Bosch Large 5-Inch Full-Color Touch Screen Sleek Easy Setup Connected Control Smart Phone Wi-Fi Thermostat for 24V HVAC Systems with Bosch Connected Control App

I read quite a few reviews, and in most cases customers were replacing their existing non-smart thermostats with this wifi enabled smart BCC100 unit. Some reviews will scare you that you need a power source for this. Well yes, but do not worry... My house was built in 1993 yes I repeat 1993 and when I disconnected all the wires of my existing very old thermostat that had only 4 - Green / White / Red / Yellow wires I was a bit disappointed. But all these copper leads came out from a sheathed grey cable that also had two other unstripped (unexposed copper leads) - a blue and a black. BINGO... that was the key. Yes this new BCC100 will USE all 6 leads. So here is the connectivty: Red goes into a RH and RC already jumped (connected with a U on the BCC100 - you can connect into either RH or RC because they are already connected to each other!!!). Yellow goes in to the Y marked connector (Right side of the array) Blue (previously unused) goes into O/B marked connector (Left side of the array) Green goes into the G marked connector (Left side of the array) White goes into the W marked connector (Right side of the array) Red goes into the RC (RC and RH are already connected by a jumper clip) - right side of the array - RC is for Cool and RH is for Heat. What remains? The Black (previously unused lead). This goes into the top right array marked C. This is actually the POWER cable without which the unit will not work. Now one more feature: before you put this on the wall, you can setup the entie system. How? Look on the back of the unit. There is a connector similar to the one you use for yor android phone charger. If you have any such devices, take that lead and connect it and the unit will come on. You can perform the entire initial setup, schedule for heat and cool times and slots, calendar day-date, wifi, registration of your device etc, all the features without even connecting to the A/C-Heat unit. Now your unit is fully programmed and ready to be connected. Snap in to the wall plate after making connections as described above - JUST MAKE SURE THE AC / HEAT unit is unpowered. Once the unit snaps in the wall plate, power up the AC / Heat unit and you will see the BOSCH logo and you are all set. I had already downloaded the app and as soon as my unit got registered I was able to control it from my iphone. Extremely easy and very smart!!! Both units Home Upstairs and Home Downstairs registered and fully functional... You may get a few errors while registering the unit but just ignore them and retry (mine worked on the third try) because it will register without issues. I give 5 stars to this product!!!

First I'd like to acknowledge that these BCC100 t-stats got a lot of bad rep on Amazon. My personal experience is categorically different so much that I've upgraded both of my t-stats to BCC100 and have been super happy with my decision. I should also mention that I received no incentive from Bosch or Amazon and paid full price for both units purchased here on Amazon. I spent many hours researching (universal) t-stats online and landed on Bosch because I generally believe the company makes great products/tools/hardware and I didn't care so much about the 'smart' Wi-Fi features which seemed to be the source of the bulk of the negative reviews on Amazon, which were predominantely Wi-Fi connectivity complaints. We had a brand new Lennox system installed at our old house with the latest color-LED t-stat that I loved (no Wi-Fi tho). I paid $450 just for the t-stat alone (installation excl). When we moved to our new house, we inherited two old t-stats that had the standard on/auto fan function and required the user to manually switch between heat and AC, etc. I thought at $150 for a Bosch BCC100 t-stat, I'd give it a try. The reason I landed on BCC100 is a) I wanted something that's fairly universal/compatible with my HVAC system (more on that below), b) allows me to simultaneously set heating and cooling thresholds (e.g. heat up to 70F and cool down to 76F), c) allows me to run the system fan in 'CIRCULATION' mode, d) has a built-in humidistat and is able to control a humidifier accessory, e) has color LED display and is easy on the eye and f) is relatively affordable. a) My HVAC setup. I have a newer American Standard 2-stage furnace (i.e. Trane), a newer large-capacity 2-stage York AC unit, an Aprilaire 600 whole-house humidifier, an older 2-zone ECU that operates the entire system and two t-stats (one for each zone). I installed the BCC100's myself and have had the system running without any issues for 6+ months prior to posting this review. I'm extremely satisfied with my choice to go with Bosch and here's why. b) I'm able to set the low and high thresholds for AC and furnace at the same time and don't need flip a switch to go from heat to cooling or vice versa. The BC100 t-stat handles both call automatically. This is especially helpful in the Fall and Spring time here in the midwest when the temps drop below 50F at night and can easily reach above 80F during the day. BCC100 can kick in the furnace at night and the AC during the day with no action needed from me. c) We've had some major hot spots in our house (e.g. master bedroom) where the temp difference could be 3-5F degrees off compared to temp on t-stat, making it very uncomfortable. We'd faced a similar issue at our old house and found that, aside from upgrading insulation and seeking the air leaks around the house, the next best thing was to get a t-stat that has a fan 'circulation' mode. The circulation setting basically allows you to cycle the HVAC independent of furnace or AC calls. That made a huge difference in our comfort. We have fan circulation set to 20 mins ON, 30 OFF round the clock. That did the trick for us - no more hot spots! d) I'm able to set/control humidity from our BCC100 t-stat in conjunction with our whole-house humidifier accessory. You can use the H/DH and C terminals on BCC100 to trigger the humidifier. For our setup, I wanted to have BC100 turn on the humidifier whenever the fan is on vs. running the humidifier only when the furnace/heat setting is on. BCC100 interface allows you to select between 'steam' and 'evaporative' humidifier settings. I used for former to be able to run our humidifier regardless of the heating calls to the furnace. I don't have a dehumidifier installed at our house, but BCC100 also allows you to control a dehumidifier accessory. It uses the same D/HD terminal so you can only run one at a time, either a humidifier or dehumidifier. I should also mention that I used a simple relay switch to power our humidifier as I don't think that the BCC100 is able to power our Aprilaire 600 humidifier unit on its own. I used the signal from the D/HD terminal on the t-stat to energize the relay and close the power circuit from the furnace ECU to the Aprilaire unit. A couple months after the initial install I decided to try out the Wi-Fi connection. I was half-expecting to do a hard reset and then ultimately disable the Wi-Fi feature based on the negative reviews. To my surprise, I've had zero issues with my Wi-Fi setup on both BCC100 t-stats or the Bosch iOS app on my iPhone. Don't know if my Wi-Fi settings are more conducive to a flawless Wi-Fi integration with these units or if Bosch had fixed the previous software bugs with the current software release, but I'm thrilled that I'm able to use the iOS app and change my t-stat settings on the fly from anywhere on my iPhone. I honestly didn't expect the 'smart' Wi-Fi features to work at all so this was icing on the cake for me. Since I'm an iOS user I can't say if the app works as well on Android devices. I provided a few details about my setup below if you're looking to troubleshoot or replicate a stable setup at your house. Bosch iOS app version: 2.5.0 Bosch t-stat software version: 1.5.0 (the t-stat came preloaded with v.1.4.4 which I had upgraded to 1.5.0 once I had it connected to Wi-Fi) Wi-Fi connection: BCC100 will only connect on a 2.4 GHz Wi-Fi network, so that's something to be aware of. If you have dual-band Wi-Fi set up at home (5GHz and 2.4 GHz running simultaneously), you'll want to make sure you're using separate SSIDs for each band (e.g. XXX_5G and XXX_2G) and connect your BCC100 to the 2.4GHz SSID. The units are stable with 'WPA2-Personal' network encryption. I also have a very strong Wi-Fi signal to both BCC100 t-stat units which alone can make or break the entire experience. I don't know if this product is for everyone, but I personally love it. Hope this review helps you make an informed decision prior to purchasing this product. Cheers.