A Mr. Slim heat pump in distress in a hard-to-reach corner
Recently, our AirGreen team was called to repair a Mitsubishi Mr. Slim wall-mounted heat pump in a charming duplex in Montreal's Outremont neighborhood. The outdoor unit, installed in a tight space between two brick walls, was experiencing poor heating performance and an abnormal noise when turned on . These symptoms, often overlooked by homeowners, can signal impending fan failure or a refrigerant pressure issue.
Diagnosis: A confined space and an overheating device
Upon our arrival, we noticed several challenges:
-
The unit was installed very close to the walls , limiting air circulation.
-
Debris and dust had accumulated on the condenser.
-
The outside fan was struggling to maintain the correct pressure.
Using our measuring instruments, we observed a slightly lower than normal refrigerant pressure , which indicated a microleak in the circuit . The compressor, which was overheating for a long time, was also at risk of damage.
Technical intervention: cleaning, detection and recharging
Our certified technicians proceeded in stages:
-
Thorough cleaning of the condenser using a gentle jet and a specialized biodegradable product for aluminum surfaces.
-
Nitrogen test to locate the leak. It came from a cracked solder joint on a copper junction, a common weak point in older installations.
-
Repair of the solder and checking for leaks .
-
Recharge of R410A refrigerant according to Mitsubishi specifications.
-
Complete performance test with temperature measurement and differential pressure measurement.
Everything was carried out in compliance with environmental standards and safety procedures specific to our industry.
Result: efficiency restored and comfort restored
Once the heat pump was restarted, tests revealed:
-
Airflow restored to 100% .
-
Optimal thermal efficiency , with an interior/exterior temperature delta in line with Mitsubishi standards.
-
A reduction in fan noise , evidence of a newly balanced engine.
We also advised the customer to leave a minimum clearance of 30 cm around the unit to improve ventilation and extend the life of the compressor.
The importance of regular maintenance
Mitsubishi Mr. Slim wall-mounted heat pumps are renowned for their reliability, but they require annual maintenance to avoid this type of failure:
-
Cleaning the condenser and evaporator.
-
Checking the refrigerant charge.
-
Electrical and mechanical inspection of the motor and boards.
-
Automatic drainage and defrost control.
Regular maintenance by a qualified team like AirGreen not only ensures quiet and efficient operation , but also prevents costly repairs in the long run.
Our Mitsubishi expertise in Montreal and throughout the metropolitan area
At AirGreen , we are authorized specialists in Mitsubishi Electric systems . Whether for installation, diagnosis, or repair, our teams respond quickly in Montreal, Laval, Longueuil, the North Shore, and the South Shore . Every service call is handled with rigor, transparency, and a deep respect for our customers' comfort.
In the case of this intervention in Outremont, our client was able to regain immediate comfort , reduced energy consumption , and above all the peace of mind provided by a perfectly adjusted HVAC system.