Hayward 250

[scent of a mule]

I have a Hayward 250 Natural gas heater. About a month ago it started popping when turned on. The pops get so forcefull that the above ground pipes move with each bang. I am sort of a novice and figured maybe air was in the lines and expanding. I have tried to configure every flow change possible to see if that would help or eliminate the problem. It doesn't matter if it is configured in spa mode or pool mode.

Any help?

 

[4JawChuck]

It might be the pressure switch cycling on and off which causes the flame to cut in and out when the igniter tries to light once it "sees" pressure. You can bypass the pressure switch with a jumper wire to determine if its the cause.