I’m unable to get a new Honeywell T6 Pro Z-Wave thermostat (TH6320ZW) to connect (include) to my ISY 994i running 5.0.16C with Z-Wave version 6.81.00. I previously had a Trane XR524 that I was able to successfully connect to the ISY, but that stat took way too long to activate the furnace, often waiting until the house was 3 degrees below the set point before activating.

The Trane stat lost communication with the ISY, so I was unable to exclude it from the network properly, instead having to simply delete it. Then, because the Trane stat was my only Z-Wave device, I did a factory reset of the Z-Wave dongle.

After installing the new stat, I verified that it could control the furnace, so I know it’s wired correctly. I’ve tried 1) initiating Add/Include from the ISY followed by initiating the same from the new Honeywell stat, and 2) initiating the Add/Include from the stat followed by the same from the ISY. Neither way gets them connected. The stat runs through the “including” process” and then displays “Failed to include”.

Any advice on how to overcome this issue?

Have you run "exclude" first?

Many Zwave devices require exclude to be done before adding. I usually run exclude 2 times prior to attempting to add a device.

If that still doesn't work, try moving the ISY close to the thermostat and try adding in then. If that works, you might need to increase your mesh coverage by adding more devices.

I would also like to connect a Honeywell T6 Pro Z-Wave thermostat (TH6320ZW) to my ISY 994i.

Did you succeed?

 

Yes, I was indeed able to successfully connect my Honeywell T6 stat to my ISY 994i at my home. I also have a vacation rental home that has a 3-zone system, requiring 3 stats. I replaced all 3 with the Honeywell T6 and they work great. A small caveat is that at first the connection and communication weren't always successful. At my home I added a Z-Wave outlets (always on) between the stat location and the 994i location that made the connection rock solid. At the vacation home, because I have 3 stats, I added 2 Z-Wave outlets to help the connection. Again, that made for a rock solid connection to all 3 stats.

Another great thing about the Honeywell T6 is that it does a much better job controlling the temperature. The Honeywell is fantastic. I hardly give it a though because the house is always comfortable.

BTW, the 994i has to have the Z-Wave module added (super simple) and be at revision 5.0.16C (also super simple).