Repair of a Midea wall-mounted air conditioner in Sainte-Dorothée

A revealing service call: lukewarm air despite the appliance being on

At AirGreen , we were recently called to Sainte-Dorothée, Laval, to diagnose a Midea wall-mounted air conditioner that, according to the customer, was "working" but was no longer adequately cooling the room. The indoor fan was running normally, but the air outlet temperature remained lukewarm—a classic sign of a refrigeration problem.

Our technician first measured the blowing temperature using an infrared thermometer: 13.0°C was recorded. This figure, although indicating partial cooling, remained too high for a device supposed to produce air between 7°C and 9°C at medium speed.

In-depth diagnosis: low pressure and lack of refrigerant

Continuing the diagnosis, our specialists connected the digital pressure gauges to the outdoor condenser. The pressure observed was lower than normal: a clear indication of a partial lack of refrigerant . This type of anomaly is often linked to:

• a micro-leak at the flare fittings;

• a faulty crimp on the suction line;

• or, more rarely, slight porosity of the inner coil.

After inspection using an electronic detector and a foaming solution, a minimal leak was located on the solder of the condenser connection .

Intervention: clogging and complete recharging of the system

The intervention took place in three specific stages:

1. Recovery of residual refrigerant using a certified recovery station.

2. Complete brazing of the defective connection , then leak test under nitrogen at 300 psi for 30 minutes: no pressure drop was observed.

3. Recharge the system with R-410A refrigerant to the nominal charge recommended by Midea.

A final performance test then confirmed a return to normal: the blowing temperature now reached 7.4°C , a sign of a fully operational refrigeration cycle.

Result: comfort restored and efficiency restored

The customer immediately noticed the difference: significantly fresher air, quieter operation, and stabilized energy consumption. We took care to explain good maintenance practices , including:

• clean the internal filters every month;

• clear the fins of the external condenser;

• schedule an annual preventive inspection before the hot season.

At AirGreen, we emphasize prevention: a well-maintained system can easily last more than 12 to 15 years while maintaining its energy efficiency.

Our expertise serving Laval and Greater Montreal

This repair in Sainte-Dorothée perfectly illustrates our expertise in the field of residential HVAC service . We operate every day in Montreal, Laval, Longueuil, on the North Shore and the South Shore , to bring air conditioning and heat pump systems of all brands back to life: Midea, Gree, Fujitsu, Sharp, Bosch, Lennox, and many others .

Whether for a precise diagnosis , a refrigerant leak , or complete maintenance , our RBQ and CCQ certified team ensures to offer fast, durable interventions that comply with the manufacturer's standards.