A typical service call on the South Shore: a silent compressor on a balcony
At AirGreen , we are regularly called upon to intervene on wall-mounted air conditioning systems installed on condo balconies or terraces, especially on the South Shore of Montreal . That day, our team went to Saint-Lambert to diagnose a Hexzair air conditioner that refused to start despite the rising heat of late spring.
The customer, concerned that he was no longer able to feel fresh air circulating inside, noticed a slight humming noise from the outdoor unit before it stopped working completely. Our mission: to find the cause of the failure and quickly restore the system, while ensuring electrical safety and energy performance.
Diagnosis: an electrical problem located in the cut-off box
Upon arrival, we performed a complete visual inspection of the system. The Hexzair outdoor unit, compact and mounted on a sturdy metal stand, presented a clean installation, but some signs of wear at the electrical connections caught our attention.
Our technicians have checked:
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the supply voltage to the wall circuit breaker;
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the condition of the wiring and insulated connections ;
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the presence of pressure in the R-410A refrigerant circuit of the compressor;
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and the status of the control card .
After measuring with the multimeter, the voltage arriving at the outdoor unit was intermittent , caused by a bad contact in the disconnect box . This type of problem is common when moisture gets into the housing or the terminals become loose over time.
Intervention: cleaning, tightening and testing of the complete circuit
We cut off the main power, dismantled the breaker box , then:
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Cleaned the terminals and contacts using a specific product for electrical components;
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Tighten all connections to ensure perfect continuity of current;
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Replaced the slightly oxidized internal fuse ;
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Checked the grounding of the entire system.
Once these steps were completed, we restored power and restarted the air conditioner . The compressor started running normally again, confirming that the fault was indeed at the disconnect point and not at the internal condenser module.
Hexzair Air Conditioner Performance Check
After rebooting, we let the system run for 20 minutes to measure:
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the pressure of the R-410A refrigerant fluid ;
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the blowing temperature to the indoor unit;
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and the power consumption of the compressor.
The values obtained were fully consistent with the manufacturer's specifications. No signs of overheating or loss of performance were detected.
We also quickly cleaned the condenser grille and advised the customer to do a full preventative maintenance before the height of the summer season , to avoid any breakdowns related to dust or corrosion.
AirGreen expertise: safety and performance above all
This type of intervention demonstrates the importance of professional HVAC repair service . Even a seemingly innocuous breakdown can mask a serious electrical risk or compromise the system's durability. At AirGreen , our certified technicians are experts in electrical diagnostics as well as the thermodynamic and refrigeration aspects of wall-mounted air conditioners.
We always insist on:
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compliance with the Quebec electrical code ;
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cleanliness of connections and drainage;
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checking the grounding ;
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and optimization of energy performance .
Result: a reliable air conditioner and a reassured customer
At the end of the repair, the Hexzair air conditioner was once again operating optimally, blowing at 10°C below the ambient temperature—proof of excellent performance. The relieved client regained the comfort of his Saint-Lambert condo without having to replace the unit.
We also schedule annual preventative maintenance to ensure compressor longevity and system stability. Proper maintenance often helps prevent costly repairs and premature replacements.
In summary
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Device Type: Hexzair Wall-Mounted Air Conditioner (R-410A)
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Location: Saint-Lambert, South Shore of Montreal
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Problem: Intermittent power failure at the disconnect box
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Solution: Cleaning, tightening, replacing the fuse and complete testing
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Result: System returned to service, performance restored to 100%
A trusted partner for your HVAC needs on the South Shore
At AirGreen , we respond quickly throughout Montreal, Laval, Longueuil, the North Shore and the South Shore , whether for the repair , maintenance or replacement of wall-mounted air conditioners . Our interventions are precise, transparent and focused on the lasting satisfaction of our customers.
Are you noticing a noise, an odor, a leak or difficult starting in your air conditioning system?
Contact AirGreen today: our team will efficiently diagnose and repair your device while ensuring its safety and energy efficiency.