Mitsubishi Electric Wi-Fi Interfaces
19 fault codes documented
App says 'unit was not found' — Wi-Fi Interface not communicating with home network
When trying to add a new unit in the app, receiving a 'unit was not found' message means the Wi-Fi interface has not successfully connected or is not communicating with your home Wi-Fi network.
LED 1 flashing — WPS pairing in progress (MAC-558/559 models)
On MAC-558/559 models, LED 1 flashing indicates that the Wi-Fi interface is attempting to connect to your Wi-Fi network via WPS (Wi-Fi Protected Setup).
MAC-558/559 LED 1 flashes 0.2 sec, LED 2 solid ON — WPS Activated (PIN)
On MAC-558/559 models, a very rapid 0.2-second flash of LED 1 with LED 2 solid ON signifies that WPS (Wi-Fi Protected Setup) PIN mode is activated. This mode uses a PIN for pairing, often through router settings.
MAC-558/559 LED 1, 2, and 3 flash at 0.5-sec intervals — Power ON or Software Download
On MAC-558/559 models, if all three LEDs (LED 1, LED 2, and LED 3) flash rapidly at 0.5-second intervals, it indicates that the unit has just been powered on or that new software is being downloaded.
MAC-558/559 LED 1 flashes 0.5 sec alone — Server/AP comm failed, Heat Pump comm failed
On MAC-558/559 models, a rapid flash of only LED 1 (0.5 seconds) indicates that communication has failed with both the server/access point and the Heat Pump. This is a comprehensive communication failure.
MAC-558/559 LED 1 flashes 0.5 sec, LED 2 solid ON — Server/AP comm failed, Heat Pump comm starting up
On MAC-558/559 models, a rapid flash of LED 1 (0.5 seconds) with LED 2 solid ON and LED 3 OFF indicates that communication with both the server and the access point has failed, while communication with the Heat Pump is still in the startup phase.
MAC-558/559 LED 1 flashes 0.5 sec, LED 2 solid ON, LED 3 flashes 5 sec — Server comm failed, Heat Pump comm connected
On MAC-558/559 models, a rapid flash of LED 1 (0.5 seconds) with LED 2 solid ON and LED 3 flashing slowly (5 seconds) means that communication between the Wi-Fi interface and the server has failed, but communication with the Heat Pump is established.
MAC-558/559 LED 1 flashes once every 5 sec, LED 2 solid ON — WPS failed
On MAC-558/559 models, LED 1 flashing slowly once every 5 seconds while LED 2 is solid ON indicates that the WPS pairing attempt has failed.
MAC-558/559 LED 2 solid ON — Access point comm failed, Heat Pump comm starting up
On MAC-558/559 models, if only LED 2 is solid ON and LED 1 and LED 3 are off, it indicates that communication with the access point (home Wi-Fi) has failed, and communication with the Heat Pump is currently in its startup phase.
MAC-558/559 LED 2 solid ON, LED 3 flashes 5 sec — Access point comm failed, Heat Pump comm connected
On MAC-558/559 models, if LED 2 is solid ON and LED 3 flashes slowly (every 5 seconds) while LED 1 is off, it signifies that communication with the access point (your home Wi-Fi) has failed, but communication with the Heat Pump is still intact.
MAC-558/559 LED 1 flashes 5 sec, LED 2 flashes 0.5 sec — Server/AP connected, Heat Pump comm failed
On MAC-558/559 models, a slow flash of LED 1 (every 5 seconds) combined with a rapid flash of LED 2 (every 0.5 seconds) means the Wi-Fi interface is successfully connected to the server and access point, but it cannot communicate with the Heat Pump unit.
MAC-558/559 LED 1 flashes 5 sec, LED 2 solid ON — Server/AP connected, Heat Pump communication starting up
On MAC-558/559 models, LED 1 flashing slowly (every 5 seconds) with LED 2 solid ON and LED 3 OFF indicates that the Wi-Fi interface is connected to the server and access point, and communication with the Heat Pump is currently in the startup phase.
MAC-558/559 LED 1 flashes 5 sec, LED 2 solid ON, LED 3 flashes 5 sec — Server/AP/Heat Pump communication connected
On MAC-558/559 models, LED 1 flashing slowly (every 5 seconds) with LED 2 solid ON and LED 3 flashing slowly (every 5 seconds) indicates that all communications are successfully established: server, access point, and Heat Pump.
MODE light flashes once every five seconds — Interface is in Access Point (AP) pairing mode
The orange MODE light flashing once every five seconds indicates the Wi-Fi interface is in Access Point (AP) mode. In this mode, you connect your device directly to the interface's Wi-Fi network to configure it.
MODE light flashes orange once every second — Interface is in WPS pairing mode
The orange MODE light flashing once per second means the Wi-Fi interface is actively trying to connect to your router using WPS (Wi-Fi Protected Setup). This mode is used for simple, button-press pairing.
NET light not coming on — Incorrect Wi-Fi password entered
During Access Point (AP) mode setup, if you enter an incorrect Wi-Fi password for your home network in the app, the NET light on the Wi-Fi interface will not illuminate, indicating a failure to connect to the internet.
System does not control correctly or has strange behaviour — Conflicts with other controllers
If your system isn't responding as expected or exhibits unusual behavior, it could be due to conflicts between the Wi-Fi Heat Pump Control service and other local controllers or control systems.
UNIT and MODE lights temporarily on — Interface is resetting to factory settings
When you hold the reset button for up to 15 seconds, both the UNIT and MODE lights will briefly turn on. This indicates that the Wi-Fi interface is being reset to its original factory settings, clearing all stored network data.
UNIT light not flashing green by itself — Interface not in default state for pairing
Before initiating pairing, the green UNIT light should be flashing by itself, indicating the interface is in its default state. If it's not, the unit may still hold previous connection data or be in a different mode.