Sorry, if you’re tiring of reading these as I write about the experience of buying a Nest thermostat. Just move along if you’re not interested. :-)
Here’s the support e-mail I just sent Nest (via their online contact form) (Dec. 31, 2011, 9:15am):
We have three Nest thermostats in our house on a zoned system.
One of the thermostats has begun to often register a temperature (i.e, the current room temperature) that is more than several degrees (3-4) WARMER than the actual room temperature.
I have a digital non-contact thermometer that reads the surface temperature of whatever it is pointed at (not this model, but very similar in function: http://amzn.to/tbp0RH). Right now, for example, the wall temperature around the thermostat is about 66F. The temperature of the device reads 71F. Last night, it said 73F when the wall next to the thermostat was 64F. I have a second portable thermometer that confirms the air temperature very near the nest thermostat is around 66F.
We have a standard forced air heating system (no radiant).
The surface temperature of the nest reads 72F right now.
This wasn’t happening that we noticed when we first installed the unit and only started happening in the last week. I have not seen this problem with the other Nest thermostats in our home.
I’ll post updates here about their response to the issue. (The web site suggests it will be an hour or two before someone responds).
Has anyone else confirmed the Nest reported versus actual room temperature is accurate on their installed thermostats?
Update December 31, 2011
About six hours from my original request for support, I received a phone call from a Nest support engineer. (Note to Nest: you said the wait would be 1 to 2 hours …, manage expectations!)
We talked through the problem and he had me swap the thermostat from one floor to another. It’s relatively easy to do – but I did need to adjust the programming for both thermostats then. He promised to call me back Monday afternoon to see if things have improved (or changed at least). Of course, the issue should show up now in the basement (which is the thermostat I swapped the problem thermostat with).