A service call in the heart of winter on the South Shore
On a cold January morning in Sainte-Julie , our AirGreen team was called to work on a Maxi Air wall-mounted heat pump that was no longer heating adequately. Installed on a wall bracket on the north side of a single-family home, the outdoor unit was already showing visible signs of winter stress: ice on the ground, frost buildup on the fins, and an abnormal noise at startup.
Context of the intervention
The customer contacted us after noticing that the heat pump was blowing warm or even cold air, despite a constant heating demand. This symptom is typical of a faulty defrost circuit or a temperature sensor problem. The Maxi Air brand, although reliable, is sensitive to electronic defrost management, especially during the humid winters south of Montreal.
Technical diagnosis: between ice and electricity
Our certified technicians began with a complete diagnosis:
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Checking the defrost cycle : the heat pump was not triggering the automatic sequence.
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Temperature probe test : the outdoor probe indicated an aberrant value (-47°C), which prevented the system from recognizing the need for defrosting.
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Control module inspection : The electronic board showed signs of moisture, probably caused by condensation under the cover.
Another worrying detail: the presence of bungee cords securing a wooden protective panel above the unit. While this protection was well-intentioned, it partially blocked the flow of hot air and contributed to the buildup of ice around the compressor.
AirGreen Repair Steps
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Safe dismantling of the improvised protection to release the heat pump.
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Complete cleaning of the outdoor unit using a dry steam defroster, without damaging the fins.
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Replacement of the defective temperature sensor with an original Maxi Air part.
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Drying and cleaning of the electrical compartment , then application of an insulating varnish to protect against humidity.
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Checking R-410A refrigerant pressures to confirm circuit stability.
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Defrost cycle calibration using our proprietary diagnostic interface.
After restarting, the unit operated stably. The indoor air temperature increased from 16°C to 32°C in less than 10 minutes, restoring comfort to the home.
Personalized advice for optimal winter maintenance
At AirGreen, we know that the Quebec climate puts a strain on heating systems. After each repair, we take the time to advise our customers. In this specific case, we recommended:
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To avoid any obstruction of the air flow , even by temporary protection.
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To clear the base of the unit of ice every two weeks during periods of thaw.
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Visually check drainage pipes , especially after storms.
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Schedule annual preventative maintenance before the cold season.
AirGreen Expertise: a service designed for the climate of the South Shore
Each intervention by our team is adapted to the reality on the ground. We understand the challenges specific to residential installations in Sainte-Julie, Boucherville and Brossard , where heat pumps are often exposed to snow, wind and rapid temperature variations.
Our strength:
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Technicians specialized by brand (Tosot, Gree, Maxi Air, Fujitsu, Midea, etc.)
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Durable and guaranteed repairs
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Certified original parts
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Rapid availability for HVAC emergencies throughout the South Shore, Laval and Montreal
Final result
Thanks to our intervention, this customer's Maxi Air system is now fully operational and ready to face the rest of the winter. The repair not only restored heat, but also improved the system's energy efficiency by reducing unnecessary defrost cycles.
This experience perfectly illustrates AirGreen 's mission: to offer a fast, rigorous HVAC repair service perfectly adapted to the Quebec climate, while guaranteeing the durability and long-term comfort of each installation.