Mitsubishi heat pump Wi-Fi control comes two ways in NZ: Mitsubishi Electric’s own Wi-Fi Control adapter and app, fitted by an installer and run through the cloud, or a small ESP32 board plugged into the indoor unit’s CN105 port for local control in Home Assistant. This guide covers both, plus infrared blasters, for owners and tinkerers.
The DIY route has a local backstory. In October 2016, Hadley Rich published “Hacking a Mitsubishi Heat Pump / Air Conditioner” on the original nicegear blog at this address, documenting the CN105 serial port; readers built on it to create the SwiCago HeatPump library, which still credits that post. If smart homes are new to you, our home automation basics explain the building blocks first.
Key takeaways
- Official route: a Mitsubishi Electric Wi-Fi adapter such as the MAC-588IF-E (or Wi-Fi built into newer models) plus the Mitsubishi Wi-Fi Control app. It is installer-fitted, works with Alexa and Google Home, and needs the internet and a 2.4 GHz network.
- DIY route: an ESP32 on the CN105 port running the open-source MitsubishiCN105ESPHome component gives fast, two-way local control in Home Assistant, with no cloud.
- CN105 is a 5 V serial port (2400 baud, even parity). ESP32 pins are 3.3 V only, so a logic level shifter is required.
- Opening the indoor unit exposes 230 V parts. Isolate the power first, and remember that Mitsubishi does not support third-party hardware.
- IR blasters need no modification, which suits renters, but they cannot confirm what the heat pump actually did.
Which Mitsubishi Wi-Fi control route suits you?
Answer seven quick questions to compare the official Mitsubishi Electric Wi-Fi Control adapter, a local ESP32 on the CN105 port, and an infrared (IR) blaster.
Our editorial weighting, not advice from Mitsubishi Electric. The ESP32 route uses community software (SwiCago/HeatPump and MitsubishiCN105ESPHome) that Mitsubishi does not support. Always isolate the power before opening a heat pump.
In this guide
How to connect a Mitsubishi heat pump to Wi-Fi: the official route
Mitsubishi Electric NZ calls its system Wi-Fi Control. It is compatible with the company’s domestic high-wall, floor console and ducted systems, and comes either built in (on some newer models, such as the Designer EF series) or as an adapter that plugs into the indoor unit. Current adapters include the MAC-588IF-E and MAC-578IF-E, with the older MAC-568IF-E, MAC-559IF-E and MAC-558IF-E still in many homes. Mitsubishi says the adapter should only be installed by an authorised installer, so ask for a supplied-and-fitted price.
- Check compatibility on Mitsubishi Electric’s model list, or ask your installer.
- Get the adapter fitted, or confirm your model has Wi-Fi built in.
- Install the Mitsubishi Wi-Fi Control app from the App Store or Google Play and create an account.
- Join it to your Wi-Fi. Mitsubishi requires a WPA2-AES router with the 2.4 GHz band switched on, and an active internet connection.
- Add voice control if you want it: Wi-Fi Control works with Amazon Alexa and Google Home.
Indoor units often sit high on a wall at the far end of the house, where Wi-Fi is weakest. If the adapter keeps dropping out, improve coverage first, for example with a mesh Wi-Fi system, before blaming the heat pump.
MELView NZ vs MELCloud
Search for Mitsubishi heat pump apps and you will find two cloud services. The Mitsubishi Wi-Fi Control app used in NZ and Australia runs on Mitsubishi’s MELView service, while much of Europe uses MELCloud. The accounts are not interchangeable, which is why European guides, and Home Assistant’s built-in MELCloud integration, do not help with NZ units. Community-made MELView integrations for Home Assistant exist, such as ha-melview-custom, but they rely on the same cloud service and can break when Mitsubishi changes it.
Mitsubishi CN105: how the local hack works
Inside most Mitsubishi indoor units, the control board has a small five-pin socket labelled CN105. It is the same port the official Wi-Fi adapters use, and it speaks a simple serial protocol: 5 V TTL levels at 2400 bits per second with even parity. Because the link is two-way, the heat pump reports its real state, including changes made with the handheld remote, so your app never has to guess.
