I just bought my first house and of course, started my new to-do list. One of the first projects was replacing the old thermostat with a programmable one.

I'm replacing a Honeywell t8034c1424 with a Honeywell RTH6300B. We have gas heat and central air.

The problem I'm having is with the wiring and making sure everything is hooked up properly.

There are 6 wires connected to 5 terminals the old thermostat:

G - Green wire
R -Red wire
W - White wire
Y - Yellow wire & Red wire
1 - Red wire

The Green, White, and Yellow are no problem, but I'm not sure what to do with the other red wires. My new thermostat has 6 terminals:

G
W
Not Used
Y
R (jumpered)
RC (jumpered)

My assumption is that I connect the R to R and leave the other two red wires (currently connected to 1 and Y) disconnected, but I'm not positive and wanted to get some recommendations for how to proceed.

Thanks for taking a look and let me know if you need any more information.

I actually just looked at my thermostat more closely and I was a bit mistaken earlier.

There are only 4 wires going in to my thermostat - RYGW - and there is an additional wire connecting the Y terminal to the 1 terminal. How should I handle that in terms of replacing the thermostat?

Check/note the terminal letters and color of connected thermostat wires at indoor unit. Post back with info.

1 may be internal. Meaning it's not another Red wire.

But R should stay jumpered to RC and call that R.

I think your on the right track.