Best Of

And do combustion test after modifying burners.

You need to fix the near boiler piping. By doing what he is doing is just praying he gets the whistling down to an acceptable level to which you will agree to. Even if he can satisfy you by doing what he is doing You will still going to have high fuel bills. there is no way around it. Basements with steam boilers are always warm even insulated but having copper piping on your boiler is only going to increase the heat into the basement. Never mind the wet steam its going to generate.

And considering the manufacturer and there castings issues i would definitely get the piping changed. I don't know how anybody else feels but i wouldn't service this boiler or any boiler unless the near boiler piping was properly installed. I don't need a customer blaming me for some noise or leak that was happening before I got there but they didn't notice it until after i worked on it. I've done enough PM's on Burnham's that the first thing i do is flood them.

I think it's also useful for the OP to understand, steam, when running properly, should be silent. You shouldn't hear a bang, creak, groan, nothing but warmth. I'd say at most maybe a hair of air "noise" from a vent, but it would be at the level that you'd have to catch it in the act and listen carefully, not screaming as they state.

I think steam gets a bad reputation as making noise in some way. I think it's valuable for the OP to understand what the expectation is, and that is essentially, silence.