A silent but inefficient heat pump: our detailed diagnosis
At AirGreen , we frequently receive calls from customers who notice that their heat pump is running without actually cooling or heating . This is exactly what happened during this service call in Saint-Bruno , on the South Shore of Montreal.
The customer contacted us after noticing that their wall-mounted Elio unit was no longer able to maintain a comfortable temperature, despite an external compressor apparently being running.
Initial inspection: a clean but inefficient device
On site, our technician first carried out a complete inspection of the Elio outdoor unit , installed at the base of the residence's wall, on a well-prepared gravel bed. The installation was visibly recent and compliant with standards - stable support, sufficient clearance and protected pipes .
However, a quick temperature test using an infrared thermometer revealed lukewarm air output in air conditioning mode , an early indicator of a problem in the refrigeration cycle .
Step 1: Check the filters and coils
Before proceeding further, we inspected the indoor unit. The filters were clean and the evaporator coils were free of excessive dust. No frost or obstructions were visible.
➡️ Conclusion : The problem was not due to a lack of maintenance or a blockage of airflow.
Step 2: Analysis of the refrigeration circuit
We then measured the pressure of the R410A refrigerant on the outdoor condenser. Result: abnormally low pressure . This clearly pointed to a minor leak .
Using an electronic leak detector , we inspected all the fittings—especially those on the flare pipes .
The detector reacted near the low-pressure connection, where the copper fitting had lost a slight seal due to micro-vibrations.
Step 3: Repair and recommission the system
Our technicians proceeded as follows:
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Tightening the flare fitting and replacing the gasket .
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Test under nitrogen to ensure no leaks remain.
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Complete vacuum for 45 minutes to remove any residual moisture.
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Recharge the system with the exact amount of refrigerant recommended by the manufacturer Elio.
After restarting, the difference was immediate: the blown air went from 11°C to 6°C , a performance perfectly in line with expectations for a heat pump in air conditioning mode.
Step 4: Additional checks
To ensure lasting performance, we also have:
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Cleaned the outdoor condenser at low pressure to remove dust and pollen.
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Checked the interior temperature sensor , often responsible for irregular on/off cycles.
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Tested the automatic defrosting of the system to ensure proper operation during cold seasons.
Everything turned out to be functional. We then explained to the customer the warning signs of a minor leak and the importance of having the system inspected at least once a year .
Final result: restored efficiency and immediate comfort
At the end of the intervention, the Elio heat pump was once again providing rapid, stable and quiet cooling .
The customer noticed a significant improvement in the room temperature within the first few minutes.
Refrigerant pressures and blowing temperatures were within the recommended nominal ranges , ensuring optimal energy consumption .
What we learned from this intervention
This repair illustrates a typical case encountered in the field:
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A compliant installation , but a progressive micro-leak due to vibrations.
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A lack of thermal efficiency without noise or obvious error code.
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An accurate diagnosis thanks to our instruments and the field experience of our HVAC technicians.
At AirGreen , our priority is always to ensure customer comfort while extending the life of the equipment .
We work on all major brands: Elio, Midea, Fujitsu, Sharp, Gree, Trane, Mitsubishi, Bosch, Lennox and many others — throughout Montreal, Laval, the North Shore and the South Shore .
Advice to the owner
To avoid future inconvenience:
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Have your system checked every spring or fall before busy seasons.
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Avoid blocking the air vent of the outdoor condenser.
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Clean the internal filters regularly (at least once a month).
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Immediately report any abnormal noise, drop in performance or water leaks .
A well-maintained heat pump offers up to 30% additional energy savings and a lifespan that can exceed 15 years .
Conclusion
This intervention in Saint-Bruno once again demonstrates the rigor and know-how of AirGreen , specialist in the repair of wall-mounted heat pumps throughout the greater metropolitan area.
Thanks to rapid detection, clean repair and precise reloading, customer comfort was fully restored .