I replaced a White Rodgers thermostat with a Honeywell RTH221. When I removed the wires there was only a white, green, red and brown. I am assuming the brown is suppose to be the yellow wire. I hook up the wires and all that I am getting when I turn on the air conditioning is hot air and the heat does not turn on. Please help. Do I have the wires mixed up. There is only one wire left and it is black but was wrapped and not used. Please help. Thank you

Did you mark exactly what color went to what letter on the old thermostat like the directions that came in the new thermostat said to? If you did not you may have to track down the old wiring to where it goes into the furnace and find out what color is connected to what letter on the furnace.

I am afraid to guess because you can burn up your new thermostat if wired wrong or cause a problem with your HVAC equipment.

Here are the words right from the paperwork that came with your thermostat.


Identify and label each wire (with the corresponding letter on the
thermostat terminal) and remove it from the terminal.
NOTE 1: Ignore wire colors, use only letter designations to
identify wire types.
NOTE 2: If any wires are not attached to the terminals of your old
thermostat, you do not need to label them as they will not be
connected to your new thermostat.��

Here is the link to the instructions just in case they got lost or tossed out.


http://customer.honeywell.com/techlit/pdf/69-0000s/69-2060EFS.pdf

How do you change from centigrade to fahrenheit? No intstruction in the manual.

What will happen to the wires that are disconnected from the mercury