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hiper97
Sep 30, 2009, 06:05 PM
I am replacing an old emerson electric thermostat with mercury for a programmable Honeywell thermostat. I have only a furnace, no A/C. When I took the cover off the old thermostat I have 4 wires, 2 black and 2 white, which were connected on two connectors, black at the top on the right side and white on the bottom right side, each colour attached to same screw.

My problem now is what wire(s) go where?? W Y or G, I am assuming the W is for white, but does this mean both white wires get attached to the thermostat... :confused:

Isn't this supposed to be basic?

Thanks for your help!:D

NorthernHeat
Sep 30, 2009, 06:18 PM
Connect white to white and black to red. If there is a Rh and a Rc connect it to Rh.
And I assume you wad White. White to one termainal and Black. Black to the other terminal in the old stat.

letmetellu
Sep 30, 2009, 06:22 PM
On your new thermostat do you have some small switches that give you an option
Of "Heat - Off - AC" and another switch that says Fan "On - Auto). If so you have a thermostat that is for heating and airconditioning but that is not a real problem you can make it work on just a furnace.

I don't know why you have two black wires and two white wires. But here is what you do. Connect the two black wires to the terminal on the thermostat that is marked Rh. Connect the two white wires to the terminal marked W.

This will turn you furnace on and off as the thermostat reaches the proper tempature.

The one switch that says heat or cool should be in the heat position the other switch will not matter at all.

If you need more help let me know.

hiper97
Sep 30, 2009, 07:05 PM
Just one final thing, there is a jumper wire between the Rh & Rc, so I believe then that I would take that out?

Thanks for the help!!

letmetellu
Sep 30, 2009, 07:12 PM
It does not mater about the jumper, it is there for a.C. System that uses two transformers and you do not have A.C.

hiper97
Sep 30, 2009, 07:44 PM
I think I have it... thanks for your assistance!