This article explains what to do when a thermostat is showing offline or malfunction. This means that the thermostat has lost communication with the hub and will 1) not respond to remote commands to adjust temperature, or 2) send temperature / humidity notifications. It does NOT mean that the thermostat is broken or that your HVAC system is not working.
This applies to the following thermostats (pictures shown below):
ADC-T40k-HD or HQ
ADC-T2000 
Honeywell T6 
ADC-T25 
Step 1 - refresh the thermostat in the PointCentral online portal:
Login to the customer website (https://secure.pointcentral.com/loginpage.aspx) and go into the unit, and then click on the refresh icon in the thermostat card as shown below inside the red circle:
Give the thermostat a few minutes to refresh. If successful, you will see the temperature and mode displayed. If not successful, please move to the next step.
Step 2: power cycle the thermostat:
T2000, T25 or Honeywell T6: Remove the thermostat from the wall plate (it will pull straight off and leave the wire harness in place. Remove the batteries and replace the batteries with 4 fresh AA batteries. Securely reattach to the wall. If successful, you will see the temperature and mode displayed. If not successful, please move to step 3.
T40k-HD or HQ: the faceplate of the thermostat is magnetic and will detach from the thermostat body. Remove the face plate and make sure you can see a solid LED light on the faceplate. If the LED light is off then the HVAC system has lost power, please contact your property manager for an HVAC repair to restore power. If you see the light, then reattach the thermostat and let it boot up.
If thermostat still does not reconnect, then move to step 3.
Step 3: Delete and re-add the thermostat to the system.
Contact support@epropertycare.com for help doing this step. If your thermostat is far away from the hub you may need to install a repeater to strengthen the signal to the thermostat.