A typical service call that highlights our AirGreen expertise
At AirGreen , every HVAC repair is an opportunity to restore comfort, efficiency, and peace of mind to our customers. Recently, our team visited the Rosemont–La Petite-Patrie neighborhood of Montreal to diagnose a fault on a Mitsubishi Electric Mr. Slim wall-mounted heat pump , which uses R410A refrigerant—a reliable and efficient system, but like any appliance, it sometimes requires precise technical attention.
Initial diagnosis: an outdoor unit weakened by time and the elements
Upon arrival, we noticed that the outdoor unit, mounted on a wall bracket above ground level, showed visible signs of aging:
-
Accumulation of debris and foam under the protective shelf, restricting air circulation.
-
Light corrosion on the fan grill.
-
Wear and tear on the electrical power wiring , exposed to the elements.
The customer informed us that the heat pump had not been heating adequately for several days and that the outdoor fan was no longer starting .
Step 1: Electrical Check and Circuit Inspection
Our technicians first tested the power supply:
-
Correct voltage at the circuit breaker.
-
Weak signal from the control board.
-
Abnormal resistance in the fan motor.
The diagnosis pointed to a faulty fan motor or a faulty capacitor .
So we removed the front cover and measured the capacitor's capacitance: result — almost zero value.
The fault was indeed caused by this small component essential for starting the engine .
Step 2: Capacitor Replacement and Recommissioning
After consulting our mobile inventory, we replaced the 2.5 µF 450V capacitor with an equivalent model, approved by Mitsubishi Electric.
We also have:
-
Cleaned the front grille and the fins of the exchanger.
-
Checked the pressure of the R410A refrigerant (within standards).
-
Reattached and insulated the power cable to prevent any short circuits.
Once the new capacitor was installed, the fan started running again immediately , and the heat pump resumed its normal heating cycle.
Step 3: Prevention and maintenance advice
We explained to the client the importance of:
-
Clean the internal filters regularly (once a month).
-
Check for free air circulation around the outdoor unit.
-
Avoid the accumulation of water and debris on the protective shelf.
-
Schedule an annual inspection to maintain compressor and electronic board performance.
This type of simple maintenance often helps prevent major breakdowns and extend the life of a heat pump by several years.
Result: comfort regained and efficiency restored
Within minutes of restarting, warm air was circulating throughout the house again. The satisfied customer was impressed by the speed of the diagnosis and the clarity of our explanations.
The Mr. Slim heat pump , renowned for its reliability, has returned to peak performance—proof that even robust systems need expert maintenance to perform at their best.
Why entrust your Mitsubishi heat pump to AirGreen?
-
Mitsubishi Electric Certified Technicians
-
Genuine parts and fast service in Montreal, Laval, Longueuil, North Shore and South Shore
-
Complete on-site diagnosis , with total transparency
-
Proactive prevention to avoid costly breakdowns
-
Personalized support and after-service follow-up
At AirGreen, we make every effort to ensure your HVAC system remains efficient, quiet, and energy-efficient year-round—even in Montreal's winter conditions.
Need HVAC repair service?
Contact our team today for a fast and professional diagnosis. Your comfort deserves AirGreen quality.
SEO Keywords : Mitsubishi heat pump repair , Mr. Slim , R410A , HVAC maintenance Montreal , heating air conditioning repair Rosemont , AirGreen Laval Longueuil North Shore South Shore