When a Fujitsu outdoor unit experiences an electrical problem
At AirGreen , we are often called upon to work on Fujitsu systems , which are renowned for their reliability, but require rigorous maintenance. This service call in Sainte-Dorothée, Laval , concerned a Fujitsu wall-mounted heat pump whose outdoor unit had stopped working after a power outage. The owner feared a problem with the compressor or electronic board.
On-site diagnosis: a localized electrical fault
Upon arrival, we conducted a thorough inspection of the outdoor condenser , securely mounted on a brick wall. The installation was clean and well ventilated, but we quickly noticed that the wall-mounted safety circuit breaker (gray box next to the unit) was no longer transmitting current. An initial check with a multimeter confirmed that there was no voltage to the unit.
After opening, we discovered internal oxidation of the circuit breaker , probably caused by moisture accumulated over the seasons. Although the Fujitsu system itself was not at fault, this connection failure prevented any start-up.
Step 1 — Secure and Log Out
Before any work was done, our technician turned off the main power supply to ensure the safety of the intervention. We then disconnected the power cable connecting the box to the condenser to check the integrity of the wiring.
Step 2 — Replacing the wall circuit breaker
A new sealed, outdoor-rated disconnect box was installed, with waterproof connectors to prevent future infiltration. We also applied a protective dielectric paste to the terminals to ensure increased contact longevity.
Step 3 — Complete System Check
Once the power was restored, we restarted the Fujitsu heat pump in both heating and cooling mode. The results were perfect:
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Balanced pressures on the two refrigerant circuits
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No leak detected at the service valve
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Compressor and fan operating without noise anomaly
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Defrost and cycle reversal fully functional
Cause analysis: humidity and exposure
This type of failure is typical of outdoor installations not protected by an awning . Moisture, rain, and frost can damage electrical components over time, even when they are initially rated to IP54. We always recommend our customers consider adding a protective cover or wall cap to extend the life of HVAC equipment.
Final result: comfort and tranquility restored
The Fujitsu system was restored to its original efficiency , and the customer was able to enjoy constant comfort again, both in heating and air conditioning.
Before we left, we also cleaned the condenser's protective mesh and tightened the wall fixings to prevent any vibration.
What to remember from this intervention
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Initial symptom: outdoor unit inoperative
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Diagnosis: No power due to oxidation of the circuit breaker
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Solution: Complete replacement of the disconnect box and checking the wiring
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Result: Fully operational and secure Fujitsu system
AirGreen tips to avoid this type of breakdown
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Have the power supply checked once a year, especially after winter.
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Install a rain and snow protection cover .
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Clean fins and filters to maintain optimal airflow.
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Schedule an annual AirGreen maintenance service , so our technicians can prevent any premature oxidation or degradation.
AirGreen: Fujitsu wall-mounted heat pump experts in Laval and throughout the North Shore
With over 15 years of experience in residential HVAC , AirGreen prides itself on providing fast, honest, and professional service. Our certified technicians work on all makes and models of wall-mounted heat pumps , including Fujitsu, Midea, Gree, Lennox, Goodman, Sharp, and Zephyr , in Montreal, Laval, Longueuil, the North Shore, and the South Shore .
Your comfort is our priority, and each intervention is carried out with attention to detail and compliance with the strictest standards in the HVAC field.