A quick intervention on a typical Montreal flat roof
At AirGreen , we were called for an HVAC repair service in Outremont , a neighborhood with many flat-roofed residential buildings. Our client, a duplex owner, contacted us after noticing that his Fujitsu wall-mounted heat pump had not been providing heat for a few days, despite a recent system restart and filter maintenance.
On site, our team quickly identified an outdoor compressor installed on the roof , typical of Montreal's urban configurations, connected to several indoor units. The weather conditions were not ideal—light rain and strong winds—but this did not slow down our diagnosis.
Complete diagnosis: an underestimated electrical problem
Upon initial visual inspection, we noticed a complex routing of electrical cables and refrigeration lines , likely shared with other systems on the same roof. This type of installation, often found in multi-unit buildings, requires special attention to isolate the correct circuit.
After some electrical testing, our technician identified a loose connection in the compressor wiring , caused by water infiltration into a junction box. This problem prevented the compressor from starting properly, resulting in no heating.
At the same time, we measured the R-410A refrigerant pressures, which were found to be compliant. No leaks were detected—a good sign for a Fujitsu unit that's over eight years old.
Repair: securing, replacement and complete testing
To ensure a lasting solution, we have:
-
Isolated the faulty circuit and temporarily cut off the main power supply.
-
Replaced the junction box with a waterproof model for outdoor use, compliant with CSA standards.
-
Re-make the electrical connections inside the condenser using heat shrink terminals to prevent further infiltration.
-
Cleaned and secured the cables as they ran through the roof using cable ties and UV sheaths.
Once the repair was completed, we performed a test in heating mode for 20 minutes: the compressor started without hesitation, the pressure stabilized, and the indoor units began to blow constant warm air around 40°C.
Result: restored performance and assured prevention
The customer immediately noticed the difference: restored comfort, normalized operating noise, and above all, no random shutdowns after several cycles. We also recommended annual preventative maintenance , which is essential for systems installed on flat roofs exposed to the elements.
To extend the life of your Fujitsu heat pump, we recommended:
-
Check electrical connections at each seasonal inspection.
-
To install a condenser protection shelter , useful against snow and acid rain.
-
To prevent the accumulation of debris around refrigeration cables and pipes.
AirGreen Expertise: Safety and Reliability Above All
Every rooftop HVAC repair comes with its challenges—difficult access, moisture, and exposed wiring. Our AirGreen -certified technicians handle these tasks with rigor and precision, while adhering to Montreal's current electrical and environmental standards.
Thanks to our experience on Fujitsu , Midea , Gree or Sharp systems, we are able to quickly diagnose faults and restore the performance of a system in a single visit.
Why choose AirGreen for your wall-mounted heat pump repairs in Montreal?
-
Precise and rapid diagnosis , even in complex installations.
-
RBQ certified technicians specializing in urban roofing.
-
Guaranteed repairs , parts and labor included.
-
Service available throughout the metropolitan region: Montreal, Laval, Longueuil, North Shore and South Shore .
At AirGreen, we believe that a successful repair goes beyond simply replacing parts: it relies on a complete understanding of the system and the actual installation conditions. It's this comprehensive approach that gives our customers peace of mind—no matter the weather or season.