Hello everyone,

I have a problem with figuring out the wiring from a Trane XL80 2-stage furnace/ac unit to a Hunter Programmable Thermostat model 44155C. The existing thermostat is an old mercury based thermostat. It has the following terminals:

G1 - green wire
Y1 - yellow wire
W1 - white wire
W2 - blue wire
R - red wire

The new Hunter has the following terminals: G, RC, RH, Y/O, W/B, Y1. Since I don't have the manual for the furnace, I have problems with figuring out where each wire goes on the new thermostat. I've been able to figure out that the red wire goes into the RH terminal. I've tried many other combinations but the results have been the same: nothing.

Any help will be appreciated. Thank you.

Guristu

Wrong thermostat. BTW, do yourself a favor and buy another brand.

You need a 2 stage heat, 1 stage cool conventional thermostat.

And Rh is normally connected to Rc and connected to R.

Carefull: Some new stats require a common wire, C terminal, for power.

Wrong thermostat. BTW, do yourself a favor and buy another brand.

You need a 2 stage heat, 1 stage cool conventional thermostat.

and Rh is normally connected to Rc and connected to R.

Carefull: Some new stats require a common wire, C terminal, for power.

I was afraid of that. Anyway, I have no problem taking it back, but since I'm asking questions anyway, what would be the right thermostat for my system? I want a programmable one.

Thanks for the prompt response.

Guristu

1.Do you have any extra unused wires available?

2. Is it easy to fish another cable if you had to?

1.Do you have any extra unused wires available?

2. Is it easy to fish another cable if you had to?

1. there are only the 5 wires
2. I'd say it's pretty hard. I would rather not engage in fishing any other cables because I'm afraid the project may become too big for me.

I have done some research and I've found Honewell RTH6300B. From what I can tell it might fit my system. What do you think?

Thanks for your responses.

The RTH6300B is single stage. Won't do. This will RTH6220D: Buy Honeywell FocusPRO 6000 Programmable MultiStage Thermostat, Large Screen | Honeywell TH6220D1028 (http://www.iaqsource.com/product.php?p=honeywell_th6220d1028&product=100933)

Manuals are at this site too.

BTW: There is a way to "add-a-wire" without adding a physical wire, but it requires a high skills level.

I just fixed it. I went and I exchanged it for a Honeywell RTH7500 series. It's been working fine for a couple of hours now. Hope it keeps working.

Thanks for your input.

The RTH6300B is single stage. Won't do. This will RTH6220D: Buy Honeywell FocusPRO 6000 Programmable MultiStage Thermostat, Large Screen | Honeywell TH6220D1028 (http://www.iaqsource.com/product.php?p=honeywell_th6220d1028&product=100933)

Manuals are at this site too.

Sorry for piggy-backing here, but this just happens to be the one I was looking at and wanted to get, the 6220. The current A/C I have is 35 years old, but the furnace is 7 years old (Bryant 383KAV). You've brought up wiring issues -- do you think there would be any wiring issues with this, for the 2 stage heat?

The one difference is that I don't think running a new wire would be a big issue as it's not in some terrible area where it goes through to the basement. In fact, I'm going to be eventually running an outlet and phone jack on the other side of the doorway from where the tstat is and have no qualms about it.

It's a 2 stage heat conventional stat, so it should be fine.

The (C) terminal is optional. It would be recommended to run another cable while your in the wall. Having the (C) terminal means you don't have to have batteries to have heat and it opens up more tstat choices. (C) wasn't even needed or defined for mechanical stats. It's just the other side of the 24 VAC transformer. Between C and R you'll have 24 VAC all the time.

OK, thanks!

I just fixed it. I went and I exchanged it for a Honeywell RTH7500 series. It's been working fine for a couple of hours now. Hope it keeps working.

Thanks for your input.

I have same problem with rth6300b. How did you put cable in new one did you use blue cable at all please let me know.

Thank you

Ketan