I installed a NEST learning thermostat (www.nest.com) this weekend. No issues with the installation on my 2 stage heating 1 stage cooling, forced air HVAC system. I tested both heating and cooling and all worked fine. There are several problems which I have solved which may help other people who decide to install the NEST themselves:
1) The NEST will not behave as expected if the battery voltage is <3.7 volts. For example, I thought that the proximity sensors were not functioning, and that I had some obscure network connectivity issues upon first installing the NEST. The NEST would not dectect me as I approached it (approach detection enabled) and kept dropping my network connection. It turned out that ALL of these problems were related to the battery voltage being < 3.70 volts.
2) I could have waited several hours for the internal battery to charge up via the wiring, but instead, I opted to jump start the battery by using the mini-USB socket on the backside of the detachable unit. This solved the problems noted above, as well as allowing for an automatic software upgrade (which will not enable if the battery is below 3.70 volts).
3) After the software upgrade, I could indeed enter my Canadian Postal Code into the NEST, but the location still shows as “unknown”. The web and mobile apps, on the other hand, derive my correct geographic location from my postal code.
4) The NEST does not control humidity (although it does measure and use it). Therefore I opted to install a digital humidistat. This involved pulling an extra pair of wires from a 24vac supply for the humidistat, as well as pulling the outdoor sensor wire from outdoor sensor to thehumidistat. This was actually more work than installing the NEST itself, but essential for our dry Alberta climate.
For the next week or so, I will treat the Nest like an old fashioned dumb rotary thermostat while, behind the scenes, it learns my daily temperature preferences, when I am away, sleeping, etc. I’ll be using the mobile app to see what it is doing.