| Symptom | Problem | Solution |
|---|---|---|
| The A25 is not sensing properly. | The sensing element may not be extended into the airstream or the sensing element is contacting an object inside of the duct (or plenum). | Insert the sensing element as far as possible into the airstream without allowing it to contact any object inside the duct (or plenum). |
| The system does not operate. | Incorrect switch connections or
improper wiring.
Damaged sensor. The A25 is tripped. |
Ensure that the wiring
connections follow the wiring diagrams in the Wiring
section.
Check connections. Replace the A25. Reset the A25. |
| A25 does not lockout upon a temperature rise beyond the setpoint. | The A25 is defective. | Replace the A25. |
| The A25 does not sense the correct air temperature. | The A25 is defective. | Replace the A25. |
| A25 will not reset. | The temperature in the duct (or plenum) is not 20F° (11C°) below the setpoint. | Check system for overheating or fire. |