Indoor Control System Memory Error

What does 4-time blink 2.5-second OFF mean?

This fault occurs when the indoor electronic control P.C. board cannot properly read data from its nonvolatile memory. It indicates a critical issue with the board's internal memory, which prevents the unit from retaining settings or executing operational commands. Without a functioning control board, the indoor unit will remain inoperable.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Ensure all connectors attached to the P.C. board are securely seated and free from loose contacts.

2. 4

   If the fault persists after these checks, the indoor electronic control P.C. board must be replaced.