I bought new Honeywell non programmable,letters are different.

Here are some options:

Honeywell Home Non-Programmable Thermostats: These thermostats are designed for simplicity and comfort control. They come in a range of models, from the classic circular dial to easy-to-use soft-touch buttons and backlit displays. You can easily set your preferred temperature with the touch of your hand. The Honeywell Home website has a range of non-programmable thermostats to choose from .

Honeywell Home Programmable Thermostats: These thermostats allow you to set different temperatures for different times of the day. This can help you save energy and money on your heating and cooling bills. The Honeywell Home website has a range of programmable thermostats to choose from.

Honeywell Home Digital Non-Programmable Thermostat RTH5160D1003/E: This thermostat is simple and intuitive to use. It has a backlit screen and basic button functions that make it easy to control the temperature. Once you set your desired temperature, the thermostat stores it in its memory, even during a power outage. Non-Programmable Thermostats ' Honeywell Home RTH5160D1003/E Non-Programmable Thermostat ' Honeywell Home Might as well look at the programmable ones on their site. Check their customer service if you have an additional question. The above mentioned should work with your setup.

Match the thermostat wires to the letters on the new thermostat terminals R Red Y yellow ETC.

Yes, it should work. Old thermo has 4 wires, follow instruction with new thermo.

I just installed a Honeywell 5.2 Day RTH2310B Programmable thermostat and I had to deal with the same situation: 2 wires, one white one black. After reading the edvice in one of the blog, the solution that worked for me was: BLACK ON Rc terminal and WHITE on W terminal. My furnace is running fine now. Hope it helps.

check wiring to furnace check wire hook ups on board match letters and colors sometimes installer use what ever wiring they chose on letters

W- White (heat)
Y- Yellow (condenser)
G- Green (Indoor fan)
C- Blue (Common 24v)
R- Red (24VAC)
O/B (Only needed if system is a heat pump)

I connected the blue wire to the R and the white wire to the W on the old thermostat and shoved the new Honeywell 5-1-1 Day programmable thermostat up the first guys *** that i ran into at Canadian Tire

Thanks for your help

check to see if the B terminal is on the new t-stat if connect to it , but this terminal refers to heat pumps and is normally use to energize the reversing valve on the outside unit and not used on ac units , but normally the tag O/B is the same terminal on therostats

did you mark which terminals you removed the wires from on the old stat? If not you will need to look on the furnace and see what letters they are connected to .. then connect to the same on the thermostat.