Mitsubishi Comfort Integration for Home Assistant

Home Assistant integration for Mitsubishi Electric climate systems that use the Kumo Cloud / Comfort cloud service (API v3). Provides full climate control, multi-zone support, and per-zone temperature, humidity, diagnostic, and wireless-sensor entities.

Features

• Full climate control: target temperature, HVAC mode, fan speed, vane position
• Heat, Cool, Dry, Fan-only, and Auto (HEAT_COOL) modes with dual setpoints in Auto
• Per-zone temperature and humidity sensor entities
• Wireless sensor support (PAC-USWHS003-TH-1): battery, signal strength, temperature, humidity — auto-detected via the zone's hasSensor flag
• Diagnostic sensors: WiFi adapter firmware version, WiFi signal strength, filter maintenance reminders
• Comfort-app-accurate fan speed and vane position labels (no raw API strings surfacing in the UI)
• Mitsubishi-accurate Fahrenheit/Celsius conversion (no setpoint drift)
• HVACAction.IDLE reported when a zone is at setpoint, so tiles, energy dashboards, and automations don't see a unit as always heating/cooling
• Command caching to prevent state bouncing while the cloud API catches up (the API can lag the actual device by up to a minute)
• Automatic token refresh, rate-limit handling with exponential backoff, graceful degradation through transient API failures
• Remembers the last HVAC mode you set, so toggling a unit off and back on through the HA UI restores your previous mode instead of defaulting to cool
• DHCP discovery: when a Mitsubishi WiFi adapter joins the LAN, HA's "Discovered" panel surfaces the integration as a setup prompt
• HA Download Diagnostics support on the integration and device pages, with credentials, tokens, serials, and MACs redacted

Supported devices

Any Mitsubishi Electric indoor unit paired with a Kumo Cloud / Comfort cloud adapter and visible through the Mitsubishi Comfort app. Optional PAC-USWHS003-TH-1 wireless temperature/humidity sensors are detected automatically.

Installation

HACS (recommended)

1. Install HACS if you haven't already
2. Go to HACS → Integrations → ⋮ menu → Custom repositories
3. Add JoeQuantum/comfort_HA with category Integration
4. Search for Mitsubishi Comfort and install
5. Restart Home Assistant

Manual

1. Copy custom_components/kumo_cloud/ into your Home Assistant config/custom_components/ directory
2. Restart Home Assistant

Configuration

1. Go to Settings → Devices & Services → Add Integration
2. Search for Mitsubishi Comfort
3. Enter your Kumo Cloud / Comfort app credentials
4. Select a site if your account has more than one

All zones in the selected site are discovered automatically. A re-auth prompt appears if your password changes; you don't need to delete and re-add the integration.

If a Mitsubishi WiFi adapter is already on your network when HA boots, the integration will also appear in Settings → Devices & Services → Discovered as a one-click setup prompt.

Entities created

Per zone:

Entity	Notes
climate.<zone>	Full climate control. Exposes current_temperature, current_humidity (when the API reports it), target setpoint(s), HVAC mode, fan speed, vane position
sensor.<zone>_temperature	Room temperature
sensor.<zone>_humidity	Room humidity (when reported)
sensor.<zone>_firmware	WiFi adapter firmware version (diagnostic)
sensor.<zone>_wifi_signal	WiFi adapter RSSI (diagnostic)
sensor.<zone>_filter_reminder	Next filter maintenance date (diagnostic)

When a PAC-USWHS003-TH-1 wireless sensor is attached:

Entity	Notes
sensor.<zone>_wireless_sensor_battery	Battery level
sensor.<zone>_wireless_sensor_signal	Wireless sensor RSSI
sensor.<zone>_wireless_sensor_temperature	Wireless sensor temperature
sensor.<zone>_wireless_sensor_humidity	Wireless sensor humidity

All entities for a given indoor unit are grouped under a single HA device. The device page shows the model (e.g. MSZ-FH09NA), the unit's firmware (serialProfile), and the serial number reported by the Comfort cloud.

Behavior notes

HVAC idle inference

The Kumo Cloud V3 API does not expose a "compressor running" signal — only the configured operation mode and power state. Without inference, hvac_action would report HEATING/COOLING continuously whenever a unit is on in that mode, which is wrong for tile glow, energy dashboards, history graphs, and any automation keyed on hvac_action.

