The household comfort provided by your boiler should be felt, not heard. Sounds emanating from a boiler can indicate anything from a minor maintenance issue to a major malfunction. Whatever the source, fixing boiler noises is a job for a qualified HVAC professional. The gas-fired burner flame and the hazards posed by deadly combustion byproducts, like carbon monoxide gas, make boiler diagnosis and repair a professional project.
Anything you can do to cut summer heat buildup in your home will lower your cooling bills immediately and for years to come. It won't cost much, and it will make a big difference in your conditioning load. It could even improve indoor air quality. Your attic, windows and air infiltration are the best places to reduce the heat gain indoors.