That is what Hadley’s 2016 project worked out with a logic analyser, bridging the heat pump to an MQTT broker from a Raspberry Pi 2. In the comments, a reader known as AL ported the protocol to an Arduino library, which became SwiCago/HeatPump. The geoffdavis/esphome-mitsubishiheatpump project later wrapped that library for ESPHome, and when it was archived in March 2025 its maintainer pointed users to Eric Chavet’s MitsubishiCN105ESPHome, today’s recommended option. Hacking a Mitsubishi heat pump has gone from a logic-analyser project to a few lines of YAML.
| CN105 pin | Signal | Use |
|---|---|---|
| 1 | 12 V | Not used |
| 2 | GND | Ground |
| 3 | 5 V | Can power the ESP32 board |
| 4 | TX | Data from the heat pump (5 V) |
| 5 | RX | Data to the heat pump (5 V) |
What you need for an ESP32 heat pump controller
- An ESP32 board. The MitsubishiCN105ESPHome project recommends ESP32 devices such as a generic ESP32 dev kit, M5Stack ATOM Lite or ATOM S3 Lite, or Seeed XIAO ESP32S3, and warns that ESP8266 boards tend to be unreliable. Our Arduino vs ESP32 vs Raspberry Pi guide explains why the ESP32 suits jobs like this.
- A bidirectional logic level shifter. The heat pump side is 5 V and ESP32 pins are not 5 V tolerant, so do not wire them directly.
- A JST PA five-pin plug. The SwiCago README lists the PAP-05V-S housing with SPHD-002T-P0.5 crimp terminals; pre-crimped leads save fiddly crimping.
- Somewhere to run ESPHome and Home Assistant, such as a Home Assistant Green.
ESPHome configuration
The component installs straight from GitHub as an ESPHome external component. These are the key parts of the project’s own example; pin numbers depend on your board, so follow the README for your hardware:
# Key parts of the MitsubishiCN105ESPHome README example (ESP32 DevKit pins).
# Add your usual esphome, esp32, wifi, api and ota sections.
uart:
id: HP_UART
baud_rate: 2400
tx_pin: GPIO17
rx_pin: GPIO16
external_components:
- source: github://echavet/MitsubishiCN105ESPHome
climate:
- platform: cn105
name: "My Heat Pump"
update_interval: 2sOnce flashed and adopted, Home Assistant shows the heat pump as a climate device with mode, target temperature, fan speed and vane controls, updating within a couple of seconds. Everything stays on your network, so it keeps working when the internet is down.
Mitsubishi heat pump Home Assistant options compared
| Hardware | MAC-588IF-E adapter, or built in | ESP32, level shifter, JST PA lead | Smart IR hub, or an ESP32 with an IR LED |
|---|---|---|---|
| Fitting | Authorised installer | DIY, inside the indoor unit | Sits in the room, no wiring |
| Feedback | Two-way | Two-way, local | One-way, no confirmation |
| Without internet | No | Yes | Usually, depending on the hub |
| Home Assistant | Community cloud integrations | Native through ESPHome | Hub integration or ESPHome IR climate |
| Support | Mitsubishi Electric | Community only, at your own risk | Hub maker; heat pump untouched |
| Voice control | Alexa and Google Home | Through Home Assistant | Through the hub’s app |
Safety, warranty and renting
Isolate the power before you open anything
The CN105 socket carries only 5 V and 12 V, but it sits on a control board inside a unit with 230 V wiring. Switch the heat pump off at its isolating switch (often mounted by the outdoor unit) and at the switchboard before removing covers, and do not rely on the remote’s off button. If you are not confident working inside an appliance, ask your installer to fit the official adapter instead.
Mitsubishi Electric does not support third-party boards on CN105, and the MitsubishiCN105ESPHome project itself describes the code as an unofficial, reverse-engineered implementation to use at your own risk. If a fault is traced to your add-on, do not expect warranty help; many owners wait until the warranty period has passed. Renters should leave the heat pump alone: it is the landlord’s appliance, and an IR blaster gives you app control without touching it.
IR blasters: the no-screwdriver option
A smart IR remote, such as a Broadlink or SwitchBot hub, learns or reproduces the codes your handheld remote sends, so you can control the heat pump from your phone and Home Assistant without opening anything. DIYers can do the same with an ESP32 and an IR LED, using ESPHome’s IR climate component, which includes a Mitsubishi platform.
The weakness is that IR is one-way. The blaster needs line of sight, cannot tell whether the unit heard it, and loses track if someone uses the real remote. For simple schedules that is often fine; for automations that depend on the actual state, CN105 is better.
