Pentair/Sta-Rite Combustion Blower (P/N: 77707-0251)
Fits the Sta-Rite Maxetherm heater 200k btu model
Located in the front top portion of the heater.
Draws combustion air in, mixes the air and gas and forces the air and gas mixture into the burner.
The air orifice attached to the air gas mixer inlet meters the flow of combustion air to the burner.
If your heater is making a hi pitched whistling noise you could have a bad blower.