Cause
- One of the 18 VAC controller fuses (F1/F2) is open. Refer to Cd08.
| Components | Troubleshooting | Corrective actions |
|---|---|---|
| System Sensors | Check system sensors for short to ground. |
Replace defective sensor(s) |
| Wiring | Check wiring for short to ground. | Repair as needed. |
| Controller | Controller may have an internal short. | Replace controller, refer to Controller Service Section 6.23. |
