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Appel de service pour un climatiseur mural Midea à Rosemont–La Petite-Patrie
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Service call for a Midea wall-mounted air conditioner in Rosemont–La Petite-Patrie

Rapid intervention to restore comfort to a Montreal building

At AirGreen , we frequently receive calls from older rental buildings in Montreal, where wall-mounted air conditioning systems have been installed over the years on various balconies. This is exactly the case during this service call in Rosemont–La Petite-Patrie , in a typical brick building with an exterior spiral staircase and several Midea units visible on the rear facade.

One of the occupants of the second floor contacted us after noticing that his Midea wall-mounted air conditioner was blowing lukewarm air, even at full power. With the return of summer heat, the temperature in his apartment was rising rapidly, making daily life uncomfortable.

Complete diagnosis: a lack of refrigerant is the cause of the problem

Our technician quickly arrived on site. Upon arrival, several clues caught our attention:

  • The outdoor compressor would start and then stop after a few seconds.

  • The refrigeration piping showed no visible condensation.

  • There was a slight trace of oil present at the base of the fitting on the fluid line.

These signs pointed to a refrigerant leak —a common problem in wall-mounted installations exposed to temperature fluctuations and structural vibrations.

To confirm this hypothesis, our team carried out:

  • A 300 psi nitrogen leak test to detect microleaks.

  • A careful visual inspection using an electronic detector.

  • A check of the condensation drain , often blocked on old balconies.

Result: a leak was identified on the flare connection of the suction pipe, which was slightly loose and oxidized over time.

Midea System Repair and Recommissioning

Once the diagnosis was confirmed, our technician undertook the complete repair:

  1. Replacing the flare and cleaning the connection .

  2. Reinforcement welding to ensure lasting waterproofing.

  3. New vacuum draw of the circuit to eliminate any humidity.

  4. Complete recharge with R-410A refrigerant , following Midea manufacturer specifications.

  5. Checking operating pressures and temperatures .

  6. Cleaning the outer coil and inner filter .

When it was turned back on, the air conditioner quickly returned to normal performance:

  • Stable suction pressure at 118 psi.

  • Blowing temperature at 11°C.

  • Noise level meets Midea standards.

The customer immediately felt the difference: constant and uniform freshness throughout the accommodation, without temperature variations.

Safety and preventive maintenance in multi-story buildings

Wall installations in multi-unit buildings have specific features: difficult access to balconies, working height, collective cabling, etc.
At AirGreen, we follow strict protocols for each intervention:

  • Securing access with harnesses and anchoring tools.

  • Use of ladders adapted to Montreal's narrow facades.

  • Protection of equipment and surfaces of neighboring co-owners.

We always recommend that building managers and tenants:

  • Have their Midea units inspected at least once a year.

  • Clean the internal filters every two months during the summer season.

  • Check the clearance around the outdoor condenser (no objects or foliage should block the air).

These simple actions extend the life of the system and prevent the majority of summer breakdowns.

Result: restored comfort and optimized performance

The intervention was completed the same day.
Thanks to a quick and precise repair , the tenant was able to enjoy optimal comfort again without expensive replacement.
The building owner, impressed by the quality of service, asked us to perform preventative maintenance on the other four Midea units in the building before the next heat wave.

At AirGreen , we view every service call as an opportunity to extend the useful life of HVAC systems while improving the energy performance of Montreal buildings.

AirGreen: your HVAC partner in Montreal, Laval, Longueuil, North Shore and South Shore

Whether it's a Midea wall-mounted air conditioner , a multi-zone heat pump , or a central system , our team responds with rigor and expertise. We offer diagnostic, repair, and maintenance services throughout Greater Montreal—from Rosemont to Laval, from Brossard to Terrebonne.

Call AirGreen for all your HVAC repair needs: we ensure reliable comfort, no matter how complex the installation.