A service call to an overheated laundry room
This AirGreen service project took us to a home in the Côte-des-Neiges–Notre-Dame-de-Grâce neighborhood (Montreal) , where a client was experiencing a problem with an LG wall-mounted air conditioner installed above the laundry room. The indoor unit, located just above the door, had refused to produce cold air for several days, despite the remote control's functional controls.
The cramped space and the presence of household appliances, including an LG condenser dryer and an AO Smith water heater , made the diagnosis more complex than usual — a perfect environment to test the accuracy and methodology of our HVAC technicians.
Initial diagnosis: no cooling and accumulated heat
The customer noticed that the room temperature was no longer decreasing, even after several hours of use. During our inspection, we confirmed several typical symptoms:
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Warm air coming out of the indoor unit.
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Flashing light on the front panel, indicating a communication error.
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Outdoor compressor not active , although the indoor fan was operating normally.
Our first hypothesis: a problem with the electronic card or communication between the units .
Steps of detailed diagnosis
1. Electrical check
We started by checking the supply voltage to the indoor unit. The voltage was stable at 230V, indicating that the circuit breaker and main power supply were not at fault.
Next, we checked the signal voltage (DC communication between units): the measurement fluctuated abnormally, confirming a failure of the internal control board .
2. Inspection of the electronic card
After removing the top cover, the control board showed traces of humidity and light oxidation , probably caused by condensation from the laundry room.
The warm, humid environment of a room containing both a water heater and a dryer is a known aggravating factor for this type of failure on LG Inverter systems.
3. Checking the temperature probes
We also measured the resistance values of the evaporator and room thermistors . The values were within the manufacturer's specifications, confirming that the problem was indeed confined to the electronic board.
Control Board Repair and Replacement
Once the diagnosis was confirmed, we proceeded to:
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Safe disconnection of the system and complete removal of the control board.
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Cleaning the electronics compartment with dry air and isopropanol to remove all traces of moisture.
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Installation of an original LG card , compatible with the exact model of the unit (LSQ12HV series).
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Reprogramming the initialization parameters for synchronization between the indoor and outdoor units.
After reassembly, we carried out a complete test phase in air conditioning mode. The outdoor compressor started normally, and the air outlet temperature quickly dropped to 7.4°C , indicating optimal performance.
Technical Analysis: Why Electronic Boards Fail
Control board failures are common in installations located in damp rooms such as laundry rooms or basements.
The main causes include:
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Excessive condensation around electronic components.
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Lack of sufficient ventilation , preventing heat dissipation.
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Electrical surges due to network fluctuations.
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Contamination by dust and textile fibers in domestic environments.
At AirGreen , we always recommend protecting indoor units installed in technical areas with an additional air filter and a local dehumidifier , in order to extend the life of the boards and sensors.
Results: restored freshness and secure system
After the repair, the results were immediate:
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Air blown at 7.4°C , in line with the optimal operating range.
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Perfect communication between units.
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Complete disappearance of the error code.
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Resumes quiet and stable operation, without vibration.
The customer was able to see the rapid return of comfort in his laundry room and chose to add our annual AirGreen maintenance program , in order to avoid any future recurrence.
AirGreen Tips: Extend the Life of Your LG Wall-Mounted Air Conditioner
To avoid similar breakdowns, we recommend:
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Have electronic boards inspected once a year, especially in areas of high humidity.
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Clean air filters every 4 to 6 weeks.
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Install a dedicated surge protector to protect sensitive electronic components.
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Avoid obstructing air circulation around the wall unit.
Regular maintenance is the best way to ensure consistent performance, reduced energy consumption and lasting peace of mind.
An intervention by AirGreen: expertise and reliability in Montreal
This project illustrates the rigor and precision that AirGreen is known for in the metropolitan region.
Our technicians combine advanced diagnostics, long-lasting repairs and personalized advice to guarantee each customer a high-performance and reliable HVAC system, whether it is an LG, Fujitsu, Midea, or any other model wall-mounted air conditioner.