Help Identify This Furnace Component

[nwav8tor]

Just had my home furnace serviced today (preventive maintenance service contract) and the technician was stumped regarding a component he couldn't identify! He thought it might be some sort of flame sensor since he didn't find one elsewhere, but it didn't look like any flame sensors he was used to seeing. The furnace is a 20 year-old NG Trane model TUE100A948A. The component is mounted under one of the burned tubes and attached to the ignitor assembly. In the first picture you can hopefully see the black plastic module with three white wires going to it. It's attached to the ignitor that's mounted to the "unknown" module at about a 45 degree incline with two more white wires going to it. The second picture is of a sticker inside the furnace that shows the relationship of the burner, ignitor and the "unknown" module (red arrow points to the module). The third picture shows the connector in the lower right corner of the circuit board where the three white wires from the "unknown" module run to.

Can anybody identify this mystery module?

Thanks,
Paul

 

[Rockhead261]

That's an old radiant sensor, perhaps the last functioning one (provided it works). Most of them failed early and got retrofitted with a common stick flame sensor.

 

[nwav8tor]

Thanks RockHead. So am I correct to assume it serves the same function as a flame sensor? And yes, it still is working fine!

 

[Rockhead261]

So am I correct to assume it serves the same function as a flame sensor?

Yep.

 

[atfulldraw]

Rockhead is on it

retrofit is KIT09660

I think -- it's been a few years, but I did the same in one of my rental units.

 

[nwav8tor]

Thanks Guys!! I'll call the "tech" back and let him know. Thanks to you, an old dog can teach a young pup a thing or two...