Repair of a Gree wall-mounted heat pump in Villeray–Saint-Michel–Parc-Extension

Rapid intervention in a brick residential building in Montreal

At AirGreen , our team was recently called for a service call on a Gree wall-mounted heat pump installed in a residential building in Villeray–Saint-Michel–Parc-Extension, Montreal. This call illustrates our expertise in maintaining and repairing HVAC systems in dense urban environments, where installations must combine performance, silence, and durability.

Context of the intervention

The owner of a red brick triplex noticed that two outdoor units installed on the back wall were no longer producing the expected heat as cool spring evenings approached. One unit seemed to freeze prematurely, while the other shut down after only a few minutes of operation.
These symptoms possibly indicated a refrigerant leak or a circuit board problem —two common causes in facilities exposed to intensive heating and cooling cycles.

Field diagnosis

Our certified technicians arrived on site with all the necessary diagnostic equipment. After a thorough inspection, the following findings were revealed:

• Abnormal pressures in the refrigeration circuit : the main unit displayed a refrigerant level below the standards recommended by Gree.

• Ice buildup on the return line : a clear sign of load imbalance and lack of fluid.

• Outdoor fan slightly obstructed : small leaves and urban dust were reducing the efficiency of the condenser.

• Slightly damaged secondary control board causing intermittent compressor shutdown.

Repair Steps

1. Recovery and draining of remaining refrigerant

We first recovered the existing refrigerant , then cleaned the circuit using a vacuum pump to remove moisture and impurities.

2. Search and seal the leak

Using an electronic detector , we located a micro-leak on a flare fitting located behind the lower outdoor unit. After partially dismantling the protective panel, we tightened and sealed the fitting using a reinforced copper gasket .

3. Replacing the control board

The damaged electronic card was replaced with an original Gree model from the LOMO+ series , ensuring perfect compatibility and better management of compressor modulation.

4. Recharge with R410A refrigerant and calibration

The system was recharged to nominal pressure and then tested in heating and cooling mode. Temperature and pressure readings were found to be stable and within manufacturer specifications.

5. Complete cleaning and final testing

Before leaving the premises, our technicians cleaned the condenser and checked the air circulation. The complete cycle completed without any anomalies, confirming the system's return to full performance .

Result: performance and reliability restored

After our work:

• The automatic compressor defrost is working properly again.

• The indoor temperature stabilizes more quickly.

• Power consumption was reduced by about 15% according to the customer after a few days of use.

• Both units now operate in perfect synchronization, without unwanted vibrations or noise.

Recommended best practices

We took advantage of this visit to advise the owner on preventive maintenance:

• Clean the internal filters every 4 to 6 weeks.

• Clear the space around outdoor condensers , especially in Montreal's narrow alleys.

• Schedule a complete annual maintenance before the cold season to prevent ice buildup and recurring leaks.

AirGreen expertise in Montreal

Our work in Montreal's typical brick buildings requires careful planning, including managing restricted access, electrical constraints, and close proximity. Thanks to our experience, we ensure clean, safe repairs that comply with the strictest HVAC standards.

At AirGreen , we work every week in neighborhoods like Villeray, Rosemont, Ahuntsic, Outremont and Le Plateau , always with the same priority: providing lasting comfort and maximum energy efficiency .

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AirGreen , your trusted HVAC partner in Montreal, Laval, Longueuil, on the North Shore and the South Shore , provides repair, maintenance and installation of heat pumps from Gree, Fujitsu, Midea, Sharp, Zephyr, Trane and many other well-known brands.