Home » Some of Our Service Calls in Greater Montreal » Gree wall-mounted air conditioner repair in Ville Mont-Royal
Réparation d’un climatiseur mural Gree à Ville Mont-Royal
Reading time: 4'

Gree wall-mounted air conditioner repair in Ville Mont-Royal

An unexpected breakdown in a well-insulated condo

It was in a modern apartment in Ville Mont-Royal , in the heart of the island of Montreal, that our AirGreen team was called to diagnose a Gree wall-mounted air conditioner that refused to start despite several attempts by the owner. In the middle of summer, the lack of air conditioning made the days difficult, especially since the apartment, well insulated and facing south, stored the heat.

The model in question—a Gree Lomo 12,000 BTU —was installed above a closet, a common configuration in apartments and condos where wall space is limited. This type of installation, while discreet, presents some unique challenges in terms of maintenance and ventilation.

Diagnosis: faulty electronic board and temperature sensor

During our initial inspection, our technicians noticed that:

  • The indoor unit would turn on briefly before turning off.

  • The display showed an error code E6 , typical of a communication problem between the indoor and outdoor unit.

  • The indoor fan was running intermittently, a sign of an unstable control board.

After performing a series of electrical and continuity tests, the diagnosis was confirmed:

  • The main circuit board was damaged, probably due to a power surge.

  • The ambient temperature sensor (thermistor) was giving inconsistent values, preventing the unit from adjusting the temperature correctly.

This combination of anomalies perfectly explained the unscheduled stops and the lack of cold felt by the customer.

Intervention: card replacement and sensor calibration

At AirGreen, every repair is performed according to manufacturer standards, using genuine parts to ensure durability and performance. In this case, we have:

  1. Replaced the original Gree control board , installed in the upper compartment of the wall unit.

  2. Replaced the temperature sensor with a factory-calibrated model, ensuring accurate reading and better regulation.

  3. Cleaned the evaporator coil and fan impeller, which often get clogged when the unit is installed above a cupboard (dust buildup).

  4. Checked communication between units via the 4-wire cable, ensuring perfect continuity and proper tightening of the connectors.

  5. Performed a comprehensive performance test , including measurement of blowing temperature, fan speed and ambient temperature stability after 15 minutes of operation.

At the end of the intervention, the air conditioner was working again with a stable blowing temperature of 8°C, a performance in line with factory specifications for this type of device.

Special features of this wall installation

High wall installations , often located above doors or cupboards, require special attention:

  • Air circulation may be obstructed by clothing or objects stored nearby.

  • The unit is often exposed to higher ambient heat , which increases the compressor load.

  • Access for filter cleaning is sometimes neglected, reducing energy performance by 10 to 20%.

Our technicians took the time to explain some good maintenance practices to the customer:

  • Clean air filters every 4 to 6 weeks.

  • Leave at least 50 cm of clearance under the unit.

  • Schedule annual preventive maintenance , ideally in spring, before the first warm weather.

AirGreen expertise: precision and transparency

At AirGreen , we understand that every breakdown is unique. That's why our teams follow a rigorous protocol:

  • Complete diagnosis before any repair.

  • Exclusive use of Gree certified parts .

  • Performance testing and delivery of detailed report to the client.

Our goal: to restore indoor comfort while extending the life of your HVAC systems . Thanks to our services, many homeowners in Montreal, Laval, Longueuil, as well as municipalities on the North and South Shores, avoid costly replacements by benefiting from professional, fast, and honest repair service.

Result: restored comfort and improved performance

The customer immediately noticed the return of stable and quiet cooling , without untimely restarts. The Gree wall-mounted air conditioner is now operating at full efficiency, reducing the indoor temperature from 27°C to 22°C in less than 20 minutes.

This type of intervention perfectly illustrates our philosophy: to intervene with precision, transparency and respect for the comfort of the occupants.

At AirGreen, we do more than repair: we bring your air conditioning systems back to life.