The discharge air high limit switch is located inside the air discharge compartment (grill area). This limit switch helps protect against the heating of objects which may obstruct the air discharge area or violate grill clearances.
If normal operating temperature is exceeded, this switch opens and interrupts power to the control circuit. The discharge air system is disabled and the heater’s control panel display no longer illuminates. If the switch opens repeatedly, verify grill clearances are not violated and complete the Air Discharge Check-Out Procedure.
NOTE: It is uncommon to see a failure in this part. If the limit switch is opening repeatedly, the Air Discharge Check-Out Procedure should be completed.
NOTE: Auto reset and manual reset limit switches are not interchangeable. The limit switch used as a replacement MUST be the same style and type as the limit switch the heater was manufactured with. Heaters with serial number ending in “095580” or lower use auto reset limit switches. Heaters with serial number ending in “095581” or higher use manual reset limit switches.
Links
Auto Reset
Manual Reset