Fedders wall-mounted air conditioner repair in La Prairie

Urgent call for a wall-mounted air conditioner that's out of breath

At AirGreen , we were recently contacted by a resident of La Prairie , on the South Shore of Montreal , about a problem with a Fedders wall-mounted air conditioner that was no longer producing cold air, despite the “cool” mode being activated and a compressor that seemed to be working intermittently. This situation is typical of a unit that is more than ten years old and whose regular maintenance has been neglected, especially after several winters without a complete cleaning of the condensation circuit.

The unit in question was installed in the living room, directly above a television and near a large patio door, a common arrangement in condominiums and apartments. This configuration often exposes the unit to faster clogging caused by dust and direct sunlight.

Detailed diagnosis of the Fedders wall-mounted air conditioner

Upon our arrival, our certified technician performed a complete system diagnosis:

• Electrical check : the supply voltage was stable, with no apparent disconnection.

• Control panel inspection : buttons responded, but a delay in response indicated a possible electronic board problem .

• Temperature sensor test : readings were erroneous, suggesting a faulty thermistor .

• Evaporator coil inspection : significant accumulation of dust and lint, reducing airflow and heat exchange.

After cleaning the evaporator and filter, we noticed a slight improvement in airflow, but the compressor refused to maintain a stable cooling cycle.

Repair: Refurbishing the control circuit

The Fedders model had a classic flaw: the main control board (PCB) was corroded due to ambient humidity. So we have:

1. Removed the front panel and isolated the electronic board .

2. Cleaned the contacts and checked for weak solder joints.

3. Replaced the faulty thermistor (temperature sensor).

4. Reset the control circuit to recalibrate the compressor start.

After reassembly, the wall-mounted air conditioner restarted normally. The compressor started smoothly, and the expelled air quickly reached 12°C , confirming the return of effective cooling.

Prevention and recommendations

We advised the client to:

• Have the filter cleaned every 4 to 6 weeks during the summer season.

• Schedule a full annual maintenance before the start of summer.

• Avoid partially covering air outlets with curtains or furniture.

We also suggested considering, in the medium term, replacing the wall-mounted air conditioner with a modern wall-mounted heat pump . Newer models—including Midea, Gree, or Fujitsu —offer better energy efficiency (SEER greater than 20) and quiet operation, ideal for residential environments.

Final result

Thanks to a quick and targeted repair , we extended the life of the Fedders wall-mounted air conditioner by approximately 2 to 3 years, while restoring the resident's comfort. She was able to enjoy a pleasant indoor temperature, even during La Prairie's hot days.

At AirGreen , every HVAC repair intervention aims to offer a durable, economical solution that complies with the standards of the Régie du bâtiment du Québec (RBQ) . Our team operates throughout the South Shore , as well as in Montreal, Laval and the North Shore , to ensure the performance and reliability of your air conditioning and heating systems.