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Réparation d’une thermopompe murale Fujitsu à Sainte-Thérèse
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Repair of a Fujitsu wall-mounted heat pump in Sainte-Thérèse

A service call on a flat roof on the North Shore

At AirGreen , we are often called upon to work on wall-mounted heat pumps installed on the flat roofs of residential and commercial buildings. These installations, which are very common in areas like Sainte-Thérèse , require special attention due to their direct exposure to the elements and temperature variations.

During this intervention, our team was contacted for a complete breakdown of a Fujitsu heat pump , installed on a roof covered with bituminous gravel. The outdoor unit no longer started, despite the control of the indoor thermostat.

Diagnosis: An inactive compressor and an electrical power supply problem

Upon our arrival, we carried out a complete analysis of the HVAC circuit .
The first observations:

  • The Fujitsu outdoor unit fan was not spinning.

  • No response from the compressor , even after several restart attempts.

  • The supply voltage was missing at the condenser terminal block.

While tracing the wiring, our technicians discovered a power problem at the roof circuit breaker : the electrical box had suffered water infiltration, causing a connector to oxidize . This type of failure is common on rooftop installations that are poorly protected against moisture and frost.

Repair steps completed

Our specialists undertook a complete and safe repair:

  1. Main power cut to ensure site safety.

  2. Replacement of the circuit breaker and complete cleaning of the electrical compartment.

  3. Checking the wiring between the Fujitsu condenser and the indoor unit to ensure stable communication.

  4. Restart under supervision , with measurement of voltages and currents to validate the correct operation of the compressor.

  5. Checking refrigerant pressures to ensure the system was leak-free.

  6. Checking the indoor blown air temperature to confirm the performance of the thermodynamic cycle.

After these steps, the heat pump resumed normal operation with an excellent level of performance.

Result: restored performance and future prevention

Thanks to this intervention, the client regained thermal comfort in their interior spaces immediately after the visit. The Fujitsu unit demonstrated perfect stability of pressures and temperatures , confirming that the problem was solely due to the power supply.

In order to avoid any recurrence, we have:

  • Installed a sealed, raised circuit breaker box to prevent rainwater or melted snow from entering.

  • Recommended routine spring maintenance to clean coils and check electrical connections.

  • Recommended to protect exposed cables with UV sheathing to extend their life.

The particularities of a roof installation

HVAC systems installed on flat roofs of residential buildings present several challenges:

  • Accumulation of water or snow around support bases.

  • Vibrations amplified by the roof structure.

  • Direct heat from the sun in summer, which can accelerate the aging of components.

This is why at AirGreen , we always favor raised supports, good air clearance and suitable mechanical protections when installing or repairing rooftop units.

AirGreen Expertise: The Difference in the Field

Fujitsu heat pumps, renowned for their energy efficiency, are among the most efficient on the market. However, they require precise calibration and maintenance to maintain their performance.

By choosing AirGreen, you benefit from:

  • Certified local expertise for all Fujitsu, Midea, Gree, Sharp, and Goodman models.

  • A rapid and documented diagnosis after each intervention.

  • A secure intervention , compliant with the standards of the Canadian Electrical Code and the Quebec Mechanical Code.

Our technicians travel throughout Montreal, Laval, Longueuil, the North Shore and the South Shore , to offer professional and lasting service.

Practical Tips for Rooftop Unit Owners

  • Visually inspect your equipment each spring for rust, damaged cables, or deformation.

  • Avoid storing objects around outdoor units : poor air circulation can reduce efficiency by 30%.

  • Plan a complete maintenance before the warm season and before winter , especially for collective buildings.

These simple steps help extend the life of your heat pump while maintaining optimal performance.

Conclusion

This Fujitsu wall-mounted heat pump repair in Sainte-Thérèse once again demonstrates the importance of preventative maintenance, especially for installations located on exposed flat roofs. Thanks to our intervention, the system has regained its reliability and efficiency, guaranteeing constant comfort for the occupants.

AirGreen – Your HVAC partner in Montreal, Laval, Longueuil, North Shore and South Shore.
Experts in the repair, maintenance and installation of Fujitsu wall-mounted heat pumps , we offer fast, durable solutions that meet the highest market standards.