Replace DICO Thermostat with a HoneyWell RTH230B

[number1.email]

Hello, I'm trying to replace my old DICO Manual Thermostat with a new Programmable HoneyWell RTH230B. There doesn't seem to be a model, part, or serial number on the old thermostat, so I can't locate any information on it via the Web (If you remove the fact place the following numbers are stamped on the wall plate: 8639 E6 4). At any rate, there are 4 wires going into the unit from the wall...they are red, blue, green and white. Can anyone help me figure out which wire goes to what? Thanks in advance...

[Travis Jordan]

Note that color coding assumes that the installer followed the standards. Many don't. If you aren't sure then check the thermostat wiring where it connects to the air handler / furnace to be sure.

[SQLit]

How do you know if the Honeywell is even correct for the application?

4 wires could mean a plethora of different systems. Best to trace the wires down and see what they do before you go much farther.

[Travis Jordan]

As long as it isn't a HP, he's probably OK with that model.

[hvactech2]

I need a lot more info than you give here is this Heat/Cool? I need model and serial of all units.

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