Fujitsu wall-mounted air conditioner repair in Pointe-Claire

A service call during a heatwave on the West Island

It was on a particularly hot day that we were contacted by a customer from Pointe-Claire , on the West Shore of Montreal , about a breakdown of his Fujitsu wall-mounted air conditioner . The unit, installed for several years in a recent condo, was no longer producing cold air despite the “OPERATION” indicator being continuously lit. This type of symptom is typical of a communication problem or an interrupted refrigeration cycle , often linked to delayed maintenance or an electronic failure.

Our client, concerned about the rapid rise in indoor temperature, called on AirGreen for a rapid diagnosis and lasting repair.

Initial diagnosis: advanced fouling and a faulty control board

Upon our arrival, our technicians carried out a thorough inspection of the Fujitsu ASU12RLS3 series indoor unit, a model known for its reliability but sensitive to fine dust and voltage fluctuations. The findings were clear:

• The blower flaps were clogged, significantly reducing airflow.

• The evaporator coil had a thick layer of dust and mold.

• The “OPERATION” light remained steady, while the electronic board refused to enter cooling mode.

• Outside, the compressor would not start , although it was receiving the correct power.

Electrical readings helped identify the source of the problem:
a faulty indoor control board , unable to send the start signal to the outdoor unit. A classic on some generations of Fujitsu when the capacitors on the board lose their capacity over time.

Repair: refurbishment of the electronic card and complete cleaning

At AirGreen, we always prioritize targeted repairs and long-term prevention . After validating the quote, our team undertook a two-part intervention:

1. Replacement of the original Fujitsu internal electronic card , reprogrammed to match the customer's configuration.

2. Complete cleaning of the indoor unit , including:

   • Complete disassembly of the front cover and shutters.

   • Antibacterial cleaning of the coil and turbine fan.

   • Application of a biodegradable disinfectant treatment.

3. Checking the refrigeration circuit using an electronic pressure gauge: pressures compliant, no signs of leakage.

4. Communication test between units (stable 12V DC signal).

5. Restart and calibrate the system.

As soon as the intervention was completed, the wall-mounted air conditioner was blowing air at 8°C , ensuring even cooling in the main room of the condo.

Technical features of the Fujitsu model

The Fujitsu ASU12RLS3 is a 12,000 BTU wall-mounted air conditioner known for its energy efficiency and quietness. However, like many compact models, it requires regular maintenance to prevent:

• Ice formation on the evaporator.

• Random error codes caused by dirty sensors.

• Board failures due to the accumulation of fine dust and moisture in the electronics box.

Our technicians recommend to all Fujitsu system owners:

• A complete internal cleaning every 2 years , including the turbine and coils.

• Annual preventive maintenance in spring to maintain optimal energy efficiency.

• Leave the visible filters clean , but above all do not neglect the internal part of the coil - often a source of excess energy consumption.

AirGreen: HVAC expertise serving Montreal comfort

At AirGreen , we operate every day throughout Montreal, Laval, Longueuil, the North Shore and the South Shore to diagnose, repair and maintain Fujitsu, Gree, Sharp, Midea, Hitachi, Goodman and several other well-known brands wall-mounted air conditioners .
Our approach is based on:

• Accurate diagnostics , based on real electrical and thermal measurements.

• Genuine manufacturer parts for every replacement.

• A transparent and fast service , always with a clear explanation to the customer.

We know every device tells a different story—one of comfort restored, breakdown avoided, and extended performance.

Result: immediate comfort and restored efficiency

A few minutes after the repair, the owner confirmed that the interior temperature had returned to a comfortable level. The unit, quieter than before, displayed stable performance, with a smooth operating cycle and reduced power consumption.

Thanks to this intervention, the Fujitsu wall-mounted air conditioner has regained its original efficiency, ready to face the heat of the Montreal summer.