Amazon (Mostly) Smart Thermostat

If you're already in the Amazon ecosystem and looking for a smart thermostat, this isn't a bad place to start looking.

Amazon (Mostly) Smart Thermostat
I don't have a dirty mind, you do, this was a random picture! Giggity.

I've had a fairly simple four-period, seven-day thermostat since about 2008 which really does everything I need it to do. It sets the AC or Heat up to four times a day and can do individual seven days or group them into Weekday/Weekend. It does have a few limitations, however, such as there's no Auto mode, it's AC, Heat, or Off. And it has no auto circulate function, so if you need the fan to run to circulate air in the house you have to manually turn it on and remember to turn it off later. It did however have ways to monitor how many hours the fan was running to get a notion of usage, had a notification for when the filter has been in use for 500 hours, Vacation/Hold mode, etc.

But I really wanted something that I could have the fan circulate periodically automatically and be able to adjust the house temperature remotely on the very rare time I would want to do that. There were a few times away from the house I forgot to set it to "Vacation" mode, or times I knew the house would be hot and I was heading home from work early, etc. The Amazon Thermostat was at a reasonable price point to handle these sorts of things.

This post is mostly ramblings about thoughts, impressions, and some annoyances, of initial installation and usage. I will likely start looking for information resources and put actual useful info in here at some point.


Installing the thermostat was very easy. The wiring was easy, the push terminals made inserting wires into terminals easy, and everything was well-marked. Also, unlike my previous thermostat, there were no strange jumpers or questionable things when installing it.

While the installation went pretty easily, I initially found very little actual information on how to set up, use, configure, etc, from Amazon themselves. The listing for the thermostat just refers to "in the Alexa app", but googling or hunting on Amazon's support there is a help section. I've also found several YouTube videos on the subject which do fill in the gaps, but, strangely, Amazon doesn't offer more details on some of its features.

There is no way to set it up initially without a phone or tablet using the Alexa app. Unless you're already in the Amazon/Alexa ecosystem, you probably will not want this thermostat.

If you're unsure of HVAC wiring, have a professional install the thermostat. It's pretty easy and everything is pretty well laid out both the physical wiring terminal and the Alexa app help get things set up, but if you're unsure either take the time to understand the wiring or hire a professional. You should also make sure to power your entire HVAC system off while installing. I don't think you could cause any damage to your HVAC system, but better safe than sorry.

So far one of the biggest post-install concerns I have is that it can be rather slow to react in a dense neighborhood with a lot of 2.4GHz interference. Only supporting 2.4GHz is pretty limited and frankly, I was very surprised when I realized it didn't support 5GHz. I have a lot of 2.4GHz interference at my house and unfortunately have several 2.4GHz devices on top of that, so that network can get rather congested and has high latency at times. The Alexa app seems to set the thermostat in real-time, so if I'm having high latency on 2.4GHz, that also means I'm going to see poor latency in the Alexa app waiting for settings to load, change, and save. I was attempting to change my schedule in the Alexa app at one point and it just would not load at all. A while later it seemed fine. After you set up the thermostat you probably don't tinker with it much, but initially, this was a little frustrating.

I also realized that I meant to set my AC temp to a different default temperature, so I set it in the Alexa app and expected the schedule to automatically reflect that change but it did not. I had to edit the schedule (not changing anything!) and when I saved the 'changed' schedule, it also reflected the updated default Heat/Cool temps. So if you decide you want your AC to be 77 instead of 76 you can't just change it in one place; you have to modify your whole schedule to make that happen. Almost feels more like a bug than a feature.

Modes on Thermostat

There is a confusing array of nodes on the thermostat itself due to the fact it only has a single Mode button to select. Here they are in order but keep in mind it starts in the mode you're currently in. Note that there is an option for "Fan" in almost every mode, but this is running the fan continuously. The only way to set the fan to circulate periodically is in the Alexa app. If you set the Fan to circulate in the Alexa app, the Fan icon on the thermostat will blink. The circulate mode seems to run for about 10 minutes and is off for 20 minutes. I originally would have assumed that if the heat or AC has run recently it will not run again but that unfortunately is not true; I've heard the AC turn off and the blower turn off, then a few minutes later the blower turned back on.

