A service call in the heart of Rosemont
When a resident of Montreal's Rosemont–La Petite-Patrie neighborhood contacted us, they were experiencing a common but concerning problem: their Hisense wall-mounted air conditioner was no longer blowing cold air, even though the outdoor fan was apparently working. In the early summer months, this type of failure can quickly affect indoor comfort—especially in brick homes where heat builds up.
At AirGreen , we understand that a heating, ventilation, and air conditioning (HVAC) system failure requires a quick response, accurate diagnosis, and long-term service. Our team arrived on-site the same day to inspect the unit.
Fault diagnosis: compressor inactive despite normal power supply
On site, our technician first confirmed that the Hisense wall-mounted air conditioner was indeed receiving power. The operating indicator light was on, and the condenser fan was running. However, no cold was being produced inside.
A quick pressure check revealed abnormally low static pressure , indicating a possible refrigerant leak . After testing the fittings and flanges with an electronic detector, the leak was located at the service connection of the outdoor compressor .
Complete repair and return to service
Step 1: Drain and Braze
We proceeded to completely recover the refrigerant before re-brazing the faulty connection . Once the connection was re-made, a nitrogen pressure test was carried out to ensure the circuit was leak-proof.
Step 2: Vacuum and refill
After a successful vacuum test at 500 microns , we recharged the system with R410A , according to Hisense specifications. The pressure and temperature values were monitored until an optimal temperature difference between the inlet and outlet of the indoor unit was obtained.
Step 3: Check drainage and communication
Finally, a complete test of the condensate drainage and communication between the electronic boards confirmed that the device was working as expected again.
Result: restored comfort and optimized performance
In less than two hours, the customer was back to ideal thermal comfort . His Hisense wall-mounted air conditioner displayed a blowing temperature of 12°C , which meets the performance standards for a residential wall-mounted unit.
Our technician also installed a discreet wall cable protector to improve the durability and aesthetics of the installation, in accordance with HVAC standards.
AirGreen Tips to Avoid Future Outages
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Mandatory annual maintenance : cleaning and inspection before each hot season helps prevent leaks and loss of performance.
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Pressure Check : Slow loss of refrigerant can be detected in advance by a technician.
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Protect the joints : temperature variations and vibrations can weaken the soldering, especially on brick walls exposed to the sun.
At AirGreen , we emphasize the importance of prevention . Annual maintenance, carried out by our teams in Montreal, Laval, Longueuil, the North Shore and the South Shore, ensures the longevity of your HVAC systems.
AirGreen expertise at your service
With our experience on brands like Hisense, Gree, Fujitsu, Sharp, Midea and Daikin , we efficiently work on all types of heat pumps and wall-mounted air conditioners . Every service call is an opportunity to restore not only the comfort, but also the energy reliability of your system.
AirGreen is a reliable, fast HVAC repair service that meets the highest standards in Quebec.
Our interventions cover the entire Greater Montreal area, including Rosemont, Laval, Longueuil, Brossard, and the North Shore .
Warning:
Handling involving refrigeration circuits and brazing must only be carried out by certified technicians holding a refrigeration certificate (class C or D) recognized by the Régie du bâtiment du Québec (RBQ) .
Any unprofessional intervention may result in loss of warranty or safety risks.