Popping noise on startup and noise gas valve?

Steve Nichols

Hey all,  I have a new Burnham 5SIN gas  steam boiler, installed 10/12.  I have recently noticed that upon startup of the boiler, I can hear "popping" sounds coming from the boiler itself.  It goes away in about a minute.  I am one of the individuals who started using the Steammaster tablets a couple of months ago and I am wondering if the chemicals are causing the rust/dirt to clump at the bottom of the boiler, potentially causing the noise?  Chris, Gerry, any thoughts on this?  I'll probably drain the water and try running a bit with "straight" water and see what happens.

Second concern, when Tstat calls for heat, I can hear the vent damper open and then I can hear two separate "thunks" that I can trace to the gas valve opening.  Mind you, I have my "office" located directly above the boiler.  I have put rubber around the places where the pipe goes through the hangars and it's cut down on the noise a bit.  Is this noise normal?

Thanks again!