A service call for a heat pump that no longer heats
At AirGreen , we recently received an emergency call from a customer living in Boisbriand , on the North Shore of Montreal , whose Zephyr wall-mounted heat pump was refusing to provide heat despite the proper settings. The outdoor unit, securely installed on the floor along the side wall of the house, appeared visually intact, but was no longer starting.
This type of problem is typical of the transition periods between winter and spring, where humidity and salt residue can affect the electronic components of a heat pump exposed to the elements.
Technical diagnosis: an electronic card is the cause
Our technician began with a complete electrical diagnosis of the Zephyr heat pump. The goal: to determine whether the fault was caused by a power supply fault, a mechanical part (fan or compressor), or a control component.
Checks carried out:
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Input voltage measured at 240 volts: compliant.
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Internal fuses : intact.
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Start capacitor : Tested OK.
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Indoor unit control : signal sent but not received.
After a thorough inspection of the main module, diagnostics revealed a faulty electronic board —specifically, a burnt-out relay on the compressor control section. This type of failure is often caused by a power surge or moisture infiltration.
Card Replacement and System Calibration
We carried out a complete replacement of the Zephyr control board , an original part supplied by our certified warehouse. Once the new board was installed, the technician:
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Checked model/series compatibility codes ;
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Reprogrammed the defrost settings ;
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Synchronized the indoor and outdoor unit via electronic pairing procedure (pairing).
Once restarted, the heat pump immediately resumed its normal cycle. The compressor kicked in, the fan ran quietly, and warm air flow was restored throughout the house.
The customer was able to see, within minutes, the difference in temperature and the restored stability of the system.
Common causes of electronic failures in wall-mounted heat pumps
Zephyr heat pumps are known for their reliability and good value. However, like all HVAC systems, they can be vulnerable to certain environmental factors:
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Water or condensation infiltration into the electrical box.
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Electrical surges caused by thunderstorms or network fluctuations.
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Accumulation of debris or insects near the electronic module.
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Natural aging of printed circuits after several thermal cycles.
At AirGreen, we strongly recommend installing an HVAC surge protector to protect the control board and sensitive components of your unit.
Prevention and maintenance: essential actions
To prevent similar breakdowns, our technicians advise all owners of wall-mounted heat pumps:
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Clean the outdoor condenser at least twice a year, especially after winter.
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Ensure proper drainage of the condensate pipe.
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Check the clearance around the outdoor unit (minimum 30 cm).
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Schedule an annual inspection by an AirGreen certified technician.
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Install electrical protection if the main panel is old or prone to fluctuations.
These simple steps can extend the life of your Zephyr system and avoid costly card replacements.
AirGreen expertise: reliability, speed and transparency
Our AirGreen team covers the entire North Shore, Montreal, Laval and the South Shore with fast and meticulous HVAC repair service.
Each intervention is preceded by a complete diagnosis , accompanied by a clear and straightforward quote.
With our local stock of genuine Zephyr, Gree, Fujitsu, Midea, Sharp and Goodman parts , we often provide same-day repairs .
In Boisbriand, our technician not only replaced the faulty circuit board, but also added an additional seal around the electrical box to prevent future leaks. This attention to detail is part of AirGreen's DNA: we repair permanently, not temporarily.
Comfort restored, a satisfied customer
A few hours after our intervention, the client confirmed that the indoor temperature had returned to a stable and comfortable level, even on chilly March nights. The Zephyr heat pump is now operating at full efficiency, with optimized power consumption.
This case demonstrates once again that proactive maintenance and professional diagnosis can save a unit years of service.
AirGreen – Experts in repairing Zephyr wall-mounted heat pumps in Boisbriand and throughout the North Shore.