Honeywell C7189R1004 Wireless Indoor Sensor, White

We underwent a complete overhaul: new Amana 18SEER, variable ECM air handler, and CTK04 communicating thermostat with builtin RedLink wireless capability. The thermostat location is technically "correct", away from windows/dead zones/etc., but the thermostat was unaware of the difference between our 1st and 2nd floors. Our communicating system adjusts the ECM blower speed according to demand and we were overcooling to generate greater demand to increase blower speeds for the 2nd floor.I bought four of these, put three of them upstairs and the final one in our southerly-facing living room with high ceiling. The displayed temperature changed and the thermostat increased the blower speed immediately -- awesome!Few things I figured out from piecing various documentation together (mostly from the T10 manual) for our ComfortNet/Bridge CTK04 system, generally applies to other Honeywell thermostats too:1. When multiple wireless thermostats are used then the temperature is a *weighted* average, the thermostat is 50%. Meaning that with our thermostat and four wireless sensors, the thermostat was 50% of the average, and each wireless thermostat made up 12.5% of the remaining 50%. I disabled the addition of our CTK thermostat to the temperature average for the cooling season. I will add it back to the average during winter to keep the upstairs from becoming overly warm.2. The thermostats follow a PID algorithm so do not expect an immediate change in the behavior of your system. It will learn how large and for how long temperature deviations exist and, overtime, will correct/anticipate runtime, blower speeds.3. Only one thermostat can be used for dehumidification should the capability exist on your system. Even though I disabled the CTK thermostat *temperature*, I have maintained it as the humidity sensor, and everything continues to work properly.

This listing is for only one sensor, even though the price is 50% more than any listing for a single sensor. The photo used is deceptive. Stay away.

I have a two story house and due to stratification a temperature differential exists between the floors. The thermostat does a great job of cycling the blower on a timed basis to help this, but that's not enough by itself to really do the job. Adding one of these in each of the upstairs bedrooms immediately raises the comfort level for both heating and cooling.Adding them to the system is a simple operation not unlike pairing a bluetooth thing to your phone. The thermostat gives you the ability to apply a broad range of names to the device to customize your setup. When the batteries get low you will receive notification on the thermostat.Don't get some wacky cheaply made unsupported system to control your home's HVAC system. Buy and install what the pros use, and that's Honeywell.

These make regulating the temperature in a 6 unit building a breeze. I would recommend these to anyone with multiple areas that need heating or cooling and want even temps throughout.

sensor looks and functions as described. price is comparable to what is available elsewhere.

The photo implies that this is a pack of 2 units but it wasn’t clear from the description. I only needed one but I'm glad to have a spare.It works well with my Honeywell ComfortNet Thermostat which had issues with accurately measuring humidity. The Thermostat also controls the AC to provide controlled dehumdification as well as cooling. With the erroneous readings the AC was overcooling in order to try to reach the humidity setpoint. This caused the AC to run for several hours needlessly. Now, with the remote wireless sensor, all is well with the operation of the AC and the right humidity level is achieved.

Received 1 sensor. I've used these indoor sensors before. I have multiple now. Was looking to add 2 more for new areas and only received one from this seller. Product is great. Seller is bad.

I purchased these in 2019. Work great - except one of the sensors stopped working about 6 months ago. For the price, I would expect these to last longer than 2.5 years.