An accurate diagnosis for a heat pump that was no longer blowing hot air
At AirGreen , our team was recently called to Outremont , a well-known residential area of Montreal, to work on a Midea wall-mounted heat pump that was no longer producing adequate heat in heating mode. The customer, concerned before the arrival of the cold fall weather, had noticed that despite the correct settings on the remote control, the expelled air remained lukewarm.
Our technician immediately began a series of tests to identify the source of the problem. The first step was to check the blowing temperature at the outlet of the indoor unit , using a professional infrared thermometer . The reading showed 23.5°C , a value well below what a high-performance heat pump should produce in heating mode (usually between 35 and 45°C).
Step 1: Check the refrigeration circuit and filters
After noticing insufficient air temperature, we opened the front panel to inspect the air filters . They were slightly dirty—an often overlooked detail, but one that can reduce the performance of a wall-mounted heat pump by 10 to 20%.
Next, we measured the refrigerant pressure in the circuit. The values were lower than the standards recommended by Midea for this model, which indicated a partial loss of refrigerant . A minor leak was therefore suspected.
Step 2: Leak detection and system recharge
Using an electronic leak detector , our technician located a micro-leak at the flare fitting connecting the liquid line to the outdoor unit. This type of leak, although discreet, leads to a gradual drop in energy efficiency and an excessively low blowing temperature.
We have :
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tightened the faulty fitting;
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replaced the gasket;
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performed a complete vacuum draw of the system;
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and recharged the R410A refrigerant to the manufacturer's exact specifications.
Step 3: Electronic verification and calibration of the thermal sensor
Once the leak was repaired, we restarted the heat pump in heating mode and checked the electronic signals. The evaporator temperature sensor was still showing inconsistent readings, preventing the control board from properly adjusting the compressor output. We then calibrated the sensor using a digital multimeter and a reference thermocouple.
Result: performance and comfort restored
After these adjustments, a new reading from the wall unit's outlet showed 39.2°C —a difference of more than 15 degrees from the initial measurement. The customer immediately noticed a significant improvement in room comfort .
Thanks to our intervention, the Midea heat pump has regained its original efficiency, while guaranteeing:
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optimized energy consumption ;
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increased compressor longevity ;
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and quiet and stable operation .
Why trust AirGreen for your HVAC repairs in Montreal
At AirGreen, we don't just "fix" problems: we diagnose accurately , correct them sustainably , and prevent future breakdowns . Our certified technicians work throughout Montreal, Laval, Longueuil, the North Shore, and the South Shore , on all models of Midea, Fujitsu, Gree, Sharp, Bosch, and many other heat pumps.
We use professional measuring tools (like the infrared thermometer pictured above) to ensure each device returns to its optimal thermal performance .
Maintenance tips to avoid performance drops
For owners of Midea wall-mounted heat pumps:
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Clean the filters every 4 to 6 weeks.
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Check that nothing is obstructing the fins of the outdoor unit .
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Have a complete service performed before each heating and cooling season.
Regular maintenance helps prevent leaks, sensor errors, and circuit board failures—common problems we encounter every week in Montreal and on the North Shore.
In conclusion, this Midea heat pump repair in Outremont perfectly illustrates the expertise and rigor of our team. At AirGreen , each intervention is an opportunity to give our customers immediate comfort , maximum energy efficiency , and the peace of mind that comes with a healthy HVAC system.