Thank you so much for the responses so far. It is definitely not the thermostat. Just when the weather turned cold this year we lost power to our old thermostat and called our friend who works in HVAC to come take a look. He tripped the breaker which fixed the issue and that is how we knew to do that this time around. When researching causes my husband decided he wanted to Nest and we got it mostly for aesthetic purposes. So, definitely not the Nest or its set up causing the issue. Bare with me as I am new to all of this but will try my best to describe our system. I thought it was Carrier but was wrong. It is a 1988 Amana all-electric heat and cooling system. It was a tested factory model that the previous owner got from her father who worked at the plant and it was installed in September 2001. The breaker is in the crawl space and we have a 1700 square foot two story home. Are there any other details that might be helpful? My husband has a good friend who has worked in HVAC repair for several years. He is a friend but still not cheap! I think we may just call him back over to test what is pulling so much power that it is tripping the breaker, but thought I would check here first for some tips. Thank you everyone!

We are in the process of replacing a 1 year old...Yes,1 year old 4 ton ($12,400put in Aug.20,2011) air conditioner:TraneXL16i seer:16.5 furnace:TraneXV95 load calculation was done by 5 out of the 6 companies stating we needed a 4 ton unit. We just had a company come out and they said we are oversized by 1 ton and that was the reason for our whole problem?? We have what they call 'dirty sock' syndrome which started 2 weeks after it was installed!! 4 coil changes later still an issue. When we ran it in emergency heat over the winter,without a coil,no smell!!! With Tranes non responsiveness to all I would never get a Trane again!!!!!!!!!!!! Now I've read about all the problems with all units and am more confused then ever,but I do know that I will not get a heatpump again!!! Our original Lennox furnace(19yrsold)began getting stuck/freezing(not turning on) no smell issues whatsoever. Since we had just finished with our D.I.Y renovation of our home we decided to get a new unit,more energy efficient since it was the last thing that was needed to complete our home! I cannot believe how each and every contractor differs on their load calcs...you would think there would be some sort of protocol/procedure to do this accurately and come up with the same numbers?? More confused then ever~smile~Afraid to get that horrendous smell back in my house with another 'coil'...and Yes, we had one dipped and the procedure was done incorrectly , even the contractor said the chemical smell was making him ill...it was in the house for 1 hour and he had to take it out immediately after closing up the unit(took him an hour to install it). We had to air out the house mid winter and sit outside...stress to say the least....Any comments advice would be appreciated~smile~ I too live in W.N.C.

See there. Learn something everyday. This proprietary jargon is getting ahead of me. Good deal. You are getting one fine system that should give you years of good service as well as comfort and savings compared to that oversized system you have now. A little knowledge goes a long way. IMO Here is a link that might be useful: Evolution Connex Controller

Mike, yes. They have to give me the wired ODT sensor so I can lock out the heat pump. This was discussed between them and I several times before I signed on the dotted line and they had assured me this was possible. So as far as I am concerned they have to deliver on it even if it required ODT sensor. I just found another issue as I dig into this mess. I was trying to understand the fan behavior. In particular, from the sound it seemed the fan always ran at one speed. I was puzzled and digging into the thermostat menus, I confirmed this. The fan was either 100% or 0% speed. And it runs for additional 1 minute or so after the compressor shuts off (cooling fan delay). I found this odd - why did I buy a variable speed blower and why was I sold one. I mentioned this to the dealer and could get a satisfactory explanation. And then I checked the install guide - and it was there (see attached, in particular the graph and the table). There are four settings one can choose from. To really benefit from the variable speed the jumpers on the inside unit need to be configured in so called enhanced mode (option 4 in the table) where the fan starts at 50% speed and then to 80% for about 1 minute (fast cooling); the fan then stays on at 80% for 7.5 minutes (dehumidification); if necessary, ramps to 100% to get to the set point temperature and stays there as long as required, and ; ramps down to 50% and then 0% over three minutes to extract extra cooling efficiency. Well, this is not how my system has been configured. Mine is configured as option 2 in the table - 100% fan speed, followed by 1.5 minute delay - there is no variability of fan speed that can kick in. I have call in to my dealer...