During a recent service call in the Mercier–Hochelaga-Maisonneuve district in Montreal, our team of HVAC repair experts was called to diagnose an issue with an LG wall-mounted heat pump installed high up on a back balcony. The system, although recently installed according to the homeowner, was showing signs of malfunction during heating, despite its newness.
At AirGreen, we know that an installation at height, while protected from snow and ice, can hide other types of problems, such as excessive vibrations, improper condensation drainage, or loose refrigeration or electrical connections.
Thorough Inspection of the LG Outdoor Unit
The LG compressor unit was mounted on metal brackets on the brick wall, elevated, clear of the ground, and sheltered from the elements by a balcony roof. This type of installation is quite common in dense areas like Mercier–Hochelaga-Maisonneuve, where space on the ground is limited.
However, within the first few minutes of our inspection, several critical issues were identified:
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Unusual vibration from the outdoor unit felt on the balcony structure, suggesting an imbalanced fan or insufficient bracket securing.
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Intermittent noise in heating mode, potentially indicating fan motor slowdown or an issue with the motor.
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Light frosting on the refrigerant pipes, signaling a potential pressure issue or malfunction with the defrost cycle.
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Stagnant condensation in the drainage tray, not draining properly outside.
Technical Diagnosis and Full System Check
Our certified technicians first cut off the power supply to check the electrical connections inside the unit. Everything appeared to be correctly connected, with no signs of short-circuits or burn marks on the components. Next, we performed a full refrigerant pressure test (R410A in this case), which turned out to be slightly below the standard for the ambient temperatures of the day.
We then conducted a leak test on the refrigeration fittings, particularly where the inner wall unit connects. No leaks were found, which ruled out a significant loss of refrigerant. The likely cause of the issue was therefore a slight undercharge or calibration error of the system during installation.
Corrections and Adjustments Made
Our concrete interventions included:
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Reinforcing the wall brackets to minimize vibrations during operation—a key comfort factor for the occupants.
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Rebalancing the outdoor fan, one of the blades being slightly deformed.
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Adding refrigerant (R410A) to bring the system up to the optimal levels based on the outside temperature.
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Cleaning the condensation tray and adjusting the drainage pipe to a steeper angle, allowing for better water exit.
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Complete testing of the heating and cooling modes, confirming that everything was now functioning properly.
Customer Context and the Importance of Proper Installation
The client, a longtime resident of the area, had recently installed this LG wall-mounted heat pump to improve energy efficiency and reduce reliance on electric radiators. However, some slight oversights in the initial installation were causing these issues on a daily basis.
At AirGreen, we always stress the importance of a meticulous installation, especially when it’s done on elevated structures like balconies. A poorly set-up but high-performance unit can become noisy, inefficient, or even cause long-term risks.
Final Result and Customer Satisfaction
After our intervention, the system is now working quietly and efficiently, with good airflow of warm air indoors. The customer expressed their satisfaction with our speed, technical transparency, and attention to detail, which are core values at AirGreen.
We also took the time to explain to the homeowner how to perform basic seasonal maintenance, including:
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Checking the interior filters every two months.
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Visually cleaning the outdoor unit in spring and fall.
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Watching for signs of excessive condensation or noise.
Why Choose AirGreen for Your Heat Pump Repair in Montreal?
At AirGreen, we bring unique expertise in diagnosing and repairing wall-mounted heat pumps in Montreal, Laval, Longueuil, and the North and South Shores. Our team stands out for:
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A deep knowledge of brands like LG, Fujitsu, Gree, Bosch, and more.
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A rigorous, performance-oriented approach.
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Complete transparency during our service calls.
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Tailored interventions based on architectural environment and the client’s real needs.
Whether it’s for a heating issue, cooling problem, or annual preventive maintenance, we respond quickly with practical, long-lasting solutions.