No. The Smart Thermostat HD cannot be powered by batteries. It requires a C wire for power.

No. Using a physical jumper can cause physical damage to the thermostat over time and cause the wire detection to complete incorrectly. The Smart Thermostat HD has an internal jumper between RH and RC. The internal jumper closes if there is only one wire in RH and nothing in RC.

When wire detection is completed incorrectly due to a physical jumper between RH and RC, the following HVAC problems can occur once the physical jumper is removed:

• The air conditioner will not turn on when the thermostat is in Cool Mode.
• Fan control will not function despite thermostat settings.
• Heat Pump functionality will not follow thermostat settings.

Three components make up the Smart Thermostat HD: 

1. Trim plate
2. Thermostat (ADC-T40)
3. Display (ADC-T40-HD)

The Thermostat will mount on the wall using the trim plate, with wires inserted in the terminals, and the Display will mount onto the Thermostat using magnets.

When the Alarm.com Smart Thermostat HD (ADC-T40K-HD) loses power, the configuration, current set point, and current mode will remain preserved. 

The thermostat should resume normal operation based on those settings once power is restored. If operation does not resume upon the restoral of power, contact CORE Technical Support.

The Thermostat has mechanical wire detection in the wire terminals, meaning any terminal with a wire inserted will indicate there is a wire present during setup, even if the wire is unused by the HVAC system. Sometimes there are extra, unused wires present within the wire bundle at the wall.