Midea wall-mounted air conditioner repair in Ville Saint-Laurent

Refrigerant leak causing loss of performance

At AirGreen , every service call is an opportunity to demonstrate our HVAC expertise through rigorous diagnosis and lasting repairs. That day, we were called to Ville Saint-Laurent , in a quiet residential neighborhood, for a Midea wall-mounted air conditioner whose performance had dropped considerably.

Symptoms reported by the client

The customer contacted us after noticing that his wall-mounted air conditioner was no longer cooling properly , even at full power. The airflow was constant, but the expelled air remained lukewarm , and the compressor seemed to be running longer than usual.
On site, we quickly noticed an accumulation of oil and residue near the passage of the refrigerant lines - a typical indication of a refrigerant leak .

Inspection and diagnosis

Our technicians have begun a complete inspection of the refrigeration circuit :

1. Visual inspection : the connection between the suction line and the wall showed slight oxidation and oily traces .

2. Nitrogen pressure test : a gradual drop in pressure confirmed a microleak at the flare connection .

3. Compressor and condenser check : No mechanical damage, Midea compressor responded normally to cooling demand.

The diagnosis was therefore clear: R-410A refrigerant leak caused by a poorly sealed connection , probably due to thermal expansion and aging of the seal.

Intervention and repair

We undertook a complete repair, step by step:

• Step 1: Purging the circuit and recovering residual refrigerant in accordance with environmental standards.

• Step 2: Replace the flare fitting and clean the suction line using a specialized solvent.

• Step 3: Application of a high-pressure polymer-based seal to enhance vibration resistance.

• Step 4: Recharge the system with new R-410A , weigh precisely on an electronic scale.

• Step 5: Check the condensate flow rate and adjust the drainage line (visible in the photo, now securely fixed).

After recharging, the air conditioner returned to its optimal performance : cold air, stable pressure, and quiet operation.

Final result

The customer immediately noticed a difference. Within minutes, the interior temperature dropped back to 22°C , and the compressor resumed its normal modulation cycle .
The outdoor unit, securely fixed to the plastered wall, no longer showed any visible leaks.

Thanks to a careful and lasting repair , the Midea heat pump (residential R-410A range) was able to be put back into service without a complete replacement — a considerable gain in comfort and savings for the owner.

AirGreen Prevention and Advice

We took advantage of this visit to explain some good maintenance practices to the customer:

• Have refrigeration connections checked every two years to prevent micro-leaks.

• Monitor for oil or corrosion near wall outlets.

• Clean the internal filters every month during the summer season.

• Ensure that the condensate drain remains clear to prevent water from flowing back.

At AirGreen, we always emphasize the importance of regular preventative maintenance , which extends the life of the system and optimizes its energy efficiency.

AirGreen: your trusted partner in Montreal and its surrounding areas

Our specialized teams operate every day in Montreal , Laval , Longueuil , on the North Shore and the South Shore , to offer fast, transparent and lasting repairs on all brands of air conditioners and heat pumps: Midea, Gree, Sharp, Fujitsu, Bosch, Goodman, Zephyr , and many others.

Our mission: to ensure your comfort in all seasons thanks to interventions carried out according to the highest standards of the HVAC profession in Quebec.

AirGreen – The local, reliable and professional HVAC service in Montreal, Laval, Longueuil, North Shore and South Shore.