I have purged out the air from my boiler a month ago.Now, there is vibrating noise inside the boiler and the pipes, when the burners turn on. The noise stops, when the burners shut off, even if the circulators are running.It is a forced hot water boiler, runs on gas. Laars Mini Therm.
This sounds like kettaling this is where the water is boiling inside the boiler (i know it sounds strange ) this will cause what sounds like a kettle being boiled and will cause vibration in the pipes The fix may be as easy as adding a solution to the water in the heating side or bleeding your radiators also turn the temp down on the boiler (not the thermostat for the rooms ) Failing this a new heat exchanger may be needed in the boiler
