Instruction: Evaluate the answerability of a question by analyzing the related document, outputting yes if the document contains information addressing the question, and no otherwise.

Input:
Question: Since the system auto-connects after a power outage, what is the point of the return air sensor? I don't know how or whether to install it.
Document: Be sure to read and understand your existing setup and map out your new connections appropriately before you get started (I also take 'before' pictures with my iPhone to keep track of where everything was before changing things). We did not install the return air sensor since our original installation didn't have that feature.
Works exactly as advertised. Easy to install once I realized which wire was the one that supplied power. If access to your thermostat wire is limited make sure it is a 4 wire cable, you will need all 4 wires to install correctly. As others have noted the return air sensor is not necessary and I did not install it either.
I'm no electrician or even much of a handyman, but simple logic makes this an easy install. Just put the wire in the C terminal on your current thermostat to C terminal on this unit. W to W, and so on.3. The return air sensor is not necessary. If you don't know what this is, don't worry.4. The large grey piece with the red on the bottom is what mounts to the wall where your existing thermostat/wires are.
Just installed the unit - installs easily out of the box. I spent about 15 minutes to mount the base on my wall and connect all the wires. I didn't install the return air sensor - it's optional. I also din't mount the thermostat - I prefer it to be mobile. I can now put it in my bedroom for more accurate temperature control, or bring it downstairs if we're all there. Very flexible.
I purchased this model because the existing thermostat in our home is in a location that seldom reflects the temperature and the rest of the home was either too hot or too cold no matter how we tried to balance the.vents.The kit has three parts - a large (ugly) control unit, the thermostat proper and a return air sensor box.
It should be noted that the thermostat wire I had in my wall had all the wires needed to hook up everything in this kit - including the return air sensor wiring. That may not be the case for others.When I pulled the EIM out of the box I realized that mounting it in the hallway wasn't an option. This thing is pretty big - around 8 inches square and about an inch deep. Being grey, red & large, it didn't exactly blend into the wall.
Great product kit. The return air sensor is NOT as pictured on box or inside the installation. There is a discharge/return air sensor in the package, just a different one.
Before I purchased, I researched and read the various review comments relating to individuals needing to hirer a professional to install, which I ended doing the same. I was warned by a handy man (who could not install) that "if you don't know what you doing, you could short out your entire air conditioning unit". So, I hired a heat and air conditioning tech and for $100 he was able to instal the unit within an hour.
I saw the reviews about how the thermostat can lose connection in the case of a power outage. So far that hasn't happened at our house. I gotta say that this thermostat has saved us a fair amount of grumpiness and frustration. Now it's always the perfect temperature where ever we're sitting.My husband did have to install an additional wire between the furnace and the larger control unit, but aside from that, this was very easy for him to install.
I didn't even know wireless thermostats existed until I had to start looking for options when my current wired thermostat system malfunctioned and I had to possibly pay for an electrician to come in and snake the walls with a new thermostat to furnace wire. At $200, this was a much better choice. The base unit is light and can hang anywhere near the furnace.
Answer: yes