Ok i have a ruud heat pump, not sure if it's multi stage or not. I recently replaced the old radial honeywell T87F 2873 with a new honeywell RTH7000. The old thermostat has 6 terminals of which 5 were used, though the wire is only 4 conductor. RED, GREEN, BLUE, and WHITE. On the old thermostat the terminals were labled B,G,Y,W,R,O they were connected as follows. BLUE = B, GREEN = G, RED = R, WHITE = W and was bridged to Y. After playing with the new thermostat which has a 7 or 8 different system setting i connected as follows. R/RC= RED, O/B = BLUE, G = GREEN, AUX = WHITE bridged to Y (the book said to bridge this to Y1 which didn't work, so i bridged it to Y, which did work) when system is set to 1 (electric heating / cooling) the system AC works fine, but heat doesn't work When system is set to 2 (heat pump) the system works except for one odd thing. When you turn on cool it turns on heat, and vica versa. It shouldbe noted that switching system to any of the multi stage settings for heat pumps doesn't work at all, and when when bridging Y1 to AUX instead of Y while setting the system to 2 (heat pump) nothing works either. Perhaps i have a wire switched or somthing, i never thought wiring a thermostat would be such a pain, please help. Thanks ~shane

Hello, I would very much appreaciate any help on hunting down a description of what each wire on a GE WeatherTron BAY41X213 (model # 3AAT83D1D5) thermostat does. The reason I'm looking for this info is that I'm trying to replace it with a Honeywell RTH7400D (which should support both single and multi-stage heat pumps). However, I can't get all the wires to match up. When I called the Honeywell folk, they didn't have my thermostat on record and can't help unless I can tell them the function of each of the old wires. The old WeatherTron: O R T M G Y X2 B U (and W hardwired together) F (exists on the thermostat, but not connected to any wires) The one that seemed to stump the Honeywell guy was the M. I tried checking out the GE website, but couldn't find anything useful. If anyone knows of another way I can find this information, I would appreciate it. Thanks, Andrew P.S. I've just noticed that the new Thermostat is rated for 24 V systems, while the old WeatherTron seemed to support 30 V. Will this force me to find another thermostat?