Repair of a Midea wall-mounted heat pump in Sainte-Dorothée

An urgent service call on a green roof

On a flat roof of a building in Sainte-Dorothée , Laval, our team was recently called for an urgent HVAC intervention . Two Midea wall-mounted heat pump outdoor units had completely shut down. These systems, essential to the comfort of the occupants, showed obvious signs of neglect: invasive vegetation, abundant moss on the roof, and wiring exposed to the elements.

At AirGreen , we know that proper maintenance is as crucial as a unit's performance. This call allowed us to bring two abandoned heat pumps back to life.

Complete diagnosis: when the environment harms performance

Upon arrival, we carried out a complete inspection of the two outdoor capacitors. Several critical points were immediately noted:

• Accumulation of organic debris (leaves, moss, maple seeds) around and under the units, obstructing drainage.

• Deteriorated refrigeration line insulation , exposing pipes to heat and humidity.

• Poorly protected electrical cables , risking water infiltration or a short circuit.

• Rotting wood support , compromising stability and ventilation under appliances.

We also noticed that the Midea units were installed too close together, restricting airflow—a common cause of compressor overheating.

Repair and compliance steps

Our certified technicians have proceeded rigorously:

1. Complete area cleanup : removal of moss, leaves and debris to restore a clear surface around the units.

2. Drainage restoration : clearing blocked roof drain, preventing water from accumulating under condensers.

3. Refrigeration circuit check : Nitrogen pressure test to ensure no refrigerant leaks were present.

4. Insulation repair : replacement of damaged insulation sheath sections with new UV-resistant sleeves.

5. Securing wiring : repositioning and securing electrical conduits with corrosion-resistant fasteners.

6. Repositioning on new supports : installation of anti-vibration polymer bases, ensuring better ventilation and durability.

7. Cleaning the exchangers : application of a biodegradable cleaner to restore the thermal efficiency of the coils.

Finally, a complete operating test confirmed pressure stability, thermodynamic cycle recovery and a noise level in line with Midea standards.

Result: restored performance, guaranteed comfort

Once the repair was complete, the two Midea wall-mounted heat pumps returned to optimal operation. The occupants immediately felt the difference: consistent cooling throughout the building and a noticeable reduction in outside noise .

Thanks to this intervention, the systems are now:

• More energy efficient ;

• Better protected against bad weather ;

• Easy to maintain for years to come .

AirGreen Lessons and Recommendations

This type of intervention is a reminder of the importance of regular preventative maintenance . Even a high-performance heat pump like the Midea can suffer from reduced efficiency or premature breakdowns if it is exposed to:

• recurring plant debris ;

• poor cold insulation ;

• poor positioning on the roof;

• a lack of air clearance .

At AirGreen , we recommend:

• A complete inspection in spring and fall ;

• Condenser cleaning after pollination periods;

• A check of the refrigerant level and vacuum every two years;

• And, if possible, installation on raised supports with at least 12 inches of clearance around the units.

Why choose AirGreen?

We operate throughout Montreal, Laval, Longueuil, the North Shore and the South Shore , with qualified technicians to diagnose and repair all types of HVAC systems , whether Midea, Fujitsu, Gree, Zephyr, or Mitsubishi .

Every repair is performed according to manufacturer standards and municipal regulations , ensuring safety, performance and peace of mind.

Thanks to our expertise, customers know their heat pumps are in good hands —and that their comfort is always our priority.