I just had a new heating system installed ( maytag Furnace #PGC2TC080D35 and Air Source Heat pump #PSH4BE030K ) and kept my electric plenum heater ( Electromate EM-LV20218 ) in place. I'm stuck trying to figure out how to make it work with the Honeywell Visionpro IAQ #TH9421C1004 with the EIM. I can figure out the basics, with the furnace, but am getting confused when I add the HP and then get completely lost when it comes to the plenum htr. Here's what I have so far: Furnace ----- EIM ------- - HP -------------- W/OB -------- O W1 -------- W2/Aux -------- W2 W2 --------- W3/Aux2 ------- E Y/Y2 ---------- Y --------- Y Y2 G ---------- G C --------------- C --------------- C R --------------- R --------------- R Outdoor Thermostat will be connected to EIM Out 1/2 Does this look like it will allow the heatpump to work with the Furnace properly? The Plenum heater previously controlled the last system using a Honeywell thermostat. I'm wondering if I have too many things to run with this IAQ. The last part is that my HP/AC is powered by Dual Fuel electrical and needs to be interruptable using a LCM supplied by my local power company. It has two wires ( red / white ). Can I tie it in on the C connection between the EIM and the HP? I know it's a lot to ask with my first post, and I hope you can help me out.

Hi all. My downstairs thermostat only runs heat. The old thermostat had W1 and RH, which work fairly well with my new nest 2.0. However, I occasionally run into issues with the furnace turning on/off every few minutes for no reason, and I'm told that a common wire should fix the problem. There was an extra wire that I found 'hidden' in the wall behind the thermostat, which connects to nothing in the basement. My furnace does have a 'common' terminal (see upper-right in photo below). Do I simply connect the extra wire in the basement to 'common' on the furnace, and then plug the other end into 'C' on my nest? Thanks so much! [IMG]http://i.imgur.com/tuMJH.jpg[/IMG]