Home » Some of Our Service Calls in Greater Montreal » Repair of a Fujitsu wall-mounted heat pump in Plateau-Mont-Royal
Réparation d’une thermopompe murale Fujitsu au Plateau-Mont-Royal
Reading time: 4'

Repair of a Fujitsu wall-mounted heat pump in Plateau-Mont-Royal

A high-rise intervention on a typical Montreal flat roof

At AirGreen , we are often called upon to work in multi-unit buildings where wall-mounted heat pump outdoor units are installed on the roof. This was exactly the case during our recent service call in Plateau-Mont-Royal , an urban neighborhood where residential buildings are often equipped with Fujitsu systems to ensure year-round comfort and energy efficiency.

Our team was contacted by the manager of a six-unit building after several occupants complained about a loss of performance in air conditioning mode on one of the Fujitsu systems installed on the roof.

Initial observation: no cold and abnormal noise from the compressor

Upon arrival, we performed a complete visual inspection of the outdoor unit. The compressor cover was already removed, indicating a prior diagnostic attempt by a third-party technician. Using our digital pressure gauges , we checked the refrigeration circuit pressure and found a charge significantly below the standards: the system had a refrigerant leak .

Additionally, the condenser fan produced an irregular noise, indicating mechanical misalignment caused by premature bearing wear—a common problem on roofs exposed to climate variations and urban debris.

Complete diagnosis: leak, overheating and drop in performance

We followed a methodical procedure:

  1. Fluorescent tracer leak test to precisely locate the leak.

  2. Checking the compressor and electrical connections .

  3. Cleaning the condenser coils , clogged with dust and asphalt particles from the roof.

  4. Thermal analysis of refrigeration ducts to confirm loss of efficiency.

The test revealed a micro-leak on a weld in the compressor outlet tube , caused by repeated vibration and prolonged exposure to sunlight.

Fujitsu Heat Pump Repair and Recommissioning

Once the leak was identified, our technicians undertook the complete repair of the refrigeration circuit :

  • Complete purge of residual R-410A refrigerant according to environmental standards.

  • Reflow and silver resoldering of the defective section of copper pipe.

  • Nitrogen pressure tested to 350 psi to ensure leak-proof.

  • Deep vacuum for 45 minutes to remove all traces of moisture.

  • Complete refrigerant recharge according to Fujitsu specifications .

After recharging, we observed consistent pressure and temperature values : 125 psi at low pressure, 385 psi at high pressure — a sign of a perfectly balanced system.

Results: restored comfort and optimal performance

Once the system was back up and running, occupants immediately noticed the return of strong, consistent cool air to their apartments. The previously excessive outdoor fan noise was gone. We also calibrated the indoor temperature control to stabilize operating cycles and prevent overloads.

This type of repair perfectly illustrates the expertise of our HVAC teams in Montreal:

  • Fast and accurate diagnosis using advanced digital tools.

  • Repairs in accordance with Fujitsu manufacturer standards .

  • Full compliance with environmental protocols when handling refrigerant.

Prevention: Avoiding breakdowns on flat roofs

Heat pumps installed on flat roofs, as is common in Plateau-Mont-Royal, are exposed to:

  • Extreme weather conditions (direct sun, snow, ice, hail).

  • Constant vibrations due to the building structure.

  • Increased risk of corrosion on metal fittings.

At AirGreen , we recommend biannual maintenance for these setups: one in the spring before the cooling season and one in the fall before heating. This maintenance includes:

  • Inspection of welds and refrigeration connections.

  • Check air flow and clean condenser.

  • Testing of pressures and electrical values.

  • Lubricate the fan motor as needed.

Conclusion: proven expertise on Fujitsu systems

This project in the Plateau-Mont-Royal region demonstrates our ability to work in complex urban environments and on high-rise installations. Through targeted leak repair , in-depth maintenance , and a system upgrade , we were able to restore the Fujitsu heat pump to its original efficiency—for lasting occupant comfort and peace of mind for the building manager.

At AirGreen , we do more than just repair: we ensure the long-term performance and reliability of your HVAC systems , in Montreal, Laval, on the North Shore and the South Shore .