Accurate diagnosis and rapid repair of a Gree outdoor unit in the middle of a Montreal winter
At AirGreen , we know that HVAC system breakdowns often occur at the most inopportune times—especially during cold January evenings. During this service call in Rosemont–La Petite-Patrie , our team was dispatched to resolve a Gree heat pump that was refusing to start properly.
Context of the intervention
The client contacted us after noticing that their outdoor unit was no longer turning on, even when the heating request was active. The installation involved a medium-capacity Gree wall-mounted heat pump , used to heat a brick duplex in Montreal.
Despite the sub-zero temperatures, our certified technician came out in the evening to perform a complete diagnosis on the narrow balcony where the unit was installed.
Inspection and initial diagnosis
Upon arrival at the scene, several elements immediately caught our attention:
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Frost buildup on the rear case of the unit, indicating a faulty defrost cycle .
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Unusual noises when trying to start the compressor.
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Abnormal pressures on the service pressure gauges , suggesting an imbalance in the refrigeration circuit.
Our team began by checking the refrigerant pressures , the proper functioning of the four-way valves, and the control signal sent by the internal electronic board. Initial measurements revealed a partial loss of refrigerant charge , probably caused by a microleak on a poorly crimped fitting.
Steps of repair
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Nitrogen leak test to confirm the presence of a leak: a slight drop in pressure was detected after a few minutes.
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Repair of the faulty connection and tightening with checking using an electronic leak detector.
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Complete vacuuming of the system using a professional pump (visible in the photo).
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Recharge with R-410A refrigerant , according to Gree manufacturer's specifications.
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Soft restart of the unit and control of high and low pressures.
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Defrost cycle verification : successful activation after simulating cold conditions.
Final result
After restarting, the Gree heat pump returned to normal performance:
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Constant hot air distributed inside the accommodation.
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Balanced and stable pressures .
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No abnormal noise or excessive vibration.
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The automatic defrost cycle was now working perfectly.
The relieved customer was able to notice a clear improvement in thermal comfort immediately after the intervention.
Technical lessons and recommendations
This type of incident is common in installations in cramped outdoor spaces, such as Montreal balconies. Direct exposure to cold and humidity can accentuate micro-leaks at the connections.
At AirGreen , we recommend:
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Annual preventive maintenance in spring or fall.
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Checking the refrigerant level before winter.
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Cleaning the coil and fan to optimize defrosting.
These simple actions will extend the life of your system while ensuring optimal energy efficiency.
AirGreen Expertise
Our specialized technicians are experts in all Gree ranges, whether wall-mounted , MultiZone or VRF models. Thanks to our advanced diagnostic instruments and our experience with local conditions in Montreal , Laval , Longueuil , North Shore and South Shore , we guarantee a fast, lasting intervention that complies with manufacturer standards .
By choosing AirGreen, you not only benefit from reliable repair, but also from service focused on the long-term performance of your HVAC system.
Comfort restored, efficiency regained — even in the heart of Montreal winter.