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 balcony heat pump that was no longer cooling: a meticulous intervention by AirGreen

At AirGreen , we are often called upon to work in apartment buildings in the Plateau-Mont-Royal region , where wall-mounted heat pumps are frequently installed on rear balconies . These installations, although efficient and compact, are often subject to specific conditions: limited space, lack of ventilation and exposure to urban dust.

It was in this context that a triplex owner contacted us. His Fujitsu wall-mounted heat pump , installed on a small wooden terrace, was no longer able to cool the apartment. The interior fan was working, but the blown air remained lukewarm , even after several minutes of use.

Initial diagnosis: complete on-site analysis

Upon our arrival, we conducted a complete inspection of the HVAC system . The outdoor unit, securely mounted on two treated wooden blocks, was exposed to rain and temperature fluctuations. The compressor was starting, but we noticed:

  • A significant drop in pressure of the R-410A refrigerant .

  • A slightly frosted coil at the condenser outlet.

  • A buildup of debris and dust on the fins.

All these signs pointed to a microleak in the refrigeration circuit - a classic situation when the system has been in use for several years.

Step 1: Leak detection and leak test

We isolated the refrigeration circuit and injected pressurized nitrogen to identify the leak. After a few minutes, the pressure gauge indicated a drop in pressure , confirming our hypothesis.
The leak was coming from a solder connection on the liquid pipe, near the exterior wall. This type of leak can be caused by:

  • Constant vibration of the outdoor unit.

  • Repeated thermal variations between summer and winter.

So we have:

  1. Completely discharged the remaining refrigerant.

  2. Cleaned and re-silvered the pipe section.

  3. Performed a 30 minute nitrogen pressure test to confirm leak tightness.

  4. Pulled a complete vacuum on the system.

  5. Recharged with the exact amount of R-410A according to the Fujitsu manufacturer's nameplate.

Step 2: Cleaning and optimizing the condenser

Since the condenser was installed on a balcony, it was accumulating dust, leaves, and even some moisture. We carefully cleaned the coil fins with a non-corrosive product, then rinsed with fresh water to restore better air circulation .
We also have:

  • Readjusted the position of the unit to ensure sufficient distance from the guardrail .

  • Checked the insulation of the refrigeration pipes and replaced a damaged section.

  • Resealed the wall entrances to prevent any water infiltration.

Step 3: Performance testing and final validation

Once the system was recharged and clean, we restarted the Fujitsu heat pump in cooling mode. The results were immediate:

  • The indoor air reached 16°C at the outlet after only 8 minutes.

  • The working pressures were in perfect agreement with the manufacturer's nominal values.

  • The noise level of the outdoor unit was stable and vibration-free.

We concluded our intervention by explaining to the client the importance of annual maintenance for heat pumps installed in urban areas, particularly on balconies where dust and heat accumulate quickly.

Maintenance tips for wall-mounted heat pumps on balconies

  1. Clean the condenser in spring and fall to prevent clogging.

  2. Check the free space around the unit (minimum 30 cm) to ensure good ventilation.

  3. Inspect insulating pipes : Damaged insulation can affect efficiency.

  4. Schedule annual preventative maintenance —ideally before the warm season.

These simple actions help extend the life of the system and maintain optimal energy efficiency.

Result: comfort restored and customer satisfied

Thanks to our rapid response and HVAC repair expertise , the Fujitsu wall-mounted heat pump in Plateau-Mont-Royal is now working perfectly. The customer is once again enjoying efficient and quiet cooling , knowing that their system is sealed, clean, and ready to take on the Montreal summer.

AirGreen – Experts in repair and maintenance of wall-mounted heat pumps in Montreal, Laval, Longueuil, North Shore and South Shore.