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

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.

Must have for a T9/T10 thermostat! Works very well with Home Assistant with local control over HomeKit. Each remote sensor is a separate addressable device with temperature, humidity, and occupancy entities.

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).

Easy to setup, and allows me to better control the temperature in a room far from my thermostat.

Make sure you check the series # of your T9 thermostat. I did not, thinking that as it is less than a year old it would be compatible. Wrong! Have had to buy the older version direct from Honeywell for $$$$$. Have 3 sensors already and they work well.

Have multiple of these installed in house. They work really well and I have always liked Honeywell. Will always deal with them because of quality. Item was shipped fast and very happy.

works very good!

I spent about 30 minutes trying to get this sensor to talk to the thermostat before giving up and doing the unthinkable- I called Honeywell for help. The good news is that they’re easy to get a hold of and are quite helpful. They have a web tool that lets you share video while on the phone with them, which makes it very easy to get support. The bad news- and why I can’t give this product a higher rating- is that even though this sensor is designed for T9 and T10 thermostats, it’s not compatible with MY T9 thermostat. My thermostat has a tiny “1” on the label (indicating it’s a first-gen T9) while the sensor has a tiny “3” (indicating it’s a third-gen T9 sensor). This is NOT indicated anywhere on Honeywell’s website or the product description and that’s a daggum shame.