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Heat-pump diagnostics

Available readings depend on the indoor unit.

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Firmware	Where to find diagnostics	Reported data
HomeKit-compatible	Controller web interface	Compressor frequency, outside temperature, runtime hours, error codes, sub mode, and stage information.
ESPHome	Home Assistant, after adding Diagnostics through the generator	Nine sensors: compressor frequency, outside temperature, input power, energy use, runtime hours, heat-pump connection uptime, stage, sub mode, and auto sub mode.
Matter-compatible	Controller web interface	Compressor frequency, outdoor temperature, runtime, and error codes; these do not appear in Google Home, Alexa, or SmartThings.

Outside temperature comes from the outdoor unit. Stage and sub modes describe its operating state. ESPHome diagnostic entities are enabled for history graphs when added through the generator.

On HomeKit-compatible and Matter-compatible firmware, Heat Pump · CN105 shows "Error code E" followed by the indoor unit's code. Include it with Copy Diagnostics in a support request.

For error codes or missing data, follow CN105 troubleshooting.

Restart reasons and counters

On HomeKit-compatible and Matter-compatible firmware, About shows Wi-Fi Drops and Pump Link Drops since the last restart. Boots and Crashes count since the last factory reset.

Last Reset shows why the controller last started:

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Value	What it means
POWER_ON	Power was switched on or restored.
SW_RESTART	The controller restarted itself: after an update, a pairing or Wi-Fi reset, or Restart Device.
BROWNOUT	The supply voltage dropped too low. Check the power source and the cable connections.
PANIC, TASK_WDT, INT_WDT, WDT	The firmware crashed and restarted. Include the diagnostics text in a support request.

Device events

On HomeKit-compatible and Matter-compatible firmware, About > Device Events retains 24 events through restarts, newest first. Select Refresh to load new ones. Before the clock is set, timestamps show boot #N and time since startup.

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Event	What happened
BOOT	The controller started. The reason follows in parentheses, using the Last Reset values above.
CRASH	The controller restarted after a crash.
SAFE_MODE	Repeated crashes started safe mode.
OTA	A firmware update was installed.
CN105_LOST	The indoor unit stopped answering over the CN105 cable.
CN105_OK	The indoor unit answered again.
CN105_ERROR	The indoor unit reported an error code.
RECOVERY_AP	The backup setup network opened.
HK_RESET	App pairing was reset.
WIFI_CREDS	The saved Wi-Fi network changed. (erased) means it was erased.

Repeated CN105_LOST events point to the cable or connector; see CN105 troubleshooting.

Live log behavior

Diagnostics · Logs keeps the last 200 lines while the page is open. Closing it stops capture. Debug returns to Info after a restart.

Capture evidence while the problem happens

Follow Collect diagnostics for support. Include error codes as displayed; this manual does not translate Mitsubishi service codes.