An urgent call in a heritage building in Montreal
At AirGreen , we often receive calls related to HVAC systems installed in older buildings in Montreal. Recently, our team was dispatched to a charming apartment in the Côte-des-Neiges neighborhood, where a Zephyr wall-mounted air conditioner was showing signs of malfunction. The indoor unit, installed near a ceiling adorned with antique moldings, had a visible problem: its front panel was partially disassembled, and electrical wires were hanging abnormally.
The customer noticed that the unit was no longer responding to commands and that the indicator light remained off, despite several attempts with the remote control. In a building with high ceilings and limited ventilation, the breakdown of a wall-mounted air conditioner in the middle of autumn—when Montreal's days can still be hot—quickly became uncomfortable.
Accurate diagnosis of a failed system
Our certified technicians performed a complete inspection of the Zephyr system . Upon opening the hood, several observations became apparent:
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The unit was covered in dust and moisture accumulated around the circuit board.
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A loose connection at the power connector prevented the system from powering on.
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The insulation of the control cable, visible in the photo, had been damaged by mishandling during previous maintenance .
We used a digital multimeter to check for continuity and isolate the problem to the main control module . Once the fault was identified, our team carried out a complete rewiring :
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Replacing the power connector .
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Repair and securing of the control cable .
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Deep cleaning of the evaporator and tangential fan , often neglected but essential for performance.
A delicate intervention in a restricted environment
This type of wall installation in Montreal's heritage buildings requires a meticulous approach. The moldings and old walls make dismantling and routing cables more complex. Our technicians had to work carefully to avoid damaging the paint or decorative elements.
The Zephyr air conditioner, typical of 12,000 BTU residential wall-mounted units , was then powered back up after continuity and electrical leak testing. The restart was uneventful, and the unit resumed its normal operating cycle, delivering a steady, quiet flow of air.
Result: comfort and safety restored
At the end of the intervention, we carried out:
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A performance test in cooling mode .
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A check of condensate drainage , often problematic in old buildings.
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A calibration of the indoor temperature sensor to ensure an accurate reading.
The customer immediately noticed the difference: smooth operation, no vibration, and controlled room temperature. In addition to restoring comfort , our team left preventive maintenance recommendations :
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Clean the filters every three weeks during the warm season.
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Check the condition of the control cable every spring.
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Avoid handling the front panel without professional assistance.
AirGreen expertise at the service of sustainability
Electrical faults and poorly insulated connections are a common cause of wall-mounted air conditioner failure in Montreal, especially when the initial installation was carried out without compliance with CSA standards. At AirGreen, we place safety and reliability at the heart of every intervention.
Our mission: to extend the lifespan of HVAC systems and ensure optimal energy efficiency . Thanks to our experience with all major brands – from Zephyr to Midea, Fujitsu, Gree or Sharp – we are able to quickly diagnose and repair any type of problem:
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R-410A or R-32 refrigerant leaks ,
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Electronic card failures ,
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Abnormal noises from the blower motor ,
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Drain or air valve blockages .
A complete service throughout the metropolitan area
Our teams operate across Montreal, Laval, the North Shore, and the South Shore , guaranteeing fast, professional, and compliant service. Whether for preventative maintenance , urgent repairs , or a complete unit replacement , we offer solutions tailored to each type of building, whether it's a modern condo, a century-old duplex, or a rental property.
Conclusion
This repair of a Zephyr wall-mounted air conditioner in Côte-des-Neiges perfectly illustrates our approach: combining technical rigor , aesthetic care and respect for the residential environment . At AirGreen, each intervention is an opportunity to demonstrate our commitment to quality, transparency and customer satisfaction .