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Réparation d’un système VRF LG à Côte-des-Neiges
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Repair of an LG VRF system in Côte-des-Neiges

A complex intervention in an underground parking lot in Côte-des-Neiges

At AirGreen , we were recently called for an HVAC repair in a commercial building in the Côte-des-Neiges district of Montreal. The client, a building manager, reported a breakdown on an LG Inverter VRF system , which is essential for the comfort of the offices and businesses located on the upper floors.

The installation was located in an underground parking lot , where several LG outdoor units were aligned side by side on a concrete wall. This type of configuration is typical of VRF (Variable Refrigerant Flow) systems , chosen for their energy efficiency and their ability to simultaneously supply several independent zones.

Diagnosis: an intermittent failure on a master unit

Upon arrival, our certified technicians performed a complete analysis of the VRF system . Several error codes were appearing on the central controller, indicating intermittent communication between the master unit and the secondary modules .

After inspection:

  • We noticed partial fouling of the condenser of one of the LG units.

  • A voltage variation was also recorded on the power supply circuit, possibly due to an electrical overload in the parking lot.

  • The communication connectors (data bus) showed slight oxidation , caused by the ambient humidity of the basement.

These three factors combined explained the random shutdowns and loss of system performance.

Repair and recommissioning

Our specialists undertook a complete cleaning of the heat exchangers and ventilation grilles using a biodegradable degreaser suitable for VRF condensers.

Then we have:

  1. Replaced the communication connectors between the master and slave units.

  2. Checked wiring continuity and tightened electrical connections.

  3. Measured the pressure of R-410A refrigerant to ensure the stability of the thermodynamic cycle.

  4. Reprogrammed the master/slave sequence on the LG control module.

Once these interventions were carried out, soft start tests confirmed a complete return to nominal performance . The system returned to its optimal energy efficiency , and the temperature stabilized in all interior areas.

AirGreen expertise: intervention in complex environments

Underground parking often represents a technical challenge:

  • Reduced ventilation , therefore increased risk of condensation and overheating.

  • Restricted access requiring mobile diagnostic equipment.

  • Multiple units sharing the same electrical circuits.

At AirGreen, we have developed specific procedures for VRF systems in restricted environments , guaranteeing:

  • A quick and precise diagnosis ,

  • Reduced downtime ,

  • And preventive maintenance adapted to the environment.

Recommended Maintenance for LG VRF Systems

To extend the life and reliability of this type of system, we recommend:

  • A complete maintenance twice a year (spring and fall).

  • Checking airflow and refrigerant level at each inspection.

  • Preventive cleaning of electronic boards exposed to humidity.

  • Monitoring electrical voltages in industrial environments.

These simple actions help prevent costly breakdowns and maintain the high energy efficiency of VRF systems.

Result: comfort restored and manager satisfied

A few hours after our intervention, the customer confirmed that:

  • The indoor temperature was stable across all floors.

  • No alarms had reappeared on the control panel.

  • The building's electricity consumption had decreased slightly, a sign that the units were once again operating at their rated efficiency.

This success once again demonstrates the versatility and competence of our teams in commercial HVAC system repair in Montreal .

AirGreen: your HVAC partner in Montreal and on the North and South Shores

Whether you own a commercial building in Montreal , manage a condo in Laval , or are responsible for an industrial building on the South Shore , AirGreen is your trusted partner for:

  • Maintenance and repair of VRF systems (LG, Mitsubishi, Daikin, Fujitsu, etc.).

  • Advanced diagnostics in complex environments.

  • Energy modernization of your existing installations.

Each intervention is carried out according to the highest technical standards , with an approach focused on reliability and durability .