a plumber installed a Gorton 1 main air vent where it was plugged as seen here:
Here is the main pipe:
This is the end of the main pipe and then curve to the left to a raditor and then pic 1. There are 3 risers that feed 2 raditors in the first floor and 4 in the second floor.
My question is, by having the main air vent there at the return, does it serve any purpose? I haven't really noticed. Also, will adding another Gorton 1 with a tee there will help? I have a water hammer problem in my master bedroom. I hear the loud bang once the thermostat reaches the set temp or boiler stop firing. Air vent is changed, radiator is pitched, valve is fully open. Also, my bathroom vent and third bedroom hisses loudly.
A few days ago, I put in Squick to clean the boiler. I haven't drain it out yet. The water glass gauge is filled half way. Water only move at most 3/4" when the boiler is on.
Any ideas what else to check for?