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Réparation d’un climatiseur mural Tosot à Côte-des-Neiges
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Repair of a Tosot wall-mounted air conditioner in Côte-des-Neiges

When a compressor failure tests the performance of a Tosot wall-mounted air conditioner

At AirGreen , we were recently called for HVAC repair service in a residential building in Montreal's Côte-des-Neiges neighborhood. The customer contacted us after noticing that their Tosot Inverter wall-mounted air conditioner was no longer producing cold air, despite an outdoor unit that appeared to be working. This type of call is common during the summer, especially when the outdoor unit is exposed to strong sunlight and extended operating cycles.

Initial diagnosis: a system that appears functional, but ineffective

Upon our arrival, our technicians performed a complete visual inspection of the Tosot condenser , installed on a sturdy metal wall bracket, typical of Montreal balconies. The unit was well maintained and electrically powered, but the expelled air remained lukewarm.

The first tests quickly revealed:

  • A compressor that started but did not maintain adequate pressure.

  • An abnormally high discharge temperature.

  • No error signal visible on the control board.

We therefore carried out an in-depth diagnosis of the refrigeration circuit .

Step 1: Refrigerant Check and Leak Detection

Using our electronic detector, we confirmed the presence of a micro-leak of R-410A refrigerant at the base of the liquid pipe connection. This leak, although minimal, was enough to disrupt the air conditioner's thermodynamic cycle and prevent proper compression.

The probable cause: a slight mechanical vibration due to the location of the condenser, fixed on a balcony exposed to the wind.

We have :

  1. Pinpointed the leak.

  2. Performed a high temperature repair solder .

  3. Performed a complete vacuum draw of the system.

  4. Recharged the circuit according to the specifications of the manufacturer Tosot.

Step 2: Electronic control and calibration

After powering up, the compressor returned to its nominal behavior. We checked the Inverter control board , which is responsible for modulating the compressor speed. No electronic failure was detected. However, we recalibrated the communication parameters between the indoor and outdoor units to optimize the temperature response.

Step 3: Checking airflow and condensate

The indoor unit had a slightly clogged filter , which was reducing airflow. We cleaned the filter, inspected the condensate drain , and confirmed proper drainage. These steps, while simple, are critical to preventing moisture or frost buildup in the coils.

Final result: restored performance and reassured customer

Following our repairs, the Tosot Inverter air conditioner regained its full cooling capacity. The discharge and suction temperatures stabilized at optimal levels, ensuring high energy efficiency and immediate comfort in the apartment.

The relieved customer noticed a rapid and constant drop in temperature within the first hour, without excessive noise or vibration.

Lessons from this intervention

This type of breakdown clearly illustrates the importance of:

  • Check the refrigeration connections regularly.

  • Ensure stable and level support for the outdoor condenser.

  • Perform seasonal maintenance before summer to avoid performance losses.

At AirGreen , we always emphasize prevention. A simple annual inspection can often prevent costly repairs and ensure increased longevity of your Tosot system.

Why choose AirGreen for your Tosot repairs in Montreal

Our certified technicians specialize in the repair and maintenance of Tosot, Gree, Fujitsu, Midea, and Sharp systems throughout Greater Montreal. With our advanced diagnostic tools and field experience, we provide:

  • A quick and precise intervention .

  • Genuine parts recommended by the manufacturer.

  • Guaranteed professional service , from diagnosis to restart.

We serve the entire territory: Montreal, Laval, Longueuil, the North Shore and the South Shore , with teams available 7 days a week for your HVAC emergencies.

AirGreen Expert Advice:
If your wall-mounted air conditioner is no longer cooling, don't wait for the situation to worsen. Low refrigerant pressure puts additional stress on the compressor, which can lead to complete system failure.

Call AirGreen at the first sign of inefficiency— simple preventative maintenance can extend the life of your appliance by years.

AirGreen — Your trusted HVAC partner in Montreal, Laval, Longueuil, North Shore and South Shore.