I have a crown aruba gas fired boiler converted to LP. This is an older model maybe 12 years. Intermitently when the boiler fires up I have noise and turbulance in the burner . It seems to always be in the same burmer set . Now I can get it to stop by adjusting the air shutter , but then the flame is way out of wack very yellow. The pressure regulator(Honeywell) has an adjustment screw but it does not seen to help.I thought I could lower the pressure and that would fix the problem. No luck. Could it possibly be that the regulator on the LP tank is shot? This is about 12 years old as are the tanks. There are times when it lights off fine but most of the time I get this turbulance. I am not going to fool with this myself ,but I would like to get educated so I don’t get ripped off. Thanks RDB