Common mistakes with heat pump Wi-Fi control
- Switching a heat pump with a smart plug. Heat pumps are hard-wired, and cutting their power is not a way to control them. Use Wi-Fi control or IR, and save smart plugs for plug-in appliances.
- A 5 GHz-only network. The official adapter and ESP32 boards both need 2.4 GHz Wi-Fi.
- Skipping the level shifter. Wiring 5 V serial lines straight to an ESP32 risks damaging the board and confusing the heat pump.
- Automations that fight people. A rule that resets the temperature every few minutes overrides anyone using the remote; trigger on events such as arriving home instead.
- Heating an empty house. Wi-Fi control pays off when you schedule it: a heat pump is usually the biggest winter load, so pre-heat before you get home rather than leaving it on all day.
Our home energy monitoring guide shows how to measure what your heat pump actually uses, and if you have solar, running it harder while the panels are producing makes the most of your own power; the solar panel and battery calculator covers the numbers. For more gadgets that play nicely with Home Assistant, see our smart home devices guide.
Our take
- If you just want to control your heat pump from your phone, the official Mitsubishi Electric Wi-Fi Control adapter is the sensible, supported choice, and newer models may already have it built in.
- If you run Home Assistant and are comfortable with electronics, an ESP32 with a level shifter on CN105, running MitsubishiCN105ESPHome, is faster, fully local and far more flexible.
- Renters, or anyone who would rather not open the unit, should use an IR blaster.
- Whichever you choose, isolate the power before opening a heat pump, and schedule heating rather than leaving it running.
Product details were checked against Mitsubishi Electric NZ and the community projects’ documentation in September 2026. The CN105 method is unofficial and done at your own risk. Nicegear is independent, sells nothing and has no paid placements.
Sources and further reading
- Wi-Fi Control – Mitsubishi Electric New Zealand
- MAC-588IF-E Wi-Fi Interface – Mitsubishi Electric New Zealand
- SwiCago/HeatPump Arduino library – GitHub
- echavet/MitsubishiCN105ESPHome – GitHub
- geoffdavis/esphome-mitsubishiheatpump (archived) – GitHub
- IR Remote Climate – ESPHome documentation
- Hacking a Mitsubishi Heat Pump / Air Conditioner (October 2016) – original nicegear blog, Internet Archive copy
FAQs
How do I connect my Mitsubishi heat pump to Wi-Fi?
Check that your model is compatible, have an authorised installer fit a Mitsubishi Electric Wi-Fi adapter such as the MAC-588IF-E (some newer models have Wi-Fi built in), then set it up in the Mitsubishi Wi-Fi Control app on a 2.4 GHz WPA2 network.
What is the CN105 port on a Mitsubishi heat pump?
It is a five-pin JST PA connector on the indoor unit’s control board carrying 12 V, ground, 5 V and a two-way serial link at 2400 baud with even parity. Mitsubishi’s own Wi-Fi adapters use it, and so do community ESP32 controllers.
Can I use Home Assistant with a Mitsubishi heat pump in NZ?
Yes. The most reliable way is local, with an ESP32 on the CN105 port running MitsubishiCN105ESPHome. Community-made MELView integrations also exist, but they depend on Mitsubishi’s cloud, and Home Assistant’s built-in MELCloud integration is for the European service.
What is the difference between MELCloud and MELView?
Both are Mitsubishi Electric cloud services for Wi-Fi-connected heat pumps. MELView sits behind the Mitsubishi Wi-Fi Control app in NZ and Australia, while MELCloud is used in Europe, and accounts are not interchangeable.
Will an ESP32 CN105 controller void my warranty?
Mitsubishi Electric does not support third-party hardware on CN105, so a fault caused by an add-on is unlikely to be covered. Check your warranty terms, and consider waiting until the warranty has expired before fitting one.
Can I control my heat pump from my phone without opening it?
Yes, with a smart IR blaster that copies your remote’s signals, or with the official adapter fitted by an installer. IR control is one-way, so it cannot confirm the heat pump responded.
Does Mitsubishi Wi-Fi Control work with Alexa and Google?
Yes. Mitsubishi Electric NZ says its Wi-Fi Control, built in or added with an adapter, works with Amazon Alexa and Google Home.
