An electrical problem hidden behind a sudden outage
At AirGreen , we work daily on wall-mounted heat pump systems across Greater Montreal. Recently, our team was called out for a complete breakdown of a Gree unit installed in a residence in Sainte-Dorothée (Laval) . The customer reported that the unit had stopped working overnight, with no error message on the screen and no response to the remote control. A typical case where accurate diagnosis makes all the difference.
On-site diagnosis: internal power outage
Upon arrival, we noticed that the wall unit seemed completely inert. After checking the supply voltage at the heat pump input, we confirmed that the current was indeed reaching the main terminal block. The problem therefore originated from inside the unit itself .
Upon opening the front panel, our technician immediately spotted several clues:
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Exposed and unconnected wires , suggesting a break in the internal power circuit.
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A slightly oxidized slice of wiring , possibly due to condensation accumulated over time.
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No visible damage to the control board, which pointed the cause to a faulty connection or broken wire .
Thorough inspection of the ventilation module
To confirm the diagnosis, we partially disassembled the indoor unit. Once the rear cover was removed, the electrical components of the fan motor and control board were exposed. We noticed that the main red wire connecting the board to the motor was broken —a sneaky failure often caused by the constant vibration of the unit and the natural wear of the copper inside the sheath.
We have :
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Cut and resoldered damaged wires according to HVAC standards.
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Replaced the cable section with a wire of the same gauge, heat-shrink sheathed to prevent any future oxidation.
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Checked the integrity of the ground connections and neutral terminals , often neglected but essential to the electrical stability of the unit.
Cleaning and security testing
Before closing the case, we took advantage of the full access to the unit to perform:
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Cleaning the evaporator coil with a biodegradable product.
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A check of the tangential fan , sometimes slowed down by the accumulation of dust.
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An inspection of the temperature sensor welds , which remained intact.
Once everything was reassembled, we restored the power and tested the system under several cycles: heating, cooling and dehumidification.
Result: immediate restart , stable air circulation and perfectly silent operation.
Result: comfort restored and safety assured
The customer regained full operation of his Gree heat pump, with powerful airflow and perfectly regulated temperature.
We recommended to him:
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Have the electrical connections inspected once a year , especially for appliances over 5 years old.
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Clean the filters every two months during the heating and cooling season.
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Avoid handling power cables, even for dusting purposes — a trivial action that can lead to a similar cut.
Why entrust your repairs to AirGreen?
Our expertise in residential HVAC systems allows us to work on all recognized brands — Midea, Fujitsu, Gree, Sharp, Goodman, Zephyr, Lennox , and many others — with the same rigor and precision.
Each intervention is preceded by a complete diagnosis , including:
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Electrical and electronic verification,
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Preventive cleaning,
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Performance testing and calibration.
Our certified technicians travel throughout Laval, Montreal, Longueuil, the North Shore and the South Shore , offering fast, professional and transparent service.
A lasting repair and a satisfied customer
This repair, although seemingly minor, perfectly illustrates the importance of in-depth expertise and meticulous work . A simple cut wire could have led to an unnecessary replacement of the electronic board or, worse, the entire unit. Thanks to a targeted intervention, we avoided significant costs and extended the life of the heat pump by several years.
AirGreen: smart maintenance of your HVAC systems
At AirGreen, we believe that regular maintenance and prompt intervention are the key to consistent comfort.
Whether it's a wiring problem, a refrigerant leak, an engine failure or an electronic board issue, our technicians intervene with precision and transparency to restore the performance of your system, wherever you are in Greater Montreal.