Possible Cause | Possible Solution |
| Incorrect wiring | Correct the wiring. |
| Switch-on setting for stage incorrect | Adjust the setting. |
| Relay set to cool for a heater | |
| Relay set to heat for a fan | |
No power to load | Switch on the power. |
Faulty equipment | Replace the equipment. |
Circuit breaker open | Reset the breaker. |
Blown relay | Solve the problem that
caused the relay to blow and then replace the circuit board or use a different
relay. |