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Réparation d’une thermopompe murale Hisense à Côte-des-Neiges–Notre-Dame-de-Grâce
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Repair of a Hisense wall-mounted heat pump in Côte-des-Neiges–Notre-Dame-de-Grâce

AirGreen intervention on a residential roof in Montreal

Recently, our AirGreen team was called to repair a Hisense wall-mounted heat pump on the roof of a residential building in the Côte-des-Neiges–Notre-Dame-de-Grâce sector of Montreal.
The client, a condo owner, noticed that his system was no longer producing hot air, while the neighboring Gree heat pump was operating normally. This situation suggested a specific problem with the Hisense Inverter unit, often used for compact urban-type installations.

Diagnosis: Loss of performance and compressor failure

On site, our technician noticed that the Hisense Inverter heat pump was installed on a roof slab, surrounded by wooden railings and other outdoor units. Access was restricted, but our team is accustomed to working in complex urban environments, where every inch counts.

Diagnostic steps:

  1. Power supply check : Input voltage was correct, ruling out a circuit breaker failure.

  2. Communication test between units : the control signals arrived correctly at the outdoor unit.

  3. Observation of the start cycle : the fan started, but the compressor remained inactive .

  4. Compressor resistance measurement : abnormal values ​​indicating a partially burnt winding .

  5. Inspection of the refrigeration circuit : no apparent leaks, but slight overheating observed at start-up.

This diagnosis confirmed a failure of the Inverter compressor , caused by a prolonged power surge during the previous winter.

Repair: Compressor replacement and system optimization

Replacing the compressor on a Hisense Inverter unit requires precision and adherence to manufacturer protocols.
Our team proceeded to:

  1. Complete recovery of R-410A refrigerant , to avoid any unnecessary loss or discharge.

  2. Dismantling the faulty compressor , carefully insulating the electrical and refrigeration connections.

  3. Installation of the new original Hisense compressor , delivered and certified by our distributor partner.

  4. Complete vacuuming of the circuit to eliminate all traces of humidity.

  5. Recharging the system with the exact amount of refrigerant recommended by the manufacturer.

  6. The final pressure and energy efficiency test.

Once the installation was completed, the heat pump returned to stable, quiet and efficient operation, with optimal heating output and smooth compressor start-up .

Technical details and observations

Site Conditions:

  • Flat concrete roof covered with a membrane.

  • Restricted access due to the wooden railing.

  • Presence of several units side by side: Hisense , Gree , and another unit of unidentified brand.

Equipment type:

  • Hisense Inverter 12000 BTU wall-mounted heat pump .

  • Refrigerant: R-410A .

  • Power supply: 240 V single phase .

Special features of the intervention:

  • Moisture and salt accumulated over the winter had slightly oxidized the unit's connections.

  • Poor air circulation around the condenser, due to the confined space, likely contributed to the compressor overheating.

AirGreen Recommendations for Rooftop Installations

Rooftop installations, common in the central boroughs of Montreal, require special attention:

  1. Ensure a minimum clearance of 30 cm around each unit , to allow good airflow.

  2. Avoid overheated surfaces , such as black membrane roofs exposed to the sun.

  3. Inspect cables and conduits after each winter , as frost and UV rays can damage the insulation.

  4. Have refrigerant pressures checked at least once a year to prevent overheating.

  5. Protect units with a light shelter or windscreen to reduce direct exposure.

These simple actions can significantly extend the lifespan of Hisense, Gree, Fujitsu, Sharp and other similar wall-mounted heat pumps .

Final result: comfort restored and customer reassured

After the repair, the customer was immediately able to see that their HVAC system was fully operational again .
The heating and air conditioning responded perfectly, and the electricity consumption stabilized thanks to the new inverter regulation.
Our technicians took the time to explain how the variable-speed compressor works and the warning signs of a future problem—a transparent and educational service, typical of our AirGreen approach.

AirGreen expertise in the heart of Montreal

This intervention in the Côte-des-Neiges–Notre-Dame-de-Grâce district demonstrates our versatility: whether it is a repair on a roof, duplex or condo, our technicians are trained to quickly diagnose and intervene effectively on all brands of wall-mounted heat pumps , including Hisense, Gree, Midea, Fujitsu and Sharp .

Every service call is an opportunity for us to restore residents' comfort , while ensuring the durability and energy performance of their HVAC systems.

AirGreen – HVAC repair experts in Montreal, Laval, North Shore and South Shore.
Reliability, transparency and technical excellence – your comfort is our priority.