I have a Nordyne/Frigidaire heat pump. I don't know what model the heat pump is since the model number on the outside has faded away. The numbers listed on the thermostat are: 914832 and 3AAT86B59A1.
I have recently purchased a Honeywell TH8320 digital/programmable thermostat, and I have a couple of questions regarding the wiring of it. The current wiring of the Nordyne thermostat is as follows:
Y = yellow wire
G = green wire
R = red wire
O = orange wire
W2 = white wire
E = dark brownish almost black colored wire
C = blue wire
There is a black wire just hanging loose and not connected to anything.
I have three sets of questions regarding the installation of the Honeywell TH8320.
1) Should I just hook it up to match what is currently there?
2) Why is that black wire not connected to anything? Should I connect it somewhere on the TH8320 or just leave in unconnected like it is now?
3) The installation instructions state that the powering of the TH8320 can be made by either batteries or the 24Vac common wire. Can/should I use both? If I only use the 24Vac common wire and the electricity goes out, will I loose all my programming? I wouldn't want to program everything over and over again.
Thanks in advance for any and all help!