E2 n 51 (FJM Indoor) — Compressor discharge sensor error (Short/Open)

What does E2 n 51 mean?

The FJM indoor unit displays E2 n 51, reporting an open or short circuit error with the compressor discharge sensor located in the outdoor unit. This means the indoor unit is detecting an outdoor unit problem.

• Faulty discharge sensor in the outdoor unit
• Loose sensor connection in the outdoor unit
• Communication issue from outdoor to indoor unit regarding sensor status

Click steps to track your progress.

1. 1

   Check the outdoor unit for any specific error codes displayed on its PCB, as the root cause is typically external.

2. 2

   Ensure the outdoor unit's power supply is stable and consistent.

3. 3

   Turn off the main power to the entire system for 10 minutes, then restore power.

4. 4

   If the problem persists, contact a qualified technician to inspect the compressor discharge sensor in the outdoor unit.