CT101 Thermostat not communicating well with repeaters

I’m trying to relocate my CT101 (with Rboy DTH) to my detached garage. I have extended my zwave mesh there with some zwave devices. They work reliably in the garage now.

But I cannot get the thermostat to respond up there. If I change the setpoint or mode in the mobile app, it does eventually change but changes on the thermostat do not reflect back to the hub.

I have tried several resets, running on the C wire, running on battery, zwave repairs, etc. Is there some weird issue where Zwave Plus devices don’t repeat for older non-plus devices? I don’t have any other non plus devices to test up there.

Z-Wave has a limitation of 4 hops and older devices do have some trouble with many hops, typically noted by delayed messages like you’re seeing. Check how many active devices you have between your thermostat and your hub.

Also try to hit the “reset” button on the thermostat (a little black button next to the wire terminals), sometimes that helps kick some sense into the thermostat and it behaves itself :wink:

Remember if you’re adding a C-wire, for it to take effect you need to exclude and re pair the thermostat with the C wire attached, otherwise it goes into sleepy mode with batteries only (which does lead to dropped commands at time).

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I count 3 or 4 hops to the stat depending on what route it may take.

This unit was originally in the house and running on a c wire. I may have reset it while it was running on batteries, but now I have it on a c wire up in the garage.

Maybe I need to try to exclude and include it. If it’ll repair from up there that is.

So I played around a little more over the weekend. I tried to remove the CT101 from ST but ended up having to force remove it, then reset the thermostat. I was using the method of setting it to off, hit menu, hold the center of the screen 5s, press up, wait for countdown, press up, wait for countdown.

But now I can’t seem to get the bugger to re-pair with ST.

Any tricks to try?

When you removed it from ST you didn’t exclude it so the device thinks it’s paired and won’t pair again. Reset doesn’t reset the pairing of the thermostat.

Fortunately it’s simple, put your hub into exclusion mode from the the ST Mobile App → location → Settings → Hub utilities → General Exclusion, then follow the exclude thermostat procedures. You should receive a confirmation on your ST app that a device was excluded. Once that’s done now pair it.


Did the exclusion and got the notification in the ST app when I did the reset.

Repaired it like a new device and ST picked it right up using your DH right from the get-go.

But I’m still in the same boat as before. The dang thing just won’t report back to the hub. The inclusion/exclusion communications worked okay. It also eventually gets the time right, but still shows 0 degrees in the app and nothing but the battery age lines in live logging.


Then you may have a defective z-wave module, see if you can get a replacement from the manufacturer