Pick the brand
The brand is printed on the same plate as the model number.
Parts that come up most
The part numbers listed for the most heating and cooling units in the index. Open one to see every model it fits.

HT01CN241Central air conditioner air handler transformer10 heating and cooling units
HK61EA006Central air conditioner air handler fan control board9 heating and cooling units
50DK407030Burner8 heating and cooling units
L99H008Element6 heating and cooling units
58MV660002Blower6 heating and cooling units
CAP050300440RSPCapacitor 305 heating and cooling units
B1086756SFan blade, 15 heating and cooling units
HK42FZ035Control board5 heating and cooling units
HC35GE235Central air conditioner condenser fan motor5 heating and cooling units
317659-405Central air conditioner air handler air filter4 heating and cooling units
B13400-313Central air conditioner condenser fan motor, 1/5-hp4 heating and cooling units
B13400312SMotor4 heating and cooling unitsWhere the model number is
On heating and cooling units, the plate or sticker sits in one of a few places.
Heating and cooling units: Remove the access panel: the label is inside the unit.