I've having a problem with my rheem model rgdg-10nbrjr
The air conditioning works, turning it on at night it blows cold air and the house indeed gets cold.
However the furnace unit itself constantly turns on in this sequence with the thermostat off (I've even removed it and it still happens): 1. Blower turns on 2. Inducer motor starts running for a number of seconds then I hear a click and it spins down, a few seconds later starts to spin again, repeat. You can hear it here in the video around 20 seconds here:
Sometimes it runs for a few minutes, then shuts off only to start the cycle again. At times the inducer motor will cycle every second or two.
I've tested the fan limit switch and it shows closed, I have continuity across it.
It's about 73 degrees in our house (ambient), not hot.
Any thoughts? If this happens to be the control board, any tips on finding the right one? I'm having a bit of difficulty looking it up. It seems there are generic boards, unsure if they line up, any issues using them (like flame sensors as this is an old unit), etc.