Condition
AC Has No Power at All
Unit is completely dead—no lights, no fan, no response. Electrical supply or thermostat issue.
Possible Causes
Incorrect Thermostat Calibration
If the thermostat fails to sense the correct temperature, it won't signal the HVAC to run.
Root Cause Analysis →Diagnostic Tests
- Check 24V at thermostat
- Jump R to Y/G
- Verify battery
Repair Options