  • Off
    • Everything is off
  • Off + Fan On
    • Heat/Cool is off, but the fan is on continuously
  • Cool (Auto)
    • This is how you set the Cool temp in Auto mode
  • Heat (Auto)
    • This is how you set the Warm temp in Auto mode
  • Cool + Fan (Auto)
    • Same as above, but also runs the fan continuously
  • Heat + Fan (Auto)
    • Same as above, but also runs the fan continuously
  • Cool
    • Cool-only mode, will not switch to Heat automatically
  • Cool + Fan on
    • Same, but run the fan continuously
  • Heat
    • Heat-only mode, will not switch to Cool automatically
  • Heat + Fan on
    • Same, but run the fan continuously

Various Positives

Its appearance is pleasing and the device itself is rather small. If the back plate were smaller it'd look even smaller than it does. The base plate is really large, probably 2/3 larger than the thermostat itself. This is perhaps handy to hide installations of other previous thermostats but seems oversized to me.

Automatic circulation mode is very nice to have, although it would be handy if they told you how often it came on and for how long.

No Alexa devices are required to use the thermostat. Once you set the device up with the Alexa app you could, in theory, only use the device itself with no Alexa devices and without using the Alexa app, but it isn't particularly user-friendly. Also, note that the thermostat itself is not an Alexa and has no microphone or speaker.

Setting for enforcing a minimum Cool and maximum Heat temp to avoid someone in the house setting the thermostat manually to some silly temperature is good. I've threatened to put a box over my thermostat a few times in the past and this would fix those sorts of situations.

The thermostat shows the current humidity in the Alexa app but does not show it anywhere else nor do anything with this information that I am aware of. It would be nice if you could set the thermostat to turn on the Cooling if the humidity gets above a set point for example.

Big Issue; Short-cycling the system

It took me a few weeks to figure out what was going on and with some googling discovered that the thermostat is short-cycling the system because the "swing" is too small. Most thermostats have a swing of 2 degrees, which means if it's set to 74F it'll cool until it's below 73F then let it heat back until it exceeds 76F before it turns back on. But this allows the system to run a little longer than it has to but also means it's not cycling on and off constantly.

Unfortunately, this thermostat seems to have a very short swing and is constantly turning on and off. With the AC set to 74F, when it turns off and the house starts warming up the instant it hits 75F, the AC turns back on. Same with the heat, if it's set to 68F the instant it hits 67F, it turns on. I'm finding the AC turning on and off every 10 or 15 minutes and it's relatively cool outside still; this summer when it's really hot and the house warms up fast I imagine it will only get worse.

This will lead to increased wear and tear on the central heating/cooling system and possibly make it have a shorter life.

Amazon is aware of the issue. And they just keep telling folks how to "adjust the temperature" basically.

Manually Created Routine for Short-Cycle Work-Around

On the Amazon support forums, a user suggested his work-around for the short-cycling issue he created routines to manually create a schedule for this thermometer. Initially, I did not want to do this as it sounds like it'd be really fiddly and annoying to modify, however, I've given it a try and it seems to work... with a bug or two. I created a separate article, Fixing Amazon's Thermostat on it because it's a fairly long write-up.

Minor Annoyances

I've noticed that the "Pre-Warm/Cool" setting seems to heat/cool well ahead of when it needs to. For example, overnight I have the Heat set to 60F in the winter. Overnight, the house had dropped to 66F and the schedule is set so that at 8 am it sets the heat to 68. Looking at data from a thermostat I have in the house I can tell that it started heating at about 7:15 and was 68 by about 7:30, well earlier than the 8 am setting. Another example; the house was at 65F at 5:55 am when the thermostat is set to turn up to 68F at 6:30. The heat turned on and was at 68F within 5 minutes. I would expect that the thermostat would heat an appropriate amount before the set time with this setting so that it was at a temperature at the set time but not 30+ minutes ahead of time. I will keep an eye on this, 2 degrees is a pretty small delta here so as we get into the summer season I'll see how it does with adjusting the house temperature and how far ahead that happens. The thermostat may learn over time to figure out how long it takes to heat/cool the house.

I'm pretty surprised by how weak the filter notification functionality seems to be. It appears to only track how long the filter has been installed, but not hours of actual use. Filters should be changed after N hours of air passing through them, including fan-only/circulation.

