Technical intervention on a residential roof: efficiency and precision at the heart of the AirGreen service
At AirGreen , we are often called upon to intervene in a variety of contexts, ranging from single-family homes to residential buildings in Montreal. This time, our team went to the Côte-des-Neiges–Notre-Dame-de-Grâce neighborhood, for a repair of a Fujitsu central heat pump installed on the roof of an apartment building.
The customer reported a complete heating shutdown , despite the indoor fan being operational. The system was blowing air at room temperature without producing heat. A typical case of a refrigeration circuit failure or a faulty electrical component .
Step 1 – In-depth diagnosis of the heat pump
Upon our arrival, our technicians conducted a complete visual inspection of the outdoor condenser , located on the flat roof of the building. The failure occurred following a restart after a period of freezing , a common scenario in Montreal at the end of winter.
Initial findings:
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No active error lights on the main board.
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The compressor would not start , although the supply voltage was present.
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The fans were responding normally.
We therefore directed the diagnosis towards an anomaly of the compressor start relay or a defective control board .
Step 2 – Electrical Check and Voltage Measurements
Using our professional multimeter, we measured:
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Supply voltage: 240 V stable.
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Compressor control: intermittent.
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Winding resistance: in accordance with Fujitsu values.
The analysis made it possible to locate a faulty thermal relay , preventing the compressor from starting. The relay, slightly oxidized due to exposure to cold and humidity, was no longer closing correctly.
Step 3 – Repair and Replacement of Components
Our team has undertaken a complete overhaul :
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Removing the electrical compartment cover .
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Cleaning the connectors and replacing the thermal relay with an original Fujitsu part.
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Check the start and run capacitors to ensure stable current.
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Checking the internal wiring to eliminate any traces of potential short circuits.
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Power up and complete system test .
Once the repair was completed, the compressor restarted normally. The heat pump regained its heating capacity, delivering a stable 42°C warm air to the indoor unit outlet.
Step 4 – Optimization and recommendations to the client
As with every AirGreen service call , our service doesn't stop at simple repairs. We also have:
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Cleaned the electrical compartment to prevent future infiltration.
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Checked the R-410A refrigerant charge : no imbalance detected.
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Customer advised to perform a complete preventative maintenance in spring , in order to extend the life of the compressor.
We've also added programmable freeze protection to prevent the unit from restarting too early during mild winter periods.
AirGreen Expertise: Safety, Performance and Sustainability
This Fujitsu central heat pump repair in Côte-des-Neiges is a good illustration of the thoroughness of our work.
Our certified technicians follow a precise protocol, inspired by the manufacturer's recommendations, in order to guarantee:
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A complete analysis before replacing parts .
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Safe interventions on roofs thanks to compliant fall protection equipment.
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Detailed internal documentation of each intervention.
Thanks to this approach, AirGreen ensures long-lasting reliability of the HVAC system, while optimizing its energy performance.
The result: restored comfort, a heat pump ready for the season
After our visit, the client found stable and efficient heating throughout the building.
The Fujitsu heat pump is now ready to withstand Montreal's temperature variations, while maintaining optimal energy efficiency.
AirGreen remains your trusted partner for all your HVAC repair needs , whether you are in Montreal, Laval, Longueuil, on the North Shore or the South Shore .