An emergency in the middle of winter: a heat pump stopped in the snow
The Quebec winter leaves no room for error for heating systems. One February morning in Lachine , we were called by a customer whose Gree wall-mounted heat pump had stopped working in the middle of a storm. The outdoor compressor would no longer start, leaving the home in the freezing cold despite repeated attempts to restart it.
Background and initial inspection
When we arrived, the scene was typically wintery: snow accumulating around the condenser , temperatures below -15°C and restricted access to the terrace. The outdoor unit, mounted on a raised stand, showed signs of humidity and thick frost on the refrigeration lines.
Our initial checks have revealed:
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Power supply correct , but no response from the starter relay.
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Traces of moisture on the control box.
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Abnormal refrigerant circuit pressure , a sign of possible obstruction due to cold.
Diagnosis: Control board affected by humidity
After a thorough test using our digital manifold , we confirmed that the problem was with the main circuit board : moisture had seeped into the enclosure, causing a minor short circuit on the control section. This situation is common when the cover is not perfectly sealed or the cable routing is not properly sealed.
AirGreen intervention: repair, protection and restart
At AirGreen, we know that in winter, every minute counts. Here are the steps of our intervention in Lachine:
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Complete power cut and securing of the workstation.
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Removal of the electronic card and controlled drying in a mobile hot air workshop.
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Check wiring and connections before reinstallation.
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Added a dielectric sealant to prevent future infiltration.
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Restart the system and fully test the heating and defrost cycles.
We also cleaned the outdoor coils to remove ice buildup and then rebalanced the R-32 refrigerant charge after checking the suction and discharge pressures.
Result: restored comfort and optimized efficiency
As soon as the power was turned back on, the Gree heat pump resumed normal operation. The automatic defrost cycle started correctly, and the hot air flow quickly brought the indoor temperature back to a comfortable level.
The relieved customer highlighted the speed of our intervention despite the extreme weather conditions. We took advantage of the visit to remind him of the importance of preventative winter maintenance , including:
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clear snow around the outdoor unit;
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check that the defrost drain is flowing properly;
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prevent ice from building up on refrigeration pipes.
The Importance of Prevention for HVAC Systems in Cold Climates
Gree wall-mounted heat pumps are designed to provide reliable performance down to -25°C, but their durability depends largely on maintenance. Our technicians recommend:
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a complete annual inspection before winter;
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cleaning the coils and filters at the start of each season;
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and the addition of a voltage protector to secure sensitive electronics.
This preventative approach not only prevents breakdowns, but extends equipment life while maintaining optimal energy efficiency.
AirGreen: a fast and technical service for all of Greater Montreal
Whether you are in Montreal, Laval, Longueuil, on the North Shore or the South Shore , our team is ready to intervene, even in the middle of a storm. Every service call is handled with the same rigor: accurate diagnosis, lasting repairs and total transparency .
The intervention in Lachine demonstrates our commitment to maintaining the comfort of Montreal homes, even in the most extreme conditions.