An urgent service call for a broken appliance in the middle of winter
At AirGreen , we often receive calls about breakdowns of wall-mounted air conditioners that also serve as heat pumps in heating mode. This is the case of this customer located in Outremont , who contacted us after his Gree wall-mounted unit stopped blowing hot air. The diagnosis was complex, especially since the unit was installed above a door, making access difficult and handling tricky.
Initial diagnosis: loss of power and electronic card fault
Upon arrival, we first noticed that the Gree wall-mounted air conditioner did not respond to any commands, either from the remote control or via the manual button on the panel.
Our checks revealed:
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Correct supply voltage reaching the indoor unit.
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No communication signal detected between the indoor unit and the outdoor compressor.
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Disconnected and partially torn wires from the control terminal block, probably due to previous mishandling.
The device also displayed an error code E6 , typical of a communication problem between electronic cards .
Step 1: Access and Safe Disassembly of the Wall Unit
With the unit installed nearly 2.5 meters high, just above a doorframe, we used secure telescopic brackets to hold the air conditioner in place during disassembly. This step is crucial to avoid any stress on the wall plate or refrigerant lines.
Once the hood was open, we accessed the main control board and the communications terminal block . Several wires showed signs of oxidation and weakened connections.
Step 2: Repair the connections and replace the control board
We have proceeded to:
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Complete replacement of the main electronic board (compatible model Gree Lomo series 12,000 BTU).
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Reconnecting the power and communication wiring , respecting the Gree color code (1–2–3 + ground).
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Mechanical tightening of the connectors and application of an insulating varnish to protect the tracks against humidity.
After this step, the unit came back to life immediately: the operating indicator light came on and the fan motor restarted.
Step 3: Checking operation in heating mode
To confirm the repair, we performed a complete test in heat pump mode :
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Stable suction pressure at 125 psi.
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Blown air temperature at 41°C after 5 minutes .
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Stable communication between the two cards (no error codes).
The customer was able to observe the rapid rise in ambient temperature , confirming that the compressor and the refrigeration cycle were operating normally.
Step 4: Cleaning and Prevention
Before closing the hood, we took advantage of the intervention to:
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Clean the evaporator fins .
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Vacuum the dust deposits in the condensate collection tray.
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Check drainage to prevent water leakage during future defrost cycles.
We also replaced the covers and checked that the wall fixings were free of any play, ensuring the long-term safety of the installation.
Result: comfort restored and reliability restored
At the end of the intervention, the Gree wall-mounted air conditioner was working perfectly. The customer was able to benefit from stable, quiet and efficient heating , just in time for a freezing winter evening.
Thanks to the refurbishment of the electronic circuit , the device is now ready to provide several seasons without worry.
AirGreen Tips for Your Wall-Mounted Air Conditioners
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Avoid unprofessional tampering with wiring: terminal blocks are sensitive and can cause costly communication errors.
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Have your unit inspected at least once a year, even if it appears to be operating normally.
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Clean the filter and fins every three months to maximize performance.
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If in doubt, call a certified technician for any work on the electronic card or the refrigeration circuit.
AirGreen: your HVAC specialist in Outremont and throughout Greater Montreal
At AirGreen , we work daily on wall-mounted air conditioners and heat pumps from Gree, Fujitsu, Sharp, Midea, Zephyr, and many others .
Our teams cover Montreal, Laval, Longueuil, the North Shore and the South Shore , always with the same commitment: precise, transparent and sustainable service .
Every repair is an opportunity for us to extend the life of your device and guarantee you optimal comfort, whatever the season.