Air Flow Sensor - 3 Variations
1998 - Present
PLUG Type Connection
1993 - 1997
PIN Type Connection
There are 3 different air flow sensor part numbers. The 3 variations are the same except for the connector type, wire length, and length of clear tubing included.
4074EZB (plug connector):
All F300 series
F50F F52F F58F series two 1998 to present
4074ETH (4 pin connectors):
F50F F52F F58F series one 1993 to 1997
4074EHJ (4 pin connectors and shorter wires)
F50F series one (single cell model only)
In 1998 Honeywell introduced the series 2 that simplified connections with modular plugs. The AFS was redesigned with a modular plug. The power supply was redesigned with both a plug connector and the pin connectors for backward compatibility.
The F300 and F50F series 2 are manufactured using the plug connector AFS. But some Honeywell manuals will list the pin connector AFS as the replacement. This is to reduce distributor inventory, we don't settle for less.
The pin connector AFS will connect to all power supplies. The plug connector AFS will only connect to power supplies after 1998. To eliminate cross wring problems use the plug connector AFS if your power supply is equipped with the plug connector.
If you are replacing the power supply and AFS, you should use the AFS with the plug connector. Also use the plug connector AFS if your power supply has been replaced after 1998. The TechNote below shows a photo of the compatible power supply.
The 4074EHJ is only used in the single cell F300 F50F model. This AFS has pin connectors and shorter wires. The 4074EHJ comes with 7" of 1/4" OD tubing.