A service call under the sun: a broken heat pump reveals a ventilation problem
At AirGreen , we frequently receive calls related to central heat pump breakdowns during the first warm days of spring. This time, our team went to Sainte-Thérèse , on the North Shore of Montreal , to work on a Midea central heat pump that was no longer producing cold.
Initial diagnosis: a half-open system and a stopped fan
Upon arriving on site, we found the outdoor condenser completely open, the panels removed , and the main fan stopped . The owner had noticed an unusual noise followed by a sudden shutdown of the system . Quickly, our technician performed:
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a complete visual check of the outdoor unit;
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a power supply test of the control circuits;
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and a fan motor continuity check .
The finding: the condenser fan motor had overheated following an accumulation of debris and an imbalance in the blades caused by a slight impact.
Step 1: Secure and thoroughly clean the condenser
First and foremost, it was essential to ensure the safety of the intervention. The power supply was cut off at the main circuit breaker . Then:
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We removed the side panels and thoroughly cleaned the condensing coil using a biodegradable product.
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The fan blades were disassembled, cleaned and inspected for any cracks or deformation.
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The interior of the compartment was vacuumed and dried , removing dust and insects accumulated around the electronic boards.
Step 2: Fan Motor Replacement and Rotation Test
After cleaning, we replaced the original Midea fan motor , a variable speed model compatible with the 36,000 BTU central series .
The wiring was redone according to the factory color codes , checking each connection on the main board and the power module .
We then ran a manual spin test , then a live electrical test : the fan started spinning silently again, with a steady airflow.
Step 3: Check refrigerant pressure and calibrate the system
Replacing an engine always requires a check of the complete thermodynamic cycle . We connected our digital pressure gauges and observed:
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High Side Pressure: 265 psi
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Low side pressure: 120 psi
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Overheating temperature: 9°C
Values perfectly within the standard for a Midea system charged with R410A . No leaks were detected.
Step 4: Calibration and final reassembly
Once the tests are completed, we have:
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Reinstalled the side and top panels ;
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Cleaned the interior air filter of the central module;
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Reset the wall thermostat and reconfigured the customer's time slots.
We also checked the communication between the indoor and outdoor boards , ensuring perfect synchronization of the hot/cold cycles.
Result: performance restored and comfort restored
After a full hour of operation, the interior temperature had dropped from 26°C to 22°C , with constant airflow and minimal noise .
The customer was impressed with the speed of the return to service and took advantage of our seasonal maintenance advice :
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Clean the condenser in spring;
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Keep at least 60 cm free around the unit;
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Never attempt to force the fan when it is stopped.
Why this repair illustrates AirGreen know-how
This type of intervention requires in-depth knowledge of Midea electronic circuits and thermal management .
Our certified technicians have a complete inventory of original parts and digital diagnostic equipment allowing them to intervene quickly, without improvisation.
With this approach, we avoided costly compressor replacement and extended the system's life by several years .
In conclusion
This Midea central heat pump repair in Sainte-Thérèse perfectly demonstrates our commitment to quality, precision and durability .
At AirGreen , we operate throughout Greater Montreal — Montreal, Laval, Longueuil, the North Shore and the South Shore — to offer HVAC services that combine efficiency, reliability and technical expertise .