Cooling failure in the middle of a hot day
At AirGreen , we know that a Quebec summer can quickly become stifling when a wall-mounted heat pump stops working properly. This is what happened to a homeowner in Brossard , on the South Shore of Montreal , whose LG wall-mounted heat pump no longer produced cold air despite a compressor apparently being on.
Our team attended the site to diagnose and repair this unit, which was installed on a sturdy exterior wall mount and well maintained.
Inspection and first diagnosis: a significant loss of performance
Within the first few minutes, our technician noticed that the outdoor unit was working, but the indoor fan was blowing lukewarm air . No errors were displayed on the remote control, but the system was experiencing a pressure imbalance characteristic of a lack of refrigerant.
After a careful visual inspection:
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No obvious signs of oil leakage or corrosion,
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Well insulated piping,
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Stable wall mount without excessive vibration.
We then connected the pressure gauges to confirm the pressures: the verdict was clear — the system was partially discharged .
Leak detection and repair
To ensure a lasting repair, our team followed a precise protocol:
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Drawing the remaining refrigerant into a recovery cylinder.
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Nitrogen pressurization to detect microleaks: a slow loss was detected at the liquid side flare connection , probably due to a slight loosening caused by thermal variations.
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Repair the fitting : controlled tightening, replacement of the seal and repeated pressure test until stabilization.
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Complete vacuum of the circuit (500 microns) to eliminate all humidity.
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Recharge the system with the exact amount of R-410A according to LG specifications.
Performance tests and final calibration
Once the recharge was complete, the technician carried out a complete check of the pressures and temperatures . The values were perfect:
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Low pressure: 118 psi,
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High pressure: 390 psi,
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Temperature difference between blown air and ambient air: 19°C,
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Power consumption within expected limits.
After a period of observation, the indoor air became cold, stable and quiet again.
The Importance of Correct Torque on Flare Fittings
One of the key aspects of this intervention was the quality of the initial assembly . Even if the LG system is known for its reliability, a poorly tightened connection or one without sealing paste can create micro-leaks in the long term.
At AirGreen, we always insist on following the manufacturer's prescribed torque values , using calibrated tools and applying R-410A specific sealing compound to ensure system durability.
The repaired LG model: compactness and recognized efficiency
This LG wall-mounted heat pump , with a capacity of approximately 12,000 BTUs , is very popular in homes on the South Shore. Compact, quiet and efficient, it provides both heating and air conditioning thanks to a variable-speed inverter compressor .
However, even the best systems require regular maintenance :
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Cleaning the internal filters every 2 to 3 months,
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Inspection of refrigeration connections once a year,
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Check pressures before each summer.
AirGreen Expertise: Fast and Reliable Service in Brossard
The intervention took less than two hours, with the system fully up and running upon our departure. The client praised the speed, accuracy, and transparency of the service.
Our teams are trained to work on all brands— LG, Midea, Fujitsu, Sharp, Gree, Mitsubishi, and many others —and have all the necessary equipment to perform accurate on-site diagnostics.
Whether in Montreal, Laval, Longueuil or on the North Shore and the South Shore , AirGreen guarantees professional, certified and sustainable HVAC service.
AirGreen Tips to Avoid Future Leaks
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Have your fittings inspected at least once a year, especially after a harsh winter.
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Avoid vibrations : a poorly fixed wall bracket can cause micro-cracks in the pipes.
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Clean the outdoor unit in the spring to prevent dust and debris from accumulating.
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Schedule annual maintenance to maintain your system's energy efficiency.
These simple steps will extend the life of your LG heat pump and ensure consistent performance throughout the year.
Result: comfort restored in Brossard
Thanks to our quick and methodical intervention, the Brossard client's LG wall-mounted heat pump is operating at full capacity again. The home has regained a pleasant, quiet, and energy-efficient indoor climate.
At AirGreen , every repair is carried out with the same commitment: technical rigor, customer satisfaction and lasting performance .
AirGreen – Specialists in repair, installation and maintenance of HVAC systems in Montreal, Laval, Longueuil, North Shore and South Shore.