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Problem: FYI Troubleshooting and cleaning a Bryant Carrier 3 wire pilot burner.

This customer was kind enough to share with me how he repaired his Bryant Carrier 3 Wire pilot burner. This customer had installed a new 3 wire pilot burner, then decided to clean the old 3 wire pilot burner to see if he could get it working. Sure enough he got it working again after 20 years of service! Below we have two YouTube videos made by Grayfurnaceman which show how to troubleshoot and the operation of a 3 wire pilot burner. Thanks Grayfurnaceman for making this informative video. We sell the Bryant Carrier 3 wire pilot assembly on the following page:  If you have any questions please feel free to email us at: or comment in the comments section below. We would love to have your business!

FYI – Without making any adjustments to the Gas Flow, I noticed on the new 3 wire pilot burner, that more of the pilot flame appeared to be striking the switch plate when the blower kicked in. So I re-installed it after performing the below maintenance and it too worked again. However, I figured 20 years of service was good enough and retired the old one with the new one.
a) From inside the chamber where the gas would enter the Pilot Burner and the brass fitting screws in, I blew out the Gas Nozzle and the little cone nipple that the compression fitting sits into. The hole on the cone looked a little stopped up.
b) Took Sand Paper to the strike plate and wet sanded it back to bare metal again.
It looked like the blower kicking in was stealing enough of the pilot flame away from the strike plate to cause it to cut in and out.
Thanks again for your attention and service.
Much appreciated.
Below we have two YouTube videos made by Grayfurnaceman which shows the operation and troubleshooting of a 3 wire pilot burner. Thanks Grayfurnaceman for making this informative video.

12 thoughts on “Problem: FYI Troubleshooting and cleaning a Bryant Carrier 3 wire pilot burner.

  1. My 3 wire pilot use to light but pilot would blow out, so I cleaned it out even the burners and then try to light it. But it just sparked but i could light it with lighter but burners would never kick on. Now pilot will not light even with lighter, the igniter just keeps clicking unless i connect the black wire above that opens gas i believe its number 3 of 5 on wires into gas valve. Help is it igniter gas vavle and 3 wire pilot?

    1. Hi Michael! I am sorry, but I have the hardest time troubleshooting these 3 wire pilots. I remember than I replaced the control board, spark ignitor and the 3 wire pilot and the problem ended up being the gas valve! Sorry that I do not know much about how to troubleshoot these. I would think if you are not getting 24 volts to the gas valve PV (pilot valve) then you either have a control board problem or a 3 wire pilot problem. If you are getting 24 volts to PV and the gas valve is not opening then you would have a gas valve problem. Here is a link to a pretty good Youtube video on how the three-wire pilot system works: I hope this helps you figure out the problem. We do sell a 3 wire pilot on the following page: Sorry, but it would be a guess as to whether this is the actual problem with your furnace or not. So sorry that I can not be much help. Steve

  2. I have this part it continues to click but never lights the pilot. seems that it is just not getting the gas for the pilot to ignite. does this part controle the flow of gas to the pilot or is that up at the valve assembly?

    1. Hi Jay! The 3-wire pilot burner does not control the gas going to the pilot. The gas valve controls the gas going to the 3 wire pilot burner. There should be a PV (pilot valve) and an MV (main valve) on your gas valve. PV should have 24 volts going to it to light the pilot when your thermostat calls for heat. You should be getting 24 volts between W and C (com) from your thermostat to your control board then 24 volts to the PV on your gas valve. I would suggest that you make sure that the limit on the furnace is closed. Steve

      1. I have this issue with a 30 year old Payne 396J furnace- the spark looks good, and most of the time it lights the pilot, but sometimes it just sparks for extended periods- like hours- without lighting. I know gas is flowing through the pilot because if I try lighting the pilot with a lighter or even just blow on it the pilot lights and everything works fine. The spark looks strong to me, but maybe it is weak and I need a new ignitor? Or should I just replace the entire assembly?

      2. Hi Ron! It sounds like you are not getting enough gas to light the pilot. I would suggest that you turn the gas off to your furnace and take 3 wire pilot out and blow it out with compressed air. Take the pilot gas tube off and make sure that the tiny orifice inside the 3 wire pilot is not stopped up with white gas dust. The orifice on the pilots are really small and can get partially stopped up. Clean the pilot up, reinstall the pilot and hope that fixes it. If it does not you might check and see if the gas valve has an adjustment on the PV (pilot valve). You might try to open this up to supply more gas to the pilot. We do sell a new LH680005 by Supco on the following page: I hope you can get the problem fixed soon! Steve

      3. Steve, thanks so much for your reply. I think you are correct. When I took apart the pilot line the orifice fell out, along with dust and debris. After cleaning the pilot flame is noticeably larger. Hopefully this will fix the issue.

      4. Thanks, Ron! I hope the cleaning fixes your problem! Best of luck! Steve

  3. Wiring diagram please
    White Green Yellow.
    Commonly closed / open

    Can’t buy $100 replacement part.
    repair with my own skills (electronics) might save me $$

    1. Hi David! I am sorry we do not have wiring diagrams for furnaces. Your furnace should have a wiring diagram attached to the furnace blower door or some where on the furnace body. Sorry that I can not help you out with a wiring diagram. Steve

  4. Thank you! I had worked out that the switch wasn’t working, but the problem was blockage in the pilot tube. Cleaned that out and now the pilot light branches properly and the flame sensor switches correctly.

    1. Great! Fantastic! Glad to hear that you fixed your furnace by cleaning out a blockage in the pilot tube! Yes, the flame sensing plate on the 3 wire pilot must have a good strong blue flame or it will not work. Thanks so very much for letting me and others know that a dirty pilot tube could cause the 3 wire pilot not to work. Hope you have a great Christmas and a Happy New Year! Steve

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