A precise diagnosis on a roof in Saint-Lambert
At AirGreen , we regularly work on residential and commercial HVAC systems in the Saint-Lambert area, on the South Shore of Montreal . Recently, our technical team was called out regarding a performance issue with a Midea air conditioner installed on the roof of a commercial building. The client reported that the system was no longer cooling the offices effectively, even after several restarts.
Upon arrival, we found that the outdoor condenser was partially disassembled and several signs of wear were visible: dirty condenser fins, noisy fan motor , and most importantly, an oxidized control board .
Inspection and in-depth diagnosis
Our technicians first carried out a complete electrical check :
-
Continuity testing of power wires and internal connections;
-
Checking the starter relay and capacitor;
-
Voltage measurement at compressor and fan motor.
The measured values indicated an intermittent overvoltage , a sign of a faulty starter relay . We also noticed advanced corrosion on the exposed electrical contacts, probably due to moisture accumulated on the roof.
After a pressure test on the refrigeration circuit, no leaks of R-410A refrigerant were detected, which confirmed that the fault was originating from the electrical system rather than the refrigeration circuit.
Intervention and recommissioning
Our specialists have replaced:
-
The starter relay is faulty;
-
The motor capacitor ;
-
A section of wiring damaged by heat.
We then cleaned the condenser coils with a low-pressure biodegradable product to restore the system's thermal efficiency. The fan motor , whose bearings were already showing signs of play, was greased and hot-tested.
Once everything was reassembled, we turned the system back on. After 15 minutes of observation, the Midea air conditioner was operating at full capacity again, with a stable blower temperature of 11°C and a compressor amperage perfectly in line with the manufacturer's specifications.
AirGreen Expertise and Reliability
This type of intervention clearly illustrates the value of regular maintenance to extend the life of the Midea, Fujitsu, Gree or Zephyr air conditioners that we install and maintain throughout Greater Montreal .
Our certified technicians always ensure:
-
To respect Midea diagnostic protocols;
-
To secure electrical connections with heat shrink tubing;
-
To carry out functional tests in air conditioning and heating mode (for heat pumps).
Thanks to this rigorous approach, the client was able to regain optimal interior comfort without having to replace the entire unit.
AirGreen's advice to avoid this type of breakdown
An air conditioner, especially one located on a rooftop or balcony, is exposed to extreme conditions: heat, cold, rain, and dirt. To limit the risk of a power outage like the one encountered in Saint-Lambert, we recommend:
-
Annual preventive maintenance before the hot season;
-
A spring cleaning of the condenser ;
-
A check of the wiring to avoid corrosion;
-
A check of the refrigerant level and static pressure;
-
A capacitor test every 2 to 3 years.
These simple actions ensure the longevity of your system and significantly reduce your repair costs.
A complete service on the South Shore and beyond
At AirGreen , we cover the entire Greater Montreal area, including Longueuil, Brossard, Sainte-Julie, Laval, the North Shore and the South Shore .
Whether you own a Midea wall-mounted air conditioner , a Fujitsu heat pump , or a Bosch central system , our team has the genuine parts and electronic diagnostic tools needed to bring your equipment back to life.
We work on both residential units and commercial rooftop installations, like the one repaired here in Saint-Lambert .
In summary , this Midea air conditioner repair illustrates our know-how: rigorous analysis , targeted replacement of components , and rapid return to service guaranteeing performance and reliability.