Technician’s report
AirGreenAir conditioning & heatingRBQ 5645-9605-01
Job report

LG wall-mounted air conditioner repair in Sainte-Dorothée

ServiceRepairUnitWall-mounted air conditioner
BrandLGAreaSainte-Dorothée (Laval)
PublishedApril 8, 2026Reading2 min

Attachment 1 · job photo

Réparation d’un climatiseur mural LG à Sainte-Dorothée

Rapid intervention in a family residence in Laval

At AirGreen , we often receive calls about wall-mounted air conditioners that have been installed for several years, but whose performance is gradually declining. This was the case in Sainte-Dorothée , a quiet residential area of ​​Laval , where a customer contacted us about an LG wall-mounted air conditioner that had stopped blowing cold air for several days.

The unit, installed in the main living room, was still operating in ventilation mode, but the air outlet temperature remained lukewarm, despite being set to 18°C.

Diagnosis: Refrigerant leak and overloaded compressor

After a complete examination of the system, our RBQ certified technician detected two major anomalies:

  • A significant drop in pressure in the refrigeration circuit, indicating a refrigerant leak.

  • A compressor in thermal overload , due to prolonged operation in cold mode without sufficient gas.

Using an electronic leak detector, we located the source of the problem: a microleak at the flare connection connecting the copper pipe to the indoor unit. This failure is common in older installations, often caused by repeated thermal expansion of the metal.

Repair carried out by AirGreen

Our experts carried out a complete repair of the circuit :

  1. Safe recovery of remaining refrigerant in accordance with environmental standards.

  2. Replacement of the flare joint and calibrated tightening using a specialized torque meter.

  3. Leak test with high pressure nitrogen to verify the strength of the repair.

  4. Creation of a complete vacuum in the circuit in order to eliminate any residual moisture.

  5. Recharge with R410A refrigerant according to LG factory specifications.

  6. System restart and calibration with superheat and subcooling measurement.

The unit has resumed normal operation, displaying a blow-out temperature of 9°C , confirming optimal performance.

Result: restored comfort and reduced consumption

Thanks to this intervention, the customer immediately regained the original thermal comfort of his device. In addition, the air conditioner's power consumption was reduced, since the compressor no longer exerts unnecessary force.

Our checks showed stable operation in auto mode, without noise or vibration. The unit was also thoroughly cleaned: filters, fins and evaporator.

AirGreen Tips to Extend the Life of Your Wall-Mounted Air Conditioner

Our technicians recommend a few simple actions:

  • Clean filters every 4 to 6 weeks during the summer season;

  • Schedule a complete annual maintenance including refrigerant pressure check;

  • Avoid leaving the unit in cooling mode when outside temperatures are below 10°C;

  • Watch for unusual noises or odors, often early signs of drainage or engine problems.

AirGreen: HVAC repair experts in Laval and throughout Greater Montreal

At AirGreen , we offer our expertise to individuals and condominiums for the repair, maintenance and installation of HVAC systems of all brands: LG, Gree, Fujitsu, Samsung, Midea, Sharp, Goodman, Bosch , and more.

Our teams serve Laval, Montréal, Longueuil, the North Shore and the South Shore, offering fast, transparent service that meets current standards (RBQ licence 5645-9605-01).

Every service call is an opportunity for us to guarantee our customers safety, comfort and energy efficiency .

Report published by AirGreen Climatisation & Chauffage · RBQ licence 5645-9605-01 (15.8, 15.10, 16)airgreen.ca · 514 316-2973
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  • RBQ licence 5645-9605-01Subclasses 15.8, 15.10 and 16
  • $5M liability insuranceOn every job
  • 15+ yearsFamily-owned, based in Montréal