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Réparation d’une thermopompe murale Sharp sur le Plateau-Mont-Royal (Montréal)
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Repair of a Sharp wall-mounted heat pump in Plateau-Mont-Royal (Montreal)

In an apartment in the Plateau-Mont-Royal neighbourhood , our AirGreen team intervened to recommission a Sharp wall-mounted heat pump (mini-split type). In the photo, you can clearly see an indoor wall unit installed very high on the wall , near the ceiling, above a living area (sofa) — a common configuration in Montreal condos and apartments, where the aim is to maximize comfort without sacrificing square footage.

In this context, good performance depends as much on the machine as on simple but crucial installation details: ceiling clearance , blowing direction, condensate drainage , and quality of the refrigeration connection (often concealed in the wall for a clean result, as here).

The system in question: Sharp wall-mounted heat pump (recent residential range)

  • Type : wall-mounted heat pump (mini-split indoor unit)

  • Brand : Sharp

  • Model (consistent with the Sharp range) : Sharp ZU1 (R-32 wall-mounted, standard residential size)

Even though the exact model isn't visible in this photo, the shape and size correspond very well to a recent Sharp wall-mounted unit. The most important thing on-site is to accurately diagnose the cause of the malfunction and verify that the installation allows the unit to operate without any issues.

Symptoms reported by the customer

The client contacted us about three typical problems, often related to each other on a mural:

  1. Unstable cooling (temperature that “no longer follows” despite the setpoint)

  2. Reduced airflow during operation, especially after a few minutes

  3. Occasional presence of water (or moisture) near the indoor unit

In an apartment, these symptoms quickly become uncomfortable: disturbed sleep, heavy air, a feeling of humidity, and the impression that the heat pump is "forcing" itself without result.

Our AirGreen diagnostic (complete method, no assumptions)

With a Sharp wall-mounted heat pump, we avoid quick diagnoses like "low refrigerant" (often false and unnecessarily costly). We follow a structured approach:

  • Visual inspection of the indoor unit (cover, fins, condensate tray)

  • Checking the condition of the filters and the fouling of the coil

  • Condensate drain control (slope, obstruction, flow)

  • Performance measurements: return/supply air temperature, fan stability

  • Verification of operating parameters and tests in air conditioning and heating modes

  • If required: refrigerant side pressure/temperature check (without overloading the system)

What we observed

In this case, the main cause was twofold (and very common in wall units in urban areas):

  1. Partially blocked drain : water drains poorly, which can cause intermittent overflows and disrupt performance.

  2. Clogged coil and turbine : air circulates less well, the machine exchanges less efficiently, and the feeling of “weakness” appears quickly.

When a wall-mounted drain is installed high (as is normal here), an imperfect drain or progressive fouling can go unnoticed… until the day comfort suddenly drops.

The repair steps performed

Here is what we accomplished on site, in a clean and safe manner (protection of furniture, controlled work area, damage-free cleaning):

1) Complete cleaning of the indoor unit

  • Cleaning of accessible filters and air ducts

  • Cleaning the coil (evaporator) with a suitable HVAC product

  • Cleaning the turbine (blower wheel) to restore airflow

  • Light sanitation to limit odors and biofilm (depending on the condition)

2) Refurbishment of the condensate drainage system

  • Drain unblocking (checking for obstruction, rinsing/flushing)

  • Flow control under real-world conditions (extended test)

  • Check the alignment and level to prevent water from "flowing back" into the tray

3) Performance checks and final tests

  • Air conditioning test: stability of the supply temperature, flow rate, noise

  • Heating test: temperature rise, modulation, no alarms

  • Monitoring behavior after a continuous period (important: some problems appear after 10–20 minutes)

Results: Comfort restored and function stabilized

After the procedure:

  • Airflow restored (more consistent airflow, better distribution throughout the room)

  • Faster and more stable cooling at the same setpoint

  • Disappearance of signs of water accumulation related to drainage

  • Quieter system (turbine fouling often increases noise)

The customer noticed one very concrete point in particular: the room becomes comfortable again without having to lower the setting excessively, which is exactly what you want with a well-maintained wall-mounted heat pump.

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

In Montreal condos/apartments, several factors accelerate soiling and drainage problems:

  • Fine dust, textiles, continuous air circulation

  • prolonged use in air conditioning (significant condensate production)

  • long or concealed drains (more difficult to check without a method)

  • Maintenance too infrequent (even if “it still works”)

Our AirGreen recommendation: regular preventative maintenance (especially before the hot season) avoids the majority of emergency calls and prolongs the life of your Sharp .

AirGreen: Sharp heat pump repair and maintenance in Greater Montreal

We serve all of Montreal and the surrounding areas, with a simple approach: thorough diagnosis, targeted repair, and clear explanations. A well