Repair of a Gree wall-mounted air conditioner in Rosemont–La Petite-Patrie

A service call in a typical Montreal backyard

At AirGreen , we work every day in a wide variety of residential settings: duplexes, triplexes, condominiums, single-family homes, etc. Our mission remains the same: to ensure the performance and reliability of our clients' HVAC systems across Greater Montreal.
This time, our team traveled to the Rosemont–La Petite-Patrie neighborhood to repair a Gree wall-mounted air conditioner installed on a brick facade overlooking a typical backyard in the Plateau and Rosemont areas.

Initial observation: an air conditioner that no longer cooled

The customer had noticed that, despite a normal display on the remote control, the air blown inside was lukewarm . The outdoor unit—a 12,000 BTU wall-mounted Gree —was intermittently starting, without the compressor systematically starting. No unusual noise, but a total lack of cooling efficiency .

Visual clues pointed us towards a refrigeration circuit or control problem:

• Operation indicator light on, but no pressure variation in the lines.

• Condensation present at the drain connection, a sign that the interior fan was working.

• No error code visible on the indoor unit.

AirGreen Diagnosis: A faulty control board

Our technicians carried out a complete diagnosis of the HVAC system :

1. Electrical continuity test between main board and compressor → inconsistent reading on two phases.

2. Starting capacitor measurement → compliant.

3. Visual inspection of the board → a burn mark on the power section of the compressor relay.

4. Check the wiring → no breaks, but there is moisture near the exterior electrical box.

The conclusion: the main circuit board was defective . A short circuit caused by moisture infiltration had probably damaged the relay.

Repair carried out by AirGreen

1. Replacement for the original Gree control board , ordered directly from the authorized distributor.

2. Drying and cleaning the electrical compartment with a non-conductive dielectric agent.

3. Reconnection of refrigeration lines and verification of static pressure .

4. Full start-up test : compressor active, pressures balanced, discharge temperature at 9°C after 5 minutes.

We also applied waterproof protection to the connections and added a discreet rain cover above the case to prevent any recurrence.

Final result: restored performance and comfort regained

The customer immediately noticed a significant improvement in interior comfort . The air conditioner returned to its nominal efficiency, with quiet and stable operation .
Our team also took the time to explain good maintenance practices:

• Clean the internal filters every 4 to 6 weeks.

• Visually check the cables and drain at the start of each season.

• Schedule an annual AirGreen maintenance service , including a complete cleaning and inspection of the refrigerant circuit.

AirGreen expertise in electronic diagnostics

Circuit board failures are becoming increasingly common in modern HVAC systems. At AirGreen, our technicians are specifically trained to diagnose and repair these sensitive components, following the procedures of manufacturers such as Gree, Fujitsu, Sharp, Midea, Lennox, Trane, and Bosch .

This intervention in Rosemont perfectly illustrates our approach: technicality, transparency and sustainability . Each repair is carried out to extend the useful life of the device, while ensuring optimal energy efficiency.