Honeywell Home RCHTSENSOR-1PK, Smart Room Sensor works with T9/T10 WIFI Smart Thermostats

My T9 thermostat came with one sensor that I placed in the master bedroom. Since I spend a lot of time in my home office, I wanted a second sensor to add to the thermostat. It paired easily and now maintains the temperature in the occupied room and not just the main room and master bedroom. Works well.

So far these items are working as predicted.

The thermostat alone is worth the money. Highly programmable and for the past month has performed very well in the Florida heatwave.I am enamored with the room sensors. I have a large house with a bonus room above the garage, but only a 1 zone unit. (What were builders thinking?).Anyway, that room was getting to 88 degrees and above during the daytime which made it unbearable to be up there. In addition there is a West facing bath, hallway and bedroom that also saw temperatures above 85 in the afternoon. I used a sensor in each space. The A/C ran continually for a couple of days, but the whole house is now staying around the set temperature of 78. And does not come on most nights. The other thing I did was set the thermostat to 'circulate' so that the fan runs when the A/C runs AND periodically at intervals (not sure what intervals) so that there is a nice consistent temperature in every room. Even the ones with 12 foot ceiling which used to feel significantly cooler than the rest of the house.Finally, the Resideo app to control the thermostat could use some work, but nothing for me to really complain about at this time.

I have two ducted Mitsubishi inverter heat pump systems using MHK2 sometimes also known as MRCH2 thermostats. The upstairs system had the thermostat located in a poor location especially in winter. It resulted in the two bedrooms upstairs being about five degrees colder than the set point. I didn't want to put the thermostat intself in a bedroom but I needed to have a temperature sensor in one of them to read the temperature there. I temporarily moved the MHK2 to one of the bedrooms (it is wireless so easy enough to do) and confirmed that reading the temp in one of the bedrooms would get me to where I wanted to be.A few Google searches found some reddit threads that confirmed this sensor would work with the MHK2 even though it isn't listed as compatible. I ordered one from Amazon and can confirm it worked great. Download the MHK2 instructions on pairing this and setting it up (it is wireless). You basically need to sync it with the Redlink controller on your unit (which thankfully does NOT unsync the MHK2). Once synced you need to got into the MHK2 setup menu and select using this sensor (you can either use this remote sensor only--what I am doing, or an average of this sensor and the MHK2 sensor).

This device is actually great when it works. I have two of them connected to my T9 thermostat and they work as intended. The problem is the fact that the manufacturer made changes to the thermostat and/or the sensor since I originally purchased the T9 in 2021, and the extra sensor in 2023.There is no way of telling which version you are buying by looking at the product description and the packaging. I called their customer service when I was not able to establish a connection. The rep wanted to start a video call so she could see the labeling on both products. However, their video call system did not work on my phone so I was asked to email pictures of both as well as proof of purchase. I did not understand why they would need the proof of purchase just to tell me if the two devices were compatible. She finally agreed to check compatibility first and then ask for proof of purchase, if needed. It turns out they need it for a possible replacement. I still don't get it as I bought this on Amazon and not from the manufacturer directly.I emailed the pictures, was asked for another picture, i.e., the label inside the battery compartment of the sensor which I sent.By the way, customer service answered the phone right away so I give them credit for that. The rep needs to improve her listening skills and use her judgement instead of just following the script she is given. For instance, I told her that the reset procedure listed on the company's website (press the connect button for 15 seconds and wait for the orange light) did not work on my device. She could have easily asked me for the number printed after the model number instead of asking for pictures. That would have solved the problem.After that I did some research online and realized that this is a known issue: Series 1 of the thermostat is not compatible with series 2 of the sensor so I returned the product. As always Amazon was great with the return request.In summary, do not buy this if you bought the T9 couple years ago and would like to add another sensor, like I did. Resideo website has the old version available for purchase so I may buy one.In my opinion, it is a poor manufacturing practice to make changes which are not backwards compatible.

I wasn’t expecting a dramatic difference, but this little sensor really helped balance the heating in my home. After replacing our heater, the installer set up a new thermostat and included one remote sensor—but it didn’t quite solve the uneven heating across rooms. I decided to add another sensor myself, and honestly, the improvement was noticeable.The extra sensor made a big difference in creating a more consistent temperature, especially between floors. Now, I’m even considering adding a third one to help regulate the heat in our finished basement. Setup was simple, and it paired easily with our Honeywell thermostat. If you’re dealing with hot and cold spots, this sensor is absolutely worth trying.

I was skeptical this would actually valance the air in my new home. One bedroom was reading 70 degrees with the thermostat set on 74. Installed these sensors and what a difference. That rooms stays cooler now and the ac doesn’t seem to be running more- it seems to running less.