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

A delicate technical intervention on a narrow balcony

When a Midea heating and cooling system breaks down in the middle of a Montreal winter, every minute counts. At AirGreen , we're regularly called upon to intervene in complex situations where access is limited—like this specific case in Outremont , a residential neighborhood where wall-mounted systems are often located on narrow balconies or under wooden structures.
Our mission: to diagnose and repair a Midea wall-mounted heat pump that refused to start, despite several attempts by the customer to restart it.

Context of the call and initial findings

The customer noticed that his heat pump was no longer blowing hot air, even in heating mode, even though the indoor unit was operating normally. There was no noise coming from the outdoor compressor.
Upon arrival, our certified technicians noted that:

  • The outdoor unit, located under a wooden balcony, was exposed to extreme cold and difficult to access .

  • The refrigerant lines and electrical cables appeared fine at first glance.

  • The current reached the electronic card , but no signal was transmitted to the compressor.

These clues suggested an electrical or communication problem between the units .

In-depth diagnosis with instrumentation

To confirm our hypotheses, our technician carried out several checks using precision instruments:

  1. Test the continuity of the cables between the indoor and outdoor unit.

  2. Measuring the supply voltage on the main board.

  3. Analysis of the outside temperature sensor (a sensor often responsible for a refusal to start).

  4. Checking R-410A refrigerant pressure using an electronic manifold.

The measurements quickly confirmed a double problem:

  • A damaged control board (no signal to the compressor relay).

  • Insufficient refrigerant charge , probably due to a slow leak.

Complete repair and recommissioning

We carried out a complete replacement of the electronic board of the outdoor unit with an original Midea model, then carried out a recharge of R-410A refrigerant calibrated according to the manufacturer's specifications.

Each step was carried out with rigor:

  • Vacuum the circuit for 30 minutes to eliminate all traces of humidity.

  • Accurate weighing of refrigerant using a certified digital scale.

  • Soft start test with measurement of compressor current and blowing temperature.

Once the repair was complete, the heat pump restarted without any problems. The indoor blowing temperature rose to 42°C in less than 3 minutes—proof of optimal thermal efficiency .

Safety and working at height: rigor above all

This intervention presented a particular challenge: the outdoor unit was installed more than 3 meters above the ground , fixed under a balcony structure.
Our technicians therefore used:

  • A secure platform and reinforced wooden supports to stabilize the workspace.

  • Insulating gloves and a voltage detector to ensure electrical safety.

  • A nitrogen leak test before refrigerant recharge, to eliminate any micro-leaks.

These precautions are essential to avoid any incident and ensure the durability of the system.

Results: comfort regained and efficiency restored

At the end of the intervention:

  • The Midea system displayed balanced and stable pressure.

  • The new control board ensured smooth communication between the units.

  • The customer was able to enjoy constant heating, even at -15°C outside.

We also took the time to explain some simple preventive measures to him:

  • Keep the area around the outdoor unit clear.

  • Check regularly for frost.

  • Schedule annual maintenance before the cold season to avoid unplanned downtime.

Why trust AirGreen for your Midea repairs

At AirGreen , our expertise is based on over a decade of experience in HVAC repair and installation in the greater Montreal area.
Our strengths:

  • Certified and trained technicians on Midea, Gree, Fujitsu, Sharp, and other brands.

  • Fast service in all neighborhoods: Outremont, Côte-des-Neiges, Rosemont, Laval, Longueuil, North Shore and South Shore.

  • Accurate diagnosis thanks to professional tools (digital manifold, electronic testers, leak detectors).

  • Complete transparency on replaced parts and costs.

Each intervention has a single objective: to restore customer comfort while extending the life of the system .

A heat pump ready for several winters

After a few hours of meticulous work, this Midea heat pump is now ready to face the rigors of Montreal's winter.
Thanks to a new card , a calibrated refrigerant charge and complete maintenance , the appliance once again offers optimal energy efficiency and constant comfort throughout the house.