How to Reset a Mini-Split After a Power Outage

Updated 2026-08-29 · topics: Power & electronics · General reference

Quick answer

Turn the unit off with the remote, switch off the outdoor-unit breaker for 5 minutes, then restore power and restart. Most mini splits resume normally after a clean power cycle — but error codes that survive a reset point to a real fault, not a glitch.

Do this first (works for nearly every brand)

If the breaker trips again immediately when you restore power, stop and leave it off — that indicates a short (compressor, board, or wiring) and needs a technician.

  • Stop the unit with the remote. Press the ON/OFF button so the indoor unit isn't trying to run while you cut power.
  • Switch off the breaker that feeds the outdoor unit. Mini splits feed both indoor and outdoor units from this single breaker — that's why the breaker matters and the remote alone isn't enough.
  • Wait a full 5 minutes. The inverter board holds charge in its capacitors; this wait is what actually clears the fault memory on most brands.
  • Restore power and turn the unit on. Set a moderate temperature (24°C / 75°F) and watch the display for 10 minutes.

    • That's the whole procedure. On the majority of units this clears outage-related faults: memory-glitch codes, brief over/under-voltage trips, and stuck communication states.

    Brand quirks worth knowing

  • Midea / MRCOOL / Senville: these share Midea platform behavior. If the unit has a wired controller, hold the CHECK/ECO button sequence shown in your controller's manual to view stored codes after a reset — an outage often leaves the last fault in memory even though the unit runs.
  • Gree / Tosot / Trane-legacy (Gree OEM): power-cycling clears the code display, but Gree boards keep the fault log. If the same code returns within a few days, treat it as an active fault, not an outage symptom.
  • LG: after a clean power cycle, a CH error that returns instantly (within seconds of startup) usually indicates a hard fault — CH05/CH10-family communication codes after outages often trace to a grounded or damaged outdoor wiring run that the surge stressed.
  • Daikin: the remote sensor check (hold CANCEL or the check button per model) shows stored codes as U4/E5-family history. Daikin units that ran during a brownout commonly log E5 (compressor overload) once and then run fine.
  • Fujitsu / Mitsubishi-style rotary dials: no menu reset exists — the 5-minute breaker procedure is the reset.

    • What a reset will NOT fix

    Never reset a unit that shows a refrigerant or pressure code more than once. Repeated restart-into-fault cycles can destroy a compressor that a single service call would have saved.

  • Codes that return immediately on power-up (sensor open/short, board memory failures).
  • Refrigerant-pressure codes (E5-family on many brands) — these trip because of a real pressure condition, and repeatedly resetting stresses the compressor.
  • Burning smell, tripping breaker, or buzzing from the outdoor unit — these are stop-use conditions, not reset conditions.

    • The honest rule: a reset is a diagnostic, not a repair. One clean reset is informative; three resets in a row is how a small fault becomes a board replacement.

    After the reset: watch for these codes

  • Communication codes (E6/E7, CH05, EE, EC51-family): the outage may have stressed the inter-unit wiring or a surge damaged a board. Check the units both run before assuming the worst.
  • Sensor codes (E1/E2-family): a brownout can corrupt a sensor reading; if the code clears and stays clear for a full day, ignore it.
  • EEPROM/memory codes: these indicate board-level damage from the surge — the board usually needs replacement, which is a technician job.

    • Find your exact code in the brand list, and check the code's page for its verified meaning before buying parts.

    Prevent it next time

  • A surge protector sized for mini splits (surge-rated at the disconnect box) is cheap insurance — outage-related board damage is one of the most common non-warranty failures.
  • If outages are frequent in your area, ask an electrician about a delayed-restart kit — many boards support a 3-minute random-start delay that protects the compressor from short-cycling when power returns.

    • Tools & parts for this fix: mini split surge protector disconnect

    Amazon →

    Error codes related to this guide

    Codes that commonly appear after an outage — and that mean the reset did NOT clear the problem:

    Related guides

    Mini-Split Communication Error: DIY Checks Before a Tech Call · Mini-Split Error Code Prefixes: What E, F, H, P Mean · Mini-Split Flashing Light Decoder: What the Blink Pattern Means

    Beyond the DIY line? This fix involves sealed-system or mains-voltage work — a licensed technician is the safe call.

    HVACDirect →  ·  Find local HVAC pros →

    Sources

    • Midea/MRCOOL DLFSHB service manual (reset & fault-log procedures) — verified 2026-08-29
    • Gree service manuals — fault memory retention behavior — verified 2026-08-29
    • LG official support — CH-series communication error procedures — verified 2026-08-29
    • Daikin service manuals — E5 compressor overload / stored-code display — verified 2026-08-29