Hayward H100ID Heater Popping and Shaking

[tbone23]

Good Afternoon! I have a 15x33 agp with a 20" Hayward Sand Filter and 1.5hp Powerflo Matrix Pump. Everything Works great!! I hooked up a Hayward H100ID 100k BTU Propane Pool Heater.
Shortly after I start the heater I hear a popping and the inlet PVC shakes sporadically coming from my sand filter. The Outlet PVC does not. There is no bypass. It is running directly through the heater. I had the heater running for about 3 hours. Doesn't seem like it is heating the water correctly. Any advice is much appreciated.

 

[borjis]

Any chance the inlet / outlets were swapped?
Water flowing in reverse?

 

[tbone23]

No, everything is hooked up correctly.

 

[danpik]

Are you running the pump on the highest setting? These have a tendency to boil water in the heat exchanger if the flow is low. However, the if the flow is too low the pressure switch won't allow it to come on. You might be right on the edge of that though.
Not sure what you are expecting when you state it seems like it is not heating the water correctly

 

[tbone23]

Are you running the pump on the highest setting? These have a tendency to boil water in the heat exchanger if the flow is low. However, the if the flow is too low the pressure switch won't allow it to come on. You might be right on the edge of that though.
Not sure what you are expecting when you state it seems like it is not heating the water correctly

Yes, I am using a Powerflo Hayward Matrix 1.5hp pump. The pressure seems great! From what I have read, there is a stainless baffle on the outlet side of manifold that keeps lifting. The fix is to take a stainless steel 3/8" rod and jam it in to hold the baffle down. Seems like I should just buy a new heater lol.