Very confused on wiring

[bryanjbenn]

I have a Q674L 1132 that I'm trying to replace with a Honeywell RTH7400. The original T-stat only has 5 wires.

W
G
R
O
Y

For the life of me I cannot figure out how that would translate over to the RTH7400. I've looked at the wireing layouts in the manual 100 times now and I am just not sure where the wires should go, and I certainly don't want to "guess".

Anyone able to shed any light on this *

[charity89]

I think you could choose "W" to try.

[Freon]

Look at page 22 and 23 of the Installation manual. That shows how to wire the thermostat for a heat pump. Based on the old wire connections I am assuming you have a heat pump.

[bryanjbenn]

Thanks...yes I do have a heat pump......but not sure where the "W" wire from the old tstat goes on the new one. There is no "W" spot.

[Freon]

Looking at the diagram on pg 23, the W goes to the AUX terminal on the thermostat. You will need to pay close attention to the setup instructions on page 17. Since the old thermostat was an O it appears the changeover valve setting will be 0.

[VeraKeisey]

The answer W is * So what's correct *