My house is a 5 zone HVAC system. I purchased the original nest for my bedroom, and it worked well. I purchased 4 new ones of the new version (which I hate) since the older one is not available. about a week later, I had a problem with my a/c in the house due to the fact that the new thermostats require further installation of an electrical wire to provide more power to the rechargeable batteries. After spending over $1,200.00 in Nests products now I have to spend more money to have a technician install this power supply at an additional cost. I have had two professional HVAC companies out to install power to the nest and still have issues where my a/c is not working because of the thermostats. We are in a heatwave, and I am beyond myself that I can't get anyone to figure these complicated thermostats and I am stuck with no A/C. My house is only year-old custom built so these units are all brand new. Nothing is wrong with the equipment. I would love a refund on these thermostats, and I will go back to Honeywell thermostats that work and are literally bulletproof or send me the original version of the Nest that actually works. Beyond unhappy and will tell everyone about how horrible this product (and experience) has been.