Auto Reset
Manual Reset
The discharge air sensor (thermocouple) is connected to the discharge air thermocouple terminals on the processor control board and is then routed through the base of the heater to the air discharge area. This sensor monitors discharge air temperature to help maintain a constant discharge air temperature.
From the factory, this discharge air temperature is set to a maximum of 200°F/93°C. If the discharge air exceeds 285°F/140°C, the discharge air limit switch opens. If the discharge air temperature is less than 90°F/32°C (L048/C010), the blower only runs in low speed.
The discharge air sensor should be located within a 1/2" of the face of the discharge air high limit switch (see Air Discharge Check-Out Procedure). Refer to Location 111 (L111) for the current discharge air temperature as sensed by the discharge air sensor.
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.
Auto Reset
Manual Reset