Have Honeywell Pro 3000 TH3210D thermostat. It has 7 wires hooked up to a 2 heat/1 cool system. E Aux Y G O R C. Where does the E wire go on the Nest?Does the Aux wire go on W1 or W2?

  • Can you post photos of the wiring at both ends? – ThreePhaseEel Nov 12 '17 at 16:18
  • Did you ever get this resolved? If so, please give a check-mark to the answer or write up your own answer explaining what you did to get it fixed and give yourself a check mark. That will help others with this kind of problem know that this has a resolution and is a good place to look for their answer. – FreeMan Aug 5 '20 at 12:42

The 'E' typically goes to what is called 'emergency heat' which is often the same as and is connected with the 'AUX' (auxiliary heat) used with a heat pump system. In our area we normally designate this our second stage of heating and it doubles as the primary if and when you need service for an extended period on the outdoor unit. These type of thermostats are connected in a lot of different ways. I would need to see and understand your entire system and how it is designed to work. And I need to know how you want to use energy saving measures. Additionally, I need to know your comfort level demands.

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