I have an older Honeywell electromechanical programmable thermostat which I want to replace with a Hunter Model 44360 electronic programmable thermostat. I can figure out the "w", "g", "r" and "y" wires but I have a blue wire on terminal "c" and a brown wire on another terminal marked"c" on the Honeywell unit. These wires are hooked up to the control board at the furnace with the blue wire hooked to terminal "c" and the brown wire to terminal "r".
Hunter instruction manual says to disregard any wires marked "c" on the old thermostat but also says to hook any wire marked "c" to terminal "y/o".? When I remove the brown and blue wire from the old thermostat the A/C compressor does not come on when in cooling position so they must be servicing some function??

Totally confused!!

Look at the sticky notes at the beginning of this board.

Were the brown and red wires both connected to R at the furnace? Have you jumpered RH &RC?

Were the brown and red wires both connected to R at the furnace? Have you jumpered RH &RC?


The brown wire is connected to the "c" terminal at the furnace and the blue wire is connected to the "r" terminal at the furnace. I also have a white wire and red wire going to the compressor. The white is connected to the"y" terminal at the furnace and the red wire is connected to the "c" terminal at the furnace. Yes I jumpered rc & rh.
Note. The is a high eff. Carrier furnace ( not a heat pump) When I separated the rc & rh and put the blue wire on rc and the brown to y at thermostat I blew the fuse on the circuit board an the blower motor ran continuously on the furnace until I replaced the fuse.

Hope this helps??

''the blue wire is connected to the "r" terminal at the furnace''
''and the brown wire to terminal "r"''

OK, we post stuff like that sometimes. Now fixing the problem.

For the compressor to run, power needs to flow from the R at the furnace to RC at the thermostat. When it calls for cooling, the power is switched to the G and Y terminals. Power then needs to flow to one side of the coil at the compressor. Usually that is accomplished by running a yellow wire to the Y terminal at the furnace, and then another wire out to the coil. Finally, the other terminal of the coil must be connected to the com at the furnace. So the red/white pair is correct.

I don't understand how the old system worked if the white wire was the only one connected to the Y at the furnace. No, matter, The new thermostat should work as I said to wire things.

''the blue wire is connected to the "r" terminal at the furnace''
''and the brown wire to terminal "r"''

OK, we post stuff like that sometimes. Now fixing the problem.

For the compressor to run, power needs to flow from the R at the furnace to RC at the thermostat. When it calls for cooling, the power is switched to the G and Y terminals. Power then needs to flow to one side of the coil at the compressor. Usually that is accomplished by running a yellow wire to the Y terminal at the furnace, and then another wire out to the coil. Finally, the other terminal of the coil must be connected to the com at the furnace. So the red/white pair is correct.

I don't understand how the old system worked if the white wire was the only one connected to the Y at the furnace. No, matter, The new thermostat should work as I said to wire things.


Sorry for the confusion.
Correction!! The brown wire is connected to the "c" terminal along with the red wire from the old thermostat and the "y" terminal at the furnace has a yellow wire coming from the old thermostat along with a green to "g" and a white to "h" and a red to "r" at the furnace control board. Should the rh & rc be separated and have the blue go to "rc" and the red go to"rh"?? Or leave the blue wire off and just leave the red with the jumper installed between the "rc" and "rh"??
Someone also told me the blue and /or brown is needed on the old thermostat to run the clock?? Is this right??

As long as you have power from the R at the furnace getting to both RH &RC, leave it the way it is. Some electronic thermostats need their common connected to the common at the furnace to have power including to the clock. Others manage without it.

Since you have a yellow wire, use it to connect the 2 Y terminals.

Argh! :eek: My husband installed a new Hunter 44360 5/2 programmable thermostat and it worked for the A/C however it is time to run the heater and it doesnt work. I dont know how it was set up before and he can't remember. :rolleyes::confused:Here is our current set up. Please help!! its getting rather cold.:(

g= green wire
rc = yellow wire
rh = blue wire (we also tried jumping rc and rh)
y/o = red wire
w/b = whire wire
y1 = nothing

please help!:eek:

Can`t understand why anyone would want to replace a honeywell tstat with a Hunter,, I know people are tired of hearing me say this,, but hunter tstats are not worth the trouble to install

My Hunter stat has been in service for many years. I could have easily replaced it and I would if it ever gave me any trouble but it hasn't. 5 years and still working fine.

You are lucky your Hunter has given you good service. Many years ago in the shop I collected a garbage can of old thermostats my servicemen collected off jobs where the thermostat was replaced for one reason or another. Hunter,Rite Temp and Lux made up most of them in the can. I always had very good luck with Honeywell and White Rodgers. To each his own.

Not really a preference. It was here when I bought the house and I just haven't had any reason to replace it.