Tempstar 2 Flashes

What does Tempstar 2 Flashes mean?

On a Tempstar packaged gas/electric unit, the integrated gas unit controller (IGC) LED flashing twice indicates a flame sense fault. Table 5 of the installation manual lists two flashes as the status code for this condition, meaning the control could not reliably detect or prove the burner flame during the heating sequence.

Symptoms

• IGC LED flashes twice instead of staying continuously on
• Burners light briefly then shut down, or fail to stay lit
• Unit cannot sustain a gas heating cycle
• Indoor fan behavior interrupted during heating

Common causes

• Flame sensor not detecting an established flame
• Weak, dirty, or misaligned flame sensing path
• Insufficient or unstable burner flame
• Wiring or connection issue between the sensor and the IGC

Diagnostic steps

1. 01

   Confirm the LED code

   Remove the control access panel and verify the IGC LED is flashing twice, identified in Table 5 as a flame sense fault.

2. 02

   Observe the burner flames

   With the access panel removed, watch the burner flames; the manual states they should be light blue, soft, and approximately the same on each burner.

3. 03

   Check the heating sequence

   Verify that on a call for heat the induced-draft motor runs its pre-purge and the burners attempt to light, then note where flame detection fails.

4. 04

   Cycle power to clear the fault

   After correcting the flame issue, break the call for heat and restore it to allow the IGC to re-attempt its ignition sequence.

When to call a professional

Call a qualified service technician if the flame sense fault persists, since diagnosis involves the flame sensing circuit, gas valve, and ignition components. The manual states the unit should be serviced by a qualified technician equipped with proper tools and test instruments, and warns against jumpering any safety device. Do not attempt repairs to the gas or ignition system without the right training.