Tempstar 3 Flashes

What does Tempstar 3 Flashes mean?

On a Tempstar packaged gas/electric unit, the integrated gas unit controller (IGC) LED flashing three times indicates four consecutive limit switch faults. Per Table 5 of the manual, this escalated status code appears when the limit switch has repeatedly opened on high leaving-air temperature within a short span, signaling an ongoing overheat condition rather than a single trip.

Symptoms

• IGC LED flashes three times instead of staying continuously on
• Repeated interruption of gas heating
• Blower runs while burners are shut off
• Heating performance is poor or intermittent

Common causes

• Persistently restricted or inadequate heating airflow
• Dirty filter or blocked supply and return ducts
• Blower motor or speed setting not matched to the heating load
• Temperature rise consistently above the approved range

Diagnostic steps

1. 01

   Confirm the LED code

   Remove the control access panel and verify the IGC LED is flashing three times, which Table 5 defines as four consecutive limit switch faults.

2. 02

   Restore proper airflow

   Replace a dirty filter and open any closed registers so the unit can produce a temperature rise within the range stamped on the rating plate.

3. 03

   Verify blower operation and speed

   Confirm the blower runs at the correct heating speed; the manual notes the high speed is for high-static cooling only and must not be used for gas heating on single-phase units.

4. 04

   Clear the fault and retest

   After correcting airflow, cycle the call for heat and watch the LED to confirm normal continuous operation returns.

When to call a professional

Call a qualified service technician if three flashes continue after airflow and blower speed have been verified. Repeated limit trips point to a deeper airflow, blower, or heat exchanger problem that needs professional diagnosis. The manual states this equipment must be serviced by a qualified technician with proper tools, and warns that jumpering safety devices is unsafe.