I had a Carrier builders non prog thermostat which controls my AC-heat (and air exchange) - The wires hooked in it were white in W, Yellow in Y, Green in G, Red in R and black in C. The orange and blue wires were not used.
I purchased a Honeywell RTH4300B. I switch off the main breaker and started to hook it up. The Yellow in Y, the White in W, the Green in G, the Red in R. but now , there is no C. There are only O, B and RC. After puttting the power back on, and the 2 AA batteries ( I waited a good 5 minutes between each of the 3 black wire hook ups) , I tried to plug the black wire in all 3 one after the other, but nothing happens... no heat, no cool, no fan.. I am wondering if this thermostat is OK or the right one.
In some cased it tells me not to hook up the black wire (which used to be on C on my old thermostat.

Perhaps I need to reset my electric Carrier furnace??

Help

Is your Carrier a electric furnace or a heat pump, this stat won't work on heat pumps.

Thanks for your help. I have a carrier electric furnace. It is not a heat pump. I also have a Carrier AC and a Venmar air exchanger.