Carrier Furnace (1985) No Pilot

tlc4dna

The paperwork I have on this furnace says it's a 58SE but the illegible model number begins with a 394.

Sometimes the pilot will light and the furnace will operate properly. More often the pilot will not light and obviously the furnace will not heat. I have electrical knowledge in automobiles but not in HVAC. All my lne voltages (120) and transformer (28) voltages appear to be correct. I'm not too sure how to check for proper voltages at the pilot

What I am experiencing is the electric starter not clicking/sparking to start the pilot. I tapped the pilot a couple of times and it began working. When the pilot lights, the furnace seems to operate properly. It has a 3 wire pilot. For lack of knowledge of the sequence of events, I installed a new control board with no change inn the way it currently operates.

One other thing I notice is when the fan is turned to on at the T/stat, the fan will not run but it does run when the pilot has lit and furnace is heating up.

Thanks.
Don

biggles

that ignitor is looking for a ground make sure all is clean and no rust in or on the pilot assembly sand paper the area just opposite the ignitor rod check the ead to ground off the module should see voltage going out thru the orange wire to the rod... hitting it and it sparked and lit sounds like rust or loose grounding around the pilot assembly not different then the cars plugs with a solid ground

tlc4dna

Thanks. I will clean it up and recheck it after work today.

Doc Holliday

Pilot or spark ignition? Two entirely different things.

tlc4dna

I'm guessing spark ignition. It has a small black high voltage module and a silicone shielded wire running to the pilot. It sparks to light the pilot.

Is there a test for the spark/high voltage module? It has 28 volts to it.

Houston204

I don't see a Carrier 394. Could it be a Bryant?

Houston204

This is a Carrier 58SE manual with 3 wire ignition...

http://www.docs.hvacpartners.com/idc...t/58se-3si.pdf

tlc4dna

Ok, my bad. My paperwork says it is a 58SC not SE as I wrote earlier. It looks like the 58C not the Bryant. This model does not have a draft inducer motor on it. The only markings on the front are Day/Night

I removed the pilot and cleaned the mating surfaces as well as the spark surfaces. When I turn it on, I can hear the gas and I got one spark then it quit. I have voltage to the spark ignitor and I have continuity all the way to the electrode but no spark.

Is there a way to test the spark ignitor?

Doc Holliday

Change the ignitor first.