Repair of a Haxxair wall-mounted heat pump in Boisbriand (North Shore): restoring an Inverter unit that was no longer cooling

In Boisbriand, on the North Shore, a client contacted us because their Haxxair wall-mounted heat pump ( Inverter outdoor unit) seemed to be working… but wasn't actually cooling. The fan would run intermittently, then the unit would pause; inside, the feeling of coolness never arrived like it used to. In this type of situation, our goal at AirGreen is simple: diagnose quickly, repair properly, and stabilize the system to prevent a recurrence .

What we observed upon arrival

The Haxxair outdoor unit was installed on a wooden deck , on anti-vibration mounts , with adequate clearance around the grille. A white sheath protecting the connections (refrigerant lines and wiring) was also visible, with a service loop near the base—a useful detail for servicing the pipes without putting stress on them.

Visually, there was no indication of impact or major damage (no obvious signs of crushing on the battery, no deformed casing). So, we immediately switched to a "field" approach: symptoms → measures → root cause .

Symptoms reported by the customer

• Very little cooling, especially in the afternoon

• Irregular cycles (the machine “starts” then stops)

• Uneven comfort: some rooms remain damp and warm.

• No clear error code reported to the customer

This type of chart can point to several causes: airflow , sensor , control board , abnormal pressure , or even insufficient refrigerant charge (micro-leak) — but we never “guess”: we measure.

Our diagnostic process (step by step)

1) Validation of conditions and functional testing

We first checked the settings (mode, setpoint, speed), then started an air conditioning cycle to observe:

• the start-up of the inverter compressor,

• the stability of the regime,

• the thermal response (supply/return temperatures).

Result: correct start-up , but unstable performance , with an impression of a system that is "protecting itself" or lacks margin.

2) Control of airflow and heat exchange

Insufficient airflow can mimic a refrigerant failure. Therefore, we have:

• inspected the general condition (filters, cleanliness of the evaporator on the inside),

• checked the exchange on the outdoor unit (battery, ventilation, clearance).

Airflow was not the primary cause: the installation and environment were reasonable.

3) Refrigeration measurements and interpretation

Next, let's look at the data: pressure, superheating/subcooling (depending on configuration), and behavior under load.
The values ​​pointed to a performance that did not reach the expected level , typical of a refrigerant charge that was too low or a slight restriction.

In residential settings, the most frequent cause in this scenario is a progressive micro-leak , often on a fitting, a braze, or a point subject to vibrations/thermal variations.

4) Targeted leak detection and localization

We conducted a structured search:

• inspection of accessible fittings,

• verification of junction points and sensitive areas,

• confirmation by appropriate method on site.

We have identified a weak point at a junction (classic area: fitting/connection), discreet enough not to “empty” the system at once, but real enough to degrade performance over time .

The repair carried out by AirGreen

Once the cause was confirmed, a clean, durable repair, in accordance with best practices, was applied:

1. Securing and preparing working conditions

   • System shutdown and securing

   • preparation of the intervention area to prevent any contamination.

2. Vanishing point correction

   • resumption of the connection/point concerned (depending on the system configuration),

   • restored to the expected sealing standard for stable operation.

3. Circuit stabilization

   • Vacuuming if required by the procedure,

   • stability check to validate that the leak is actually eliminated.

4. Recommissioning and adjustment

   • recharge/adjustment according to system specifications.

   • Complete restart and observation of the Inverter's behavior under load.

Results: restored comfort and stabilized performance

After the repair, the Haxxair wall-mounted heat pump returned to normal operation:

• more stable cycles,

• resumption of effective cooling

• a feeling of comfort quickly, even when the outside temperature rises.

• quieter operation (often an indirect effect when the system is no longer “in trouble”).

The customer particularly noticed the following difference: the air becomes fresher faster and the humidity decreases , which immediately improves comfort at home.

Why this type of failure occurs (and how to avoid it)

On a wall-mounted inverter heat pump, a slight lack of refrigerant can:

• reduce yield,

• to trigger protective measures,

• increase long-term wear (because the machine compensates by working “badly”).

To prevent:

• periodic maintenance (inspection + cleaning),

• a connection check during a service,

• and above all: intervene at the first signs (decreased performance, irregular cycles).

AirGreen in Boisbriand and throughout the North Shore

At AirGreen, our approach is the same on every call: rigorous diagnosis , lasting repair, and clear explanation to the customer. Whether it's for a Haxxair wall-mounted heat pump or any other residential system, we aim for a concrete result: stable comfort and a reliable machine .