A service call on a flat roof in Montreal
At AirGreen , our technicians regularly work on HVAC systems installed in multi-unit residential buildings in Montreal. On this day, our team was dispatched to the Côte-des-Neiges–Notre-Dame-de-Grâce neighborhood for a service call on a Goodman central heat pump installed on the roof of a red brick building.
The unit, a Goodman central heat pump weighing approximately 3.5 tons , provided both heating and cooling for the units through a network of interior ducts. The customer reported a loss of efficiency in heating mode and random shutdown of the system despite a functioning thermostat.
In-depth diagnosis of the fault
Upon our arrival, we carried out a complete inspection of the outdoor condenser, installed on treated wooden supports to avoid direct contact with the roof gravel. Visually, no major signs of deterioration were visible: no excessive frost, no apparent oil leaks.
Our technicians then:
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Checked the power supply voltage at the electrical box. Everything was correct.
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Checked the R-410A refrigerant pressure : levels were slightly lower than normal, indicating a probable micro-leak .
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Inspected the electrical connections and the compressor start capacitor . The latter showed a reduced value of 28 µF for a nominal specification of 35 µF — a sign of component aging .
After a continuity test and a forced cycle, we confirmed that the heat pump was having difficulty reaching the set temperature due to a combination of minor leakage and loss of capacitor capacity .
The steps of repair
Our intervention took place in three parts:
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Capacitor Replacement : We have installed a new Goodman compatible model of equivalent capacity to ensure smooth compressor start-up.
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Leak detection test : Using an electronic detector, we located a very small leak at the Schrader fitting of the low-pressure service line. After purging and brazing, the leak was sealed.
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R-410A refrigerant recharge : the charge has been precisely adjusted according to the nominal pressures and ambient temperature, for optimal performance.
Once these steps were completed, we performed a full cycle in heating mode , measured the blowing temperatures and power consumption . The system returned to stable operation, with an efficiency greater than 98% of its original performance .
Results and customer satisfaction
After our work, the building manager noted consistent heat in all units and a significant reduction in outside noise . The heat pump, now perfectly balanced, ensures optimal comfort even during periods of thaw and frost.
We also have:
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Cleaned the evaporator fins to improve heat exchange.
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Checked the operation of the reversing valve to ensure smooth transition between air conditioning and heating modes.
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Advised the customer on bi-annual preventative maintenance to prevent debris build-up on the roof and extend the life of the compressor.
AirGreen expertise: reliability, safety and performance
This type of intervention perfectly demonstrates our approach: combining rigorous diagnosis , technical expertise , and compliance with Quebec HVAC standards . Goodman central heat pumps are known for their robustness, but like any mechanical system, they require regular professional maintenance to maintain their efficiency season after season.
At AirGreen , we serve Montreal, Laval, Longueuil, the North Shore and the South Shore , and we work on both central systems and wall-mounted units . Our priority is always the same: ensuring the comfort and peace of mind of our customers while optimizing the energy performance of their installations.
In summary:
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Brand: Goodman
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Type: Central heat pump
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Problem: Intermittent starts, poor heating
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Cause: Weakened capacitor + micro-refrigerant leak
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Solution: Capacitor replacement, soldering, R-410A recharge
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Result: Restored performance, stable comfort, controlled consumption
A trusted partner for your HVAC needs
Whether it's for an urgent repair , a preventive inspection , or the complete replacement of a central system , trust AirGreen , your local HVAC partner in Montreal. Our certified teams are ready to intervene quickly, with original parts and methods that meet the highest industry standards.