The integration infers HVACAction.IDLE from the current vs. target temperature delta: in HEAT, COOL, AUTO_HEAT, and AUTO_COOL, it flips to IDLE once the room is past setpoint by 1.0 °F. This is a proxy — inverter mini splits modulate, so a unit reading IDLE may still be drawing a small amount of power.

Command caching

The Comfort cloud API can take up to a minute to reflect a command. The integration caches commands locally with a timestamp and keeps them applied to the entity state until the server's updatedAt field confirms the command was processed. This eliminates the visible "bounce" where a slider would snap back to its previous value a second after you moved it.

Temperature conversion

Mitsubishi systems store temperatures in 0.5 °C steps but use a proprietary Fahrenheit-to-Celsius mapping that diverges from standard arithmetic at several setpoints (64–66 °F and 69–72 °F). The integration uses Mitsubishi's lookup table for setpoints and display, eliminating the ~1 °F drift that standard rounding causes for Fahrenheit users. Values outside the lookup table fall back to standard conversion.

Authentication failures

A 403 from the Kumo Cloud API raises KumoCloudAuthError, which Home Assistant maps to ConfigEntryAuthFailed — surfacing the re-authentication prompt in the UI rather than entering a retry loop.

Comparison to other Mitsubishi integrations

Several Home Assistant integrations talk to Mitsubishi mini-splits. They make different tradeoffs; pick whichever matches your setup.

vs. HA Core mitsubishi_comfort (shipping in 2026.6)

Home Assistant Core gained a first-party mitsubishi_comfort integration in May 2026, expected in the 2026.6 release. It also talks to the Kumo Cloud V3 API and is maintained as part of HA Core.

Choose mitsubishi_comfort if you want the lowest-maintenance path and only need climate control. Bugfixes ship with Home Assistant releases.

Choose this integration if you also want:

• Per-zone standalone temperature and humidity sensor entities, independent of the climate entity — usable in history graphs, templates, and automations without state_attr() indirection
• Wireless sensor (PAC-USWHS003-TH-1) entities: battery, signal strength, temperature, humidity
• Filter maintenance reminder sensor
• WiFi adapter firmware and signal strength as diagnostic sensors
• Last-mode memory across off/on cycles

Different domain names (kumo_cloud vs mitsubishi_comfort) mean both can be installed simultaneously without conflict.

vs. dlarrick/hass-kumo

hass-kumo is the long-running community integration. Architecturally it's local-first: it controls units over your LAN via the encrypted CoAP protocol (using the pykumo library), with the Kumo Cloud contacted only during initial setup.

Choose hass-kumo if you want:

• Local control — no cloud round-trips during normal operation; works during internet outages
• Outdoor temperature reporting from a Kumo Station accessory
• The Mitsubishi Kumo Station thermostat hub features

Choose this integration if you want:

• Pure cloud setup with no LAN requirements — your HA instance and your mini-splits don't need to be on the same network
• Standalone per-zone sensor entities (in hass-kumo these live on the climate entity's attributes)
• Filter maintenance reminders
• No pykumo dependency

Different domain names (kumo_cloud vs kumo) mean both can be installed simultaneously without conflict.

Fan Speed Reference

HA Label	Comfort App	API Value
auto	Auto	auto
quiet	Quiet	superQuiet
low	Low	quiet
medium	Medium	low
high	High	powerful
powerful	Powerful	superPowerful

Vane Position Reference

HA Label	Comfort App	API Value
auto	Auto	auto
swing	Swing	swing
lowest	Lowest	vertical
low	Low	midvertical
middle	Middle	midpoint
high	High	midhorizontal
highest	Highest	horizontal

Credits

Individual contributors

• jjustinwilson — Original integration and V3 API reverse engineering
• ekiczek — Mitsubishi F/C temperature lookup tables (PR #23, hass-kumo PR #199)
• smack000 — Command caching, coordinator refactor, sensor entities, auto heat/cool mode
• tw3rp — Dual setpoint support for auto heat/cool, improved entity availability, API rate limiting with exponential backoff
• greginno — Reported and prototyped the current_humidity property mapping
• mataiwilson — Identified and fixed the swallowed KumoCloudAuthError in login()

Patterns adapted from sibling projects

• dlarrick/hass-kumo — Diagnostics support, last-HVAC-mode memory pattern, DHCP MAC prefixes, pre-commit configuration, temperature-module extraction.
• HA Core mitsubishi_comfort (by @nikolairahimi) — KumoCloudEntity base class, ConfigEntry.runtime_data migration, hvac_action lookup-table style.

License

MIT — see LICENSE.