[Dornier]

I have an older Carrier 58PB furnace.

The original limit switch is a L4064W------ model.

There are a few floating around, but I went with the official replacement part number from Honeywell, the L4046B----- because I found literature and it was cheaper.

Upon inspection of my older limit switch I see it has two additional yellow lines leading from the center of the switch, just below the dial:

One goes to the big board at the other end of my unit, and one appears to lead into what looks like the smaller of two transformers in the same box that shares space with the limit switch.


The new switch's literature doesn't mention anything but 4 connections.


Am I missing something, or did I simply get the wrong switch?

I have 3 images here to review. You can tell which is which I'm sure.

 

[beenthere]

Wrong fan limit. You need the L4064W, so your blower starts when it should.

 

[yuri]

Yeah, the 2 wires are for a timer to start the fan quicker or else the furnace will overheat.

 

[Dornier]

Well, repair clinic had that Model listed as the replacement.

I agree, needs the connections. Oh well.