Trane Mini Split 7-TIME BLINK Error Code

Updated 2026-08-29 · review status: manual-verified Last verified: 2026-08-29

Quick answer

7-TIME BLINK on Trane mini splits means outdoor control system trouble - the inverter PCB or outdoor PCB cannot read data in its nonvolatile memory. Power cycle once at the breaker; if the pattern returns, the outdoor board needs a technician.

Severity: high · DIY difficulty: beginner

Safety

Stop here: electrical or inverter work is technician-only. Do not open panels, test capacitors, touch wiring, connect gauges, add refrigerant, or keep resetting the system.

What 7-TIME BLINK means

Trane's troubleshooting table lists 7-TIME BLINK as outdoor control system trouble. The service manual says the inverter PCB or outdoor electronic control PCB cannot read data in nonvolatile memory; the manual directs checking the outdoor board LED pattern and board replacement as the remedy.

Code meaning varies by series

  • Trane ML series (Mitsubishi-built NTXWMT/NAXWMT) service manual: Outdoor control system nonvolatile-memory read failure - same fault also shows as the upper lamp lighting up steady with the outdoor unit not operating; manual remedy is inverter/outdoor PCB replacement

Causes, ranked

  1. 1. One-time control glitch that clears on power cycle occasional diy-ok

    Check: Power cycle the system once at the breaker or disconnect if you can do that safely. Do not open the outdoor unit.

    Fix: If the code does not return, monitor; if it returns, stop resetting and schedule service.

  2. 2. Outdoor/inverter PCB nonvolatile memory (EEPROM) corruption occasional pro-only

    Check: Memory verification needs service-tool diagnosis.

    Fix: Technician: confirm the fault and replace the inverter or outdoor control PCB.

  3. 3. Outdoor PCB hardware failure occasional pro-only

    Check: Board-level inspection required.

    Fix: Technician: replace the failed outdoor board.

  4. 4. Outdoor board LED indicates a different underlying fault occasional pro-only

    Check: Reading the outdoor board LED pattern requires opening the panel.

    Fix: Technician: cross-check the outdoor LED blinking pattern to pinpoint the fault before replacing boards.

Related codes

trane/3-time-blink · trane/4-time-blink · trane/5-time-blink · trane/6-time-blink · trane/upper-lamp-0-5-second-blink

Commonly searched as: "trane 7-time blink" · "trane error code 7-time blink" · "trane air conditioner 7-time blink"

Sources

  • Trane error codes (upper lamp blink table) - SplitAtlas, sourced from Trane MyLinkDrive NTXWMT-A111A(B) Service Manual Section 9 — verified 2026-08-29
  • Mitsubishi Electric / American Standard NAXSMT-A111AA (Trane ML-series equivalent) Service Manual, 9-4 Troubleshooting Check Table — verified 2026-08-29