Carrier Furnace Pilot light and Main Burner Flames out when main blower kicks in

furnacehvac

Carrier furnace runs for about 3 minutes. Hot air comes out from vent for a minute or so it then turns off and kicks back on after 1 minute or so.

I cannot find the model of the unit as the tag is so old. But here is a picture of the unit.
enter image description here

Image of inside
enter image description here

Image of electric pilot
enter image description here

Wiring Diagram
enter image description here

Opened up the furnace cover to observe and here is the sequence of the ignition:

  1. Thermostat calls for heat.
  2. Induction blower turns on. Pilot gas ignites. Last for 1 minute.
  3. Main burner ignites. Both Pilot and main burner stays on. Last for 2 minutes.
  4. Main blower turns on. Both Pilot light and Main burner turn off immediately.
  5. Main blower turns off.
  6. Repeat cycle from Step 2.

Video of when both pilot and main burner flames out.
https://imgur.com/a/TUTBb8p

Best Answer

Related Topic