I just bought a Hunter programmable model 44260 and trying to replace an old Honeywell for my heat and air system. The Hunter directions don't talk about a W1 & W2 terminals that the old one has.The Honeywell is wired like this - White wire on W1 ,blue onW2, green on the G, Red on Rc & Rh which are jumped , yellow on Y1 . Where do the W1 & W2 go? The new one has G, Rc , Rh, Y/O,W/B ,Y1. Any ideas?

Usually there is a 24 volt AC transformer in the furnace with the secondary winding connected to a red wire running to the thermostat and a blue wire, common, to the gas valve, A/C relay, and fan relay. From the thermostat there will be white wire to the gas valve, yellow to the A/C, and green to the fan. The thermostat is wired to switch the power from the red to the white, yellow, and green as needed with the blue completing the circuit. Most thermostats and furnaces have the contacts labeled R, B or C, W, Y, and G for the corresponding wire colors. It may be wired to have the A/C control wires return to the furnace and its controls and then a second wire goes to the A/C unit. Internal wiring may replace the green wire if the thermostat does not give you the option of fan only or continuous fan. Digital or programmable thermostats may need the blue wire connected to them.

Neither thermostat follows the above conventions completely. Go ahead with red again jumpered to RC and RH, and green to G. Study the directions for the new one, and identify the terminals the red wire is switched to for heat and air and the common connected to the other terminal of the transformer. Connect the white wire and yellow wire to them, likely W1 and Y/O. The W2 may be for the thermostat to control the firing rate for dual rate furnaces. If so, connect the same wire to it that is connected to W2 at the furnace. If the furnace doesn't have a W2, leave it disconnected at the thermostat. You should have a pair of wires running from the furnace to the A/C. One of them should be connected to the same terminal at the furnace as the yellow, and the other as the common from the transformer.

You may also need to look at the Websites for Honeywell and whoever made the furnace to figure out which wire were for what. Some questions I can answer. Some I hope to be able to help the asker figure out. This site makes it easy to post back and forth until we figure it out.


White wire on W1 ,blue on W2, green on the G, Red on Rc & Rh which are jumped , yellow on Y1 . Where do the W1 & W2 go? The new one has G, Rc , Rh, Y/O,W/B ,Y1.