I have a Power Fin M#IBN1500 S#G08H0021048. I am doing the start up on this unit. We have been brought in after the installing contractor had an issue with it (Heat exchanger was twisted and pissing water).
The start up looks good. The bypass is maintaining a 136 degree temp.
My only concern is that the IOM states they are looking for a 3.5" w.c. pressure difference for both air and gas pressure. I have a 4.1" w.c. both for gas and air. I have the 1 to 1 ratio they are looking for but I can't get the pressure any lower even by moving the tube for the low side of the air tube on the burner.