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

A service call for comfort restored in the heart of Laval

At AirGreen , we know how essential a high-performance wall-mounted air conditioner is to maintaining consistent comfort, especially on the hot days of Laval's summer. Recently, our team intervened in Sainte-Dorothée , a peaceful residential area of ​​Laval , to diagnose and repair a Midea wall-mounted air conditioner that was no longer cooling efficiently.

The context of the intervention

The customer contacted us after noticing that their Midea HVAC system was blowing lukewarm air despite being set to a low temperature. This common symptom often masks a more complex problem than simply missing maintenance. When we arrived, the indoor unit was displaying a flashing light indicating a communication anomaly between the indoor and outdoor units .

Detailed diagnosis

Our certified technicians carried out a complete diagnosis, including:

• Checking the communication wiring between units;

• Measurement of electrical voltages on the main board;

• Inspection of the evaporator coil and air filters;

• Analysis of the refrigeration cycle using a digital pressure gauge.

The diagnosis revealed two problems:

1. A slightly oxidized connection on the communications terminal, causing intermittent signal loss;

2. An indoor unit electronic board exhibiting random startup, typical of premature wear.

The AirGreen solution

After disconnecting the unit and securing the circuit, our team:

• Cleaned and tightened electrical connections ;

• Replaced the electronic control board with an original Midea part;

• Checked the correct operation of the ambient temperature sensor ;

• Performed a full restart test to ensure proper heat exchange.

Once the system was restarted, the heat pump returned to optimal operation: constant cold air, regular flow, and no abnormal noise .

Technical details of the system

• Brand : Midea

• Type : Wall-mounted air conditioner (mini-split)

• Estimated power : 12,000 BTU

• Original installation : approximately 4 years

• Problems observed : no cooling, error lights, slight noise at startup

• Parts replaced : internal electronic board

Advice given to the client

Before we left, we took the time to remind you of some good maintenance practices :

• Clean air filters every 3 to 4 weeks during periods of heavy use;

• Check that nothing is obstructing the outdoor unit (leaves, dust, etc.);

• Avoid turning off the power to the system between seasons;

• Schedule an annual preventive inspection to maximize the life of the heat pump.

Final result

The Sainte-Dorothée client regained optimal comfort in his living room in less than two hours of work. The indoor temperature was stabilized again, and the system's energy efficiency was restored.

At AirGreen, every service call is an opportunity to demonstrate our HVAC expertise , our technical rigor , and our commitment to the total satisfaction of our customers, whether in Montreal, Laval, Longueuil, on the North Shore or the South Shore .