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Réparation d’une thermopompe murale Fujitsu à Saint-Lambert
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Repair of a Fujitsu wall-mounted heat pump in Saint-Lambert

When a Fujitsu heat pump stops heating in the middle of spring: AirGreen expertise at work

At AirGreen , we frequently work in Saint-Lambert , on the South Shore of Montreal , to diagnose and repair Fujitsu wall-mounted heat pumps that have lost performance after several seasons of intensive use. This case perfectly illustrates a typical situation: a unit that seemed to still be working, but was no longer blowing hot air, leaving the house uncomfortable on cool May mornings.

Initial diagnosis: a faulty defrost system and a tired engine

The customer contacted us after noticing that their Fujitsu wall-mounted heat pump was no longer producing heat, even though the indicator lights appeared to indicate normal operation. Upon arrival, our certified technician noted:

  • The indoor fan was running intermittently.

  • Defrost mode was triggering too often, even without ice buildup.

  • The outgoing airflow was warm and uneven.

  • The outdoor unit showed a light layer of frost , a sign of a faulty defrost cycle.

At this point, it was clear that the problem was an aging electronic control board that was unable to properly manage the heating and defrosting sequence.

Additionally, the indoor fan motor exhibited low starting torque—a warning sign of wear.

Repair steps: complete system restoration

Our technicians followed a rigorous procedure to ensure a long-lasting repair that meets the manufacturer's standards:

  1. Complete dismantling of the facade and the interior turbine.

  2. Cleaning the evaporator coil with steam and biodegradable degreaser to restore heat transfer.

  3. Testing the control board with a digital multimeter: inconsistent reading of the defrost relay output voltage.

  4. Replacement of the electronic card with an original Fujitsu part.

  5. Lubrication and refurbishment of the interior blower motor , then checking the fan rotation.

  6. Complete system reset and performance test.

  7. Blowing temperature measurement : 46°C in heating mode, fully in line with specifications.

Result: restored performance and comfort regained

After the repair, the customer immediately noticed a noticeable change:

  • The indoor temperature stabilized in less than an hour.

  • The noise level of the unit has decreased thanks to the engine refurbishment.

  • The defrost sequence has been standardized, eliminating unnecessary cycles that increased energy consumption.

Thanks to this intervention, the Fujitsu heat pump has regained its full efficiency, providing both optimal heating and cooling for the coming season.

The importance of regular preventative maintenance

This case highlights a key principle in the HVAC field: the majority of breakdowns can be prevented by a comprehensive annual maintenance. At AirGreen, our maintenance includes:

  • Checking refrigerant gas and operating pressures.

  • Cleaning the indoor and outdoor coils .

  • Inspection of electrical connections and electronic boards.

  • Testing the temperature sensors and the condensate drain .

  • Calibration of operating modes (heating, air conditioning, defrosting).

A well-maintained heat pump consumes up to 20% less energy and extends its lifespan by several years.

Why choose AirGreen for your Fujitsu heat pump in Saint-Lambert?

As a Montreal-based HVAC company, AirGreen stands out for:

  • Technicians specialized by brand , including Fujitsu, Gree, Midea, Sharp and Trane.

  • Genuine parts guaranteed and installed according to manufacturer protocols.

  • Extensive coverage in Montreal, Laval, Longueuil, the North Shore and the South Shore.

  • A transparent approach : precise diagnosis, clear explanations and documented interventions.

Every service call is treated as a long-term partnership. Our goal: to repair rather than replace , whenever economically viable.

When should you contact us?

Here are some signs that warrant a prompt service call:

  • Your heat pump no longer blows hot or cold depending on the season.

  • You hear an unusual noise when starting.

  • The compressor frequently stops for no apparent reason.

  • Flashing lights are displayed on the indoor unit.

  • Your electricity bill increases without changing usage.

Prompt diagnosis often prevents more extensive repairs and extends the life of the system.

AirGreen: the HVAC benchmark on the South Shore and throughout Greater Montreal

Whether you are in Saint-Lambert , Brossard , Longueuil or elsewhere on the South Shore , our technicians travel quickly to diagnose and repair all types of residential HVAC systems .
Our reputation is built on three pillars: speed, precision, and durability . Every intervention, like the one carried out here in Saint-Lambert, demonstrates our commitment to maintaining optimal comfort in every home.

In summary:
The repair of this Fujitsu wall-mounted heat pump in Saint-Lambert restored full performance after replacing the circuit board and servicing the motor. This was an AirGreen service—meticulous, durable, and focused on customer satisfaction.