A rooftop service call for a distressed Fujitsu unit
At AirGreen , our technicians often work in demanding situations—and this was a prime example. We were called to Côte-des-Neiges–Notre-Dame-de-Grâce , on the flat roof of a residential building, to diagnose a Fujitsu wall-mounted heat pump with air conditioning performance issues.
The customer contacted us after noticing that their system was no longer producing cold air and that the outdoor compressor seemed unusually quiet . On site, our team quickly noticed that the outdoor unit, installed on a raised platform, was showing signs of wear related to the weather conditions.
Diagnosis: a hidden electrical fault
The intervention began with a complete inspection of the electrical circuit and the compressor connections .
Here are the main findings:
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The power cables had insulation that had been partially damaged by sunlight and temperature variations.
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A blown internal fuse was preventing the compressor from starting properly.
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The communication cable between the indoor and outdoor unit had been damaged, probably by movement or mechanical stress on the roof.
Our technicians performed voltage and continuity measurements , confirming a loss of signal between the two units of the system. This type of failure is quite common on rooftop installations exposed to the elements, especially when the cables are not perfectly protected in UV-resistant conduits.
Technical intervention: complete overhaul of the wiring and compressor
After isolating the source of the problem, our team undertook the following work:
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Replacement of the communication cable between the indoor and outdoor units.
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Complete overhaul of electrical connections , with heat-shrink tubing and UV-resistant fasteners.
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Replaced blown fuse and tested Fujitsu compressor.
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Checked refrigerant level (R410A) — no leaks were detected.
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Cleaning the condenser and evaporator coil to optimize heat exchange.
Once everything was reconnected, the Fujitsu heat pump restarted without issue. The air outlet pressure and temperature were measured to confirm operation within factory specifications.
Result: restored performance and satisfied customer
After our intervention, the system returned to optimal performance. The indoor temperature dropped from 28°C to 22°C in less than 30 minutes, proving that the heat pump was regaining its full cooling capacity.
The customer, relieved not to have to replace his device, appreciated the transparency of our diagnosis and the thoroughness of the work carried out.
We also took the time to secure the wiring on the roof , to prevent the same problem from happening again due to wind or bad weather.
AirGreen Prevention and Advice
This type of failure clearly illustrates the importance of regular maintenance of rooftop HVAC systems . Exposure to sun, rain, and snow can accelerate the deterioration of cables and connectors.
At AirGreen , we recommend:
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An annual inspection of wiring and connections .
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Installation of additional mechanical protection on external conduits.
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Cleaning the coils to prevent the compressor from overheating.
These simple measures extend the life of appliances and avoid costly repairs in the long run.
Conclusion: AirGreen expertise at the service of Montreal
This Fujitsu wall-mounted heat pump repair in Côte-des-Neiges–Notre-Dame-de-Grâce once again demonstrates our commitment to providing reliable, fast and long-lasting HVAC service .
Each intervention is an opportunity for our technicians to apply the best practices in the sector, adapted to the climatic realities of Greater Montreal.
Whether your system is installed on a roof, facade or ground, AirGreen ensures quality maintenance and repair, with constant attention to detail and safety.
AirGreen — Air Conditioning & Heating in Montreal, Laval, Longueuil, North Shore and South Shore.
Your comfort, our expertise.