FieldBench
Carrier codes

Carrier

8-flash

Lockout

IGC 8-flash — example

Example: internal control / valve circuit on current CES rooftop stickers. Power-cycle once; if 8-flash returns, valve ohms then IGC.

Walk 8-flash in Diagnose

2 plates — walk the one on the cabinet

First check

1 Write the live code and watch one cycle

On Carrier 48FC read IGC (heat) + WeatherMaker unit board (cool / fan / economizer) before you pull power. Write 8-flash exactly. Watch one full sequence and note which step dies. 24 VAC at the valve during a known trial. Coil ohms vs the valve sticker.

Expect: Call: Occupied / G starts the indoor fan. Y1 is cool. W is gas heat. They are different boards in the same box.

The rest of the walkthrough is Diagnose.

On the plates

  • 24 VAC at the valve during a known trial. Coil ohms vs the valve sticker.
  • A 8-flash that clears on a power-cycle and never returns was a glitch. Repeating 8-flash is a part.
  • Do not keep swapping IGCs before you measure the valve.

Plates that use 8-flash

Same number, other makers

8-flash on Carrier is not the same code on these plates.