Roof intervention: a precise and technical service call signed AirGreen
When a client in Sainte-Thérèse , on the North Shore of Montreal , contacted us about a problem with a Gree wall-mounted heat pump that was no longer producing enough heat, our team quickly planned an intervention. Installed on the roof of a residential building, this outdoor unit required a meticulous and safe diagnosis , given its direct exposure to cold and bad weather.
Background to the breakdown: declining thermal efficiency in the middle of winter
The customer reported that, for several days, the heat pump seemed to be running without interruption, but the indoor temperature no longer rose above 19°C .
At this time of year, with outside temperatures around -5°C , a drop in performance can reveal several possible causes:
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Partial loss of refrigerant,
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Obstruction of the external coil,
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Temperature sensor or reversing valve fault,
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Communication problem between electronic cards.
First step: visual inspection and pressure diagnosis
On the roof, our technician immediately noticed a buildup of dust and fine debris on the condenser fins, reducing heat exchange capacity.
After connecting the pressure gauges and measuring the system pressures , he noticed a slight undercharge of R-410A refrigerant , suggesting a microleak somewhere in the system.
Precise location of the leak: AirGreen method
To confirm the hypothesis, we used an electronic leak detector combined with a nitrogen test .
Result: a small leak detected at the level of the brazed joint on the liquid line .
This area, directly exposed to thermal variations, had been undergoing repeated expansion and contraction for a long time, resulting in a micro-crack almost invisible to the naked eye.
Complete repair and system recharge
The intervention took place in several rigorous stages:
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Purging the circuit and recovering the remaining refrigerant.
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Rework of the soldering with a torch , applying a protective flux to prevent oxidation.
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Leak test under nitrogen for 30 minutes, with no pressure drop observed.
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Complete vacuum to -29 inHg to remove all traces of moisture.
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Exact recharge with R-410A refrigerant , according to the charge prescribed by the Gree manufacturer.
We also took advantage of the intervention to clean the condenser with warm water and tighten the electrical connections in the control box.
Results: optimal performance restored
After restarting, the heat pump quickly demonstrated impeccable thermal performance :
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Stable discharge pressure,
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Interior blowing at 47°C ,
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Ambient temperature rising rapidly.
The client, impressed by the precision of the intervention, noted an immediate improvement in the comfort of his home.
The compressor noise had also softened, evidence that the system was once again operating within its ideal parameters.
Recommended preventive maintenance
Before leaving the premises, our technician advised the customer:
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Annual cleaning of the outdoor coil to prevent the accumulation of dust and pollen;
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A pressure check at the start of each season;
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An insulation check of refrigeration lines , especially for units installed on roofs exposed to wind.
At AirGreen , we make it a point to train our customers on best maintenance practices to extend the life of their HVAC systems.
Why choose AirGreen for your heat pump repairs in Montreal and on the North Shore
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Certified technicians for brands Gree, Midea, Fujitsu, Sharp, Goodman, Trane, and more;
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High-precision diagnostic equipment (electronic detectors, digital probes, connected pressure gauges);
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Fast and secure intervention , even on roof installations;
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Full warranty on repairs and replaced parts.
Conclusion
This Gree wall-mounted heat pump repair in Sainte-Thérèse illustrates the rigor and technicality of our interventions.
By restoring the refrigeration circuit's tightness and ensuring perfect refrigerant calibration, AirGreen restored the system to full efficiency—guaranteeing stable, quiet, and energy-efficient heating for the remainder of the cold season.
At AirGreen, we combine technical expertise, precision and passion for the job , so that every home in Greater Montreal, Laval, Longueuil, the North Shore and the South Shore can find comfort, whatever the outside temperature.
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