A roofing service call: when AirGreen expertise makes all the difference
On a sunny morning in Pointe-Claire , our technicians were dispatched for a service call on a Fujitsu wall-mounted heat pump installed on the flat roof of a small commercial building. This type of installation—often exposed to the elements and temperature fluctuations—requires rigorous maintenance. The customer had reported an intermittent failure in heating mode and an abnormal noise coming from the outdoor compressor .
Accurate diagnosis of a combined electrical and refrigeration problem
Upon arrival, our technicians performed a thorough inspection of the outdoor unit. The Fujitsu wall-mounted heat pump was mounted on a treated wood base, raised to avoid direct contact with the roof surface. This type of mounting is typical of flat roof installations: it protects against water accumulation and vibrations.
The audits revealed two critical points:
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A poorly insulated power cable at the disconnect box — probably due to prolonged exposure to UV rays.
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A slight leak of R-410A refrigerant was detected at the flare fitting at the compressor inlet.
These two anomalies explained the intermittent breakdown: the heat pump went into safety mode when the fluid pressure fell below the minimum threshold, resulting in a loss of heating performance .
AirGreen intervention: safety, precision and reliability
Our technicians proceeded in stages, respecting electrical and environmental safety protocols:
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Replacement of faulty wiring and resealing of the cut-off box with waterproof conduit.
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Repair of the leak at the flare fitting, tightening to torque and leak testing with nitrogen.
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Complete recharge of the system with R-410A according to the specifications of the manufacturer Fujitsu.
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Cleaning the condenser to optimize heat exchange and reduce fan noise.
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Final check : pressure, superheat and subcooling measurements – everything was correct.
Result: restored performance and restored peace of mind
By the end of the project, the heat pump was back operating at full capacity. Heating was stable, quiet, and energy-efficient . The client, relieved to regain consistent comfort inside the building, was also advised on implementing a preventative maintenance plan —essential for rooftop units, which often receive more stress than those mounted on the ground.
The importance of regular maintenance on rooftop installations
HVAC systems placed on flat roofs, as in this case in Pointe-Claire, are subject to more:
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Significant thermal variations (summer/winter).
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Prolonged exposure to UV rays and winds .
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Amplified vibrations if the base is not perfectly stable.
This is why AirGreen recommends:
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A complete inspection twice a year (spring and fall).
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Professional cleaning of the condenser .
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Systematic checking of electrical and refrigeration connections .
These simple actions extend the life of the unit and reduce the risk of costly breakdowns.
AirGreen expertise at your service in Montreal and its surrounding areas
At AirGreen , we put our expertise at the service of residents and businesses in Montreal, Laval, Longueuil, the North Shore and the South Shore . Our team is proficient in Fujitsu, Midea, Gree, Sharp, Goodman, Lennox, Bosch systems and several other well-known brands. Each intervention is carried out with the same rigor: precise diagnosis, lasting repair, and total transparency .
Whether it is an electrical failure , a refrigerant leak , or a decrease in heating performance , our certified technicians find the most effective solution to restore the comfort of your spaces.
Do you suspect a problem with your wall-mounted heat pump?
Unusual noise, lack of heat, or persistent frost on the condenser are often warning signs of a technical problem. Don't wait for the problem to get worse. Contact AirGreen today for fast, professional repairs —all across Greater Montreal.
AirGreen – Your trusted HVAC expert in Pointe-Claire and throughout Greater Montreal.