A service call on the roof of a building: diagnosing a faulty Zephyr unit
At AirGreen , we regularly receive calls for Zephyr HVAC systems installed on the roofs of commercial or multi-family buildings. This time, our team went to Sainte-Julie , on the South Shore, to diagnose a Zephyr wall-mounted heat pump that was no longer producing cold despite an outdoor fan being on.
The context of the intervention
The client, a building manager, had noticed for several days that the system was no longer able to maintain a comfortable indoor temperature. The outdoor unit, although apparently functional, was not generating any effective cooling. We therefore dispatched one of our certified technicians to perform a complete on-site diagnosis .
Visual inspection and initial findings
As soon as the panel was opened, several clues were visible:
-
Dust accumulation on the condenser coil.
-
Internal wiring slightly oxidized by exposure to sunlight and humidity.
-
Obviously abnormal refrigerant pressures.
The technician immediately installed his dual gauge manifold and connected a digital multimeter to measure the supply voltage and continuity of the electrical components.
Precise diagnosis: partial loss of refrigerant charge
Pressure readings revealed a marked imbalance between high and low pressure , indicating a refrigerant leak . The compressor, although functional, was running at no load and was at risk of long-term overheating. After a continuity check, the start capacitor also showed slight weakening (values below Zephyr specifications).
Steps of repair
Here's how our technician went about getting the unit back in perfect condition:
-
Recovery of residual gas in order to comply with environmental standards.
-
Leak detection using an electronic detector and a foam solution: the leak came from a slightly loose flare fitting .
-
Tightening and refurbishment of the seal with replacement of the flare.
-
Nitrogen leak test under pressure for 20 minutes — no leaks detected.
-
Complete vacuum for 40 minutes at -30 inHg.
-
Recharge the system with R410A refrigerant according to the manufacturer's specifications.
-
Replacing the capacitor and checking the electrical connections.
Final checks
Once the system was recharged and closed, the measurements indicated perfectly balanced pressures. The superheating and subcooling rates were in line with Zephyr standards, indicating optimal operation. After a few minutes, the interior air was blowing at a temperature of 12°C—proof that comfort had been fully restored.
Results and advice to the client
The manager was pleased to see that the system was back to its original power. We recommended:
-
Cleaning the condenser twice a year to prevent fouling.
-
A preventive pressure check before each summer season.
-
Adding a UV protective cover on top of the compressor to extend the life of the wiring and electronic components.
AirGreen Expertise: The Difference of a Professional Service
This type of intervention highlights the importance of rigorous maintenance on residential and commercial HVAC systems. At AirGreen, our technicians have all the necessary equipment to perform:
-
Accurate diagnostics (electrical, refrigeration and electronic).
-
Fast and durable repairs , compliant with environmental standards.
-
Personalized monitoring to guarantee the reliability of installations, whether in Montreal, Laval, Longueuil or on the North Shore and the South Shore.
A high-performance Zephyr system again
At the end of the intervention, the Zephyr heat pump was operating quietly, without vibrations or whistling. The pressure was stable and the indoor temperature was comfortable again. Thanks to a quick and methodical intervention , the customer avoided a complete compressor failure and a costly replacement.
In summary , this repair demonstrates our expertise in leak diagnosis, refrigerant recharging and maintenance of Zephyr heat pumps . Every day, our teams operate in the greater Montreal area to ensure the comfort, performance and peace of mind of our customers.