No Fun with HVAC


Senior Member
Well, I received the 2nd Aprilaire 8870 and the Distro panel yesterday, learned a few lessons.

Lesson learned #767: Read the manual. Then read it again. Or else you might do what I did, and remove the HVAC wiring from one thermo, re-run to the distro panel, and then realize the panel is basically an RS-485 hub, and the HVAC wiring is *supposed* to go to the thermo that you just yanked it from.

Lesson Learned #768: If you're mucking with your HVAC, the installation/service/wiring manual for your furnace is a *good* thing to have.

Lesson Learned #769: If you're mucking with your HVAC, don't forget to turn off your furnace, or else you could accidentally short 2 wires and blow a $0.99 fuse and not realize it until 5 hours into the troubleshooting.

I haven't actually replaced the fuse yet, but I realized 30mins ago that the light in the furnace was flashing green 4x, yellow 2x. I read through the whole install/service manual, found the location with status codes, realized it said "Fuse open, short in the 24VAC wiring". Suddenly remembered that temporary spark I saw when I was re-running the HVAC wiring.

God I hope that electrical access panel is easy to access - it would SUCK to have to pay a $105 minimum repairman fee just to replace a fuse that the manual says is a "standard 3A automative fuse". Plus having no heat and waking up tomorrow to a dining room that's 56 degrees (again).
Time for another vacation?????

HVAC was the thing that has worried me the most when remodeling my house. I wasn't even worried when I replaced my breaker panel. :) :rolleyes: :rolleyes:
Do I thank you(Brian) or curse you for being so easy to order all this aprilaire stuff from :)

But, WooHoo! It works. Again, thank god I kept that furnace manual - it pointed me right to the fuse, and which screws to undo to get to it. Shockingly simple to do, VERY standard automotive fuse. Popped it in, and we got heat!

Still not working through CQC, not sure if I messed up the communication wiring, but at least the wife is off my back. Plus I need to learn how to use multiple thermo's.

All in, I feel quite good that even though I took 8 hours to do 2 hours of work due to a screwup on my part, I learned how to fix it and didn't just give up and call a repairman. (was very close I have to admit).