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Réparation d’une thermopompe murale Gree à Rosemère
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Repair of a Gree wall-mounted heat pump in Rosemère

When a power outage becomes an opportunity for energy optimization

At AirGreen , every HVAC intervention is an opportunity to ensure our customers lasting comfort and maximum performance .
Our team was recently called to Rosemère , on the North Shore of Montreal , for a Gree wall-mounted heat pump that had suddenly stopped working after a violent storm.

Concerned about the lack of heat on a chilly June morning, the customer contacted us through our emergency service. Less than 24 hours later, our technicians were on site to diagnose the problem.

Initial diagnosis: an inert outdoor unit

Upon arrival, we observed that the Gree outdoor unit was no longer responding at all to the indoor wall control.
No compressor noise, no fan movement — complete silence .

Our initial checks revealed:

  • Power supply interrupted at the disconnect box.

  • Damaged thermal fuse inside the outdoor unit.

  • Slightly blackened electronic card , sign of a short circuit due to an overvoltage.

Thunderstorms can cause voltage spikes that damage electronic components, particularly on modern wall-mounted heat pumps with variable frequency drives (inverters) .

Step 1: Electrical and Safety Testing

Before any manipulation, we have:

  1. Cut off the main power supply to make the intervention safe.

  2. Tested the circuit for continuity using a multimeter.

  3. Checked that the grounding was correct (a point often overlooked, but crucial for the safety and durability of electronic boards).

These measurements confirmed that the problem was indeed with the power board , and not with the compressor or the fan motor.

Step 2: Replacing the electronic card

We ordered an original Gree power supply board , perfectly compatible with the customer's model.
Upon receipt, the AirGreen team returned to:

  • Complete removal of the damaged card ,

  • Cleaning electrical connections ,

  • And installing the new card , making sure all polarities and connectors were correctly aligned.

A high-voltage fuse was also replaced, and an additional surge protector was installed at the outdoor circuit breaker—a recommended preventative measure in areas prone to frequent thunderstorms.

Step 3: Complete cycle check

Once the board was replaced, we powered the system back up and observed the compressor gradually starting up :

  • Fan running smoothly , without abnormal noise,

  • Refrigerant pressures in accordance with the technical data sheet,

  • Hot air returned to the interior in less than 90 seconds.

We then let the system run for 20 minutes to confirm the stability of the heating and cooling cycle.

Result: no fluctuations , no errors on the control panel , and efficiency restored to 100% .

Step 4: Preventive maintenance and advice

Beyond the repair, our technicians carried out a complete maintenance of the outdoor unit :

  • Cleaning the condenser and fan ,

  • Tightening of all electrical connections,

  • Checking the thermistor wiring ,

  • And application of a dielectric protector on the connection terminals.

We also advised the customer to install a voltage regulator or surge protector , to prevent this type of incident from happening again.

Final result: comfort and reliability restored

A few hours after our visit, the customer called us back to confirm that his Gree heat pump was working perfectly and that he had regained stable thermal comfort throughout the house.

Thanks to this intervention, the system is not only working again, but it is now better protected against electrical fluctuations and ready to face hot summers as well as harsh winters.

The AirGreen commitment: expertise, precision and prevention

At AirGreen , we do more than repair: we analyze, correct and prevent.
Every detail counts—from power supply voltage to cable placement—to extend the life of your HVAC unit .

Our technicians are trained on all major brands, including Gree, Fujitsu, Midea, Zephyr, Trane and Sharp , and respond quickly in Montreal, Laval, Longueuil, on the North Shore and the South Shore .

Because your comfort deserves expert attention, AirGreen remains the benchmark in repair and maintenance of wall-mounted heat pumps in Quebec .

Technical summary of the intervention:

  • Device type: Wall-mounted heat pump

  • Brand: Gree

  • Location: Rosemère (North Shore)

  • Problem: Total failure due to power surge

  • Solution: Replacement of the electronic card and thermal fuse, addition of lightning protection

  • Result: System restored, optimal performance, improved protection