Aprilaire 8644C4 Thermostat Offline

[Don Cohen]

I have had the Control4 Aprilaire 8644C4 for a few years, and it has worked well.  A rare loss of connection, but otherwise fine.

I found this evening that while it worked in terms of controlling my HVAC - can put it on Cool, Heat, Adjust Temperature, etc. - it doesn't seem to be communicating with Control4.  I noticed that it was on my Sleep Preset in the middle of the day.  I touched the bottom of the 4 buttons on the right side, with the Star on it, but there is no response at all.  It shows as offline on a T3 and Android Control4 App

Troubleshooting steps:

Rebooted the Controller (EA-3) as well as the EA-1 which serves as the Zigbee server
Physically removed the front of the Thermostat, popped one battery.
Attempted the various button press combinations to Identify (4 top), Reboot (15 top), Leave Mesh and Reset (13 top, 4 bottom, 13 top), and even Factory Reset (9 top, 4 bottom, 9 top).  But there is no response.  It's as if those buttons aren't registering.

In Composer Express, it shows as being Online in the Identification section, with Optimal signal strength.  But when I do an Action to Print Thermostat Status, it says "Thermostat is offline, no information is available at this time."

I manually disconnected it in Composer Pro Network connections (where it also showed as being Online), attempted to reconnect by 4 top button pushes, but no response.  I just manually re-entered the Address.  It shows there as Online, but yet it doesn't respond.

Is this a hardware failure, or is there something I can do to get it communicating again?  I have an identical Thermostat elsewhere in the home which works and connects fine.

Thank you.

[Don Cohen]

Update:

Looks like I needed to pop all 4 batteries, not just one of one pair.  Once I did that, the LCD went blank.  Left it that way for a little bit, and then reinserted the batteries.

Everything seems to be working now.

Weird....  I have no idea what might have triggered this, but it seems all is back to normal.

[Bill Piske]

I've had my thermostat for 4+ years and it recently went "off line". Any suggestions on troubleshooting, resetting and back "on line"?

[Cyknight]

Welp, see the above, remove from wall and remove all batteries. That said I would suggest 4 brand new batteries (don't use rechargeable for these devices) if you're removing them.

 

If that doesn't get it back, you may need to get a dealer involved to evaluate any zigbee issues.