A quick service call for a broken CPU in the middle of summer
At AirGreen , we know that an air conditioning system that breaks down on a hot day can quickly become an emergency. This is exactly what a homeowner in Brossard , on the South Shore of Montreal , experienced when he contacted us about a York central heat pump that was no longer blowing cool air despite the compressor being on.
Our team was dispatched to the site the same day to perform a complete diagnosis of the HVAC system , including checking the compressor, fan, wiring and refrigerant levels.
System Description
The client had a York central heat pump installed outside, against a red brick wall typical of single-family homes in the area. This large capacity model (approximately 3 tons / 36,000 BTU ) provides both summer cooling and mid-season heating , in conjunction with an interior duct system.
The outdoor unit sat on a slightly sloped concrete slab and showed signs of wear from several seasons without professional maintenance. The refrigeration ducts were insulated, but the protective coating showed cracks—a potential indicator of decreased energy efficiency.
Diagnosis: search for the cause of the breakdown
Our technician proceeded in stages:
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Visual and mechanical inspection
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No major damage visible on the compressor.
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The outdoor unit was relatively clean, but leaves and plant debris were partially obstructing airflow.
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Electrical tests
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Correct supply voltage.
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Weak starting capacitor : measured voltage was 30% lower than nominal.
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Checking the refrigeration cycle
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Abnormal pressures: slightly too low at suction, suggesting a partial lack of refrigerant .
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No signs of leakage visible to the naked eye, but the technician used an electronic detector to confirm the presence of a micro-leak on a flare fitting .
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Repair carried out
The intervention took place in three main stages:
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Replacing the starting capacitor
A new genuine York capacitor was installed, ensuring smooth compressor restart and extending motor life. -
Repair of the refrigeration connection
The fitting with the microleak was disassembled, cleaned, and tightened with a new sealing ring. A nitrogen pressure test then confirmed the absence of a leak. -
R-410A refrigerant recharge
Adjusting the refrigerant level restored the ideal pressure according to York specifications. The values measured after the intervention were perfectly in line with the manufacturer's recommendations.
Results and performance after repair
As soon as it was restarted, the difference was immediate. The system resumed its normal cooling cycle , with air blowing at 9°C in the ducts and a stable discharge temperature.
The owner noted that the compressor sound was noticeably smoother and quieter , a sign of optimal operation. We also recommended installing anti-vibration mounts to reduce resonances on the front of the house.
AirGreen Maintenance Recommendations
A central heat pump like this, while robust, requires annual maintenance to avoid costly breakdowns. We advised the client:
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Have the outdoor coils cleaned every spring.
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Replace interior air filters every three months.
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Have the refrigerant charge and electrical connections checked before each summer season.
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Ensure a minimum clearance of 60 cm around the condenser for adequate ventilation.
These simple actions help reduce energy consumption and extend the life of the HVAC system.
AirGreen Expertise on the South Shore
This intervention in Brossard perfectly illustrates our mission: to offer fast, professional and transparent service to our residential clients on the South Shore, Laval, Montreal, and the North Shore .
With our team of certified technicians , we service all major brands— York, Trane, Lennox, Goodman, Carrier, Daikin, Fujitsu, Gree, and more —ensuring long-lasting repairs that meet manufacturer standards.
Assessment of the intervention
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Device Type: York Central Heat Pump
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Location: Brossard, South Shore of Montreal
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Problem: No cold, compressor running continuously
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Causes identified: Defective capacitor and micro-leak on connection
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Solution: Replace the capacitor, repair the leak, completely recharge with R-410A
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Result: Cooling restored, quiet and efficient system
AirGreen: the benchmark in central heat pump repair
With years of experience in the field of heating, ventilation and air conditioning , AirGreen remains a trusted choice for all your HVAC repair, installation and maintenance needs in Montreal, Laval, Longueuil and on both shores .
Our promise: accurate diagnostics , lasting repairs and human and professional service , reflecting our commitment to the satisfaction of each customer.