As the title suggests I am looking for advice on connecting a C wire or hooking up a Google Power Connector (I have it already) to my furnace.

I have a Lennox G803, it already has a humidifier attached as well as a Hoym air control thing (it's hard to read). I think I know what to do but I would really appreciate your input.

furnace schematics

main furnace part

overview picture

Power box note the transformer at the bottom for the hunidifier

Answer below from Jasen :)

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    Glad you got this working! Since you took the tour, you know that this place works a little differently than others. Instead of editing your original question to say "thanks", the appropriate thing to do is click the up arrow next to any and all answers that helped you, the click the check mark next to the answer that helped you the most. Also, it's preferred that you write up an answer of your own (self-answers are 100% acceptable) if you want to share the results of what you did. After all, if the answer is in the question, there's no point in reading the answers...
    – FreeMan
    Oct 1 '21 at 11:16
  • I tried to upvote the answer but I don't have enough karma to do so. I was also going to reply with an answer but there was encouragement from the site NOT to do that and instead comment on other people's answer. I commented on their answers but that won't let you post a photo so that's why I edited my original post to include the image. I tried FreeMan!! I tried!! Oct 1 '21 at 18:13
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    you should have enough points to vote now. Plus you'll get 2 more for clicking the check mark by the one that helped you the most!
    – FreeMan
    Oct 1 '21 at 18:29
  • Yep, I am going to re-edit, and change my update to an answer and remove it from the original. Thank you! Oct 1 '21 at 21:38

The red cable that exits to the right of the picture is worrying as it seems to bypass the flue safety device.

According the the diagram C is blue wire between the gas valve and the transformer

enter image description here

so these are your "R" "W" and "C" connections enter image description here

  • This worked perfectly. I am going to look into the Hoyme air intake thing and find its diagram. It was setup by the previous owners. I will add that the way they twisted in the wires was not great either. I've added my final pics up top! Thank you! Oct 1 '21 at 5:01

One of these two terminals on your control transformer is the C wire terminal. If you have a voltmeter, you can measure each terminal on the transformer against the R terminal. The C terminal will give you 24v, the other 0v (or close to zero). Of you don't have a voltmeter, you can simply use trial and error. You can't hurt the thermostat.

enter image description here

  • Yep that's what I thought too though I opted to go with what Jasen said above!! Thank you Oct 1 '21 at 5:01
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    Yeah, that makes sense since that's where the rest of the thermostat wiring resides. Guess I should have looked at the wiring diagram. I went for the easy win. 🤣
    – DrSparks
    Oct 2 '21 at 1:23
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    All good :) it was still helpful!! Oct 2 '21 at 23:57

Thank you to all who helped. /u/Jasen helped me sort it perfectly. Below is the end result

The key was the blue wire :)

End result

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