I am missing my old thermostat's one-button "Home Today" feature which skips to the next period so the house is heated/cooled the way you want it to be while you're there. Sure, I could probably tell Alexa I am home, but if I want to do it quietly, it's a few taps of the Home button to get to Heat, then a bunch of taps to get it up to 68F from the overnight default of 60F. And AC is set to 78, so if the house gets warm during the day, I'll have forgotten to also set the AC temp down lower. A "Home Today" button on the thermostat would be nice here; one tap to go to your normal "Home" temp settings. They could also add a "Home Today" kind of button in the Alexa app, but so far I'm not seeing a way to do that except manually adjusting the Heat and Cool temps.

It feels like the device has an overly simple physical input method. It has lots it can do in software, but the device itself only has a Mode, Up, and Down button. I'm sure this keeps costs down but could be more intuitive to use, like a Nest that has a dial-like user interface. Or just offer a touch-screen interface with buttons/icons to tap. Tap between Heat and AC temps, etc, without flipping through modes.

My wife misses the clock our old thermostat had on it, and I have also realized that I too often looked at the clock while walking past it. It would be handy to have a small clock on the display. Also, it'd be nice if there were a way for it to show more details while in idle mode, such as if it's currently heating, cooling, or if the fan is running, but when it's idle it only shows the current ambient temperature.

Energy Dashboard

The energy dashboard could be pretty handy to have, however, it doesn't seem to really give you any really useful information. It hasn't registered any energy usage for the last three days that the AC is running. It registers some time, but no Energy usage. Maybe it only estimates heating energy, which really doesn't make any sense a gas furnace for heat uses significantly less power than the AC for cooling.

And it'd be nice if it would tell me how much time the system ran in total, not just display the average hourly time. Also, there's not a lot of granularity in the setup, I can't input how many watts my fan uses, and I can't input how many watts my AC condenser uses, it's just estimates based on your house size, general setup, and a wide range of bill costs. The energy dashboard also seems to not attempt to track Fan on/circulation power usage. The heat was on one morning until about noon but it was warm enough the rest of the day to need no heat, but I do have Fan Circulate enabled. It showed no power usage in the Dashboard for the remainder of the day.

Also, installing the thermostat made all my smart outlets and bulbs disappear from the Energy Dashboard, or at least I am pretty sure they were there before. Yes, the power consumption of a central heat/AC unit is significantly higher than all of them but I'd still like to track how much my lamps are using.

Alexa Interaction

Alexa's voice commands and Routines are very, very limited when controlling the thermostat. If you say "Alexa, set cooling to 74 degrees", Alexa will set the temperature range from 72 to 76 degrees. Same with heating, a two-degree range. There's no way I can tell to make it set the heating point to 68 and the cooling point to 74. I've tried chaining two commands together and it only set the range two times in a row. During the Summer or Winter, this may not be an issue, but in the Spring and Fall when you may need AC one day and Heat the next, it doesn't work, and it's amazing they support auto heat and cool points but Alexa can't set them.


I wish it had a minimal API to access the current temperature and maybe some other settings you could query or even set for things like Home Assistant.

It would be nice to optionally get a notification from the Alexa app when the thermostat has been adjusted.


When I was looking for a thermostat that could auto-circulate periodically and still have multiple periods per day for heating/cooling I was not seeing anything much below $45. With the Amazon thermostat at $65 (when you catch it on sale), it was pretty much a no-brainer to get it. Yes, it has a lot of cost reduction in the display, such as I'm pretty sure it's a very basic colored lens display like a lot of cheap weather stations do and its inputs are limited therefore changing settings is a bit confusing. But as long as Amazon supports the thermostat for years to come and you're already in or will join the Amazon ecosystem, I don't see how you could go too wrong getting one.

Would I buy this again? No. The short cycling of the system makes me want to replace it because I am concerned it is putting extra wear and tear on my system. I certainly would not buy it again. Amazon could trivially fix this issue but I've seen posts about it several times in their support forums and they always just post how to set up your temperatures and ignore the actual problem.


I'm going to list a few references on the net I've found that have helpful resources or can fill in gaps that Amazon themselves don't seem to (directly) cover.

Do note that the Amazon app and/or the thermostat itself may change over time, so references here might eventually refer to older application versions, screens may change over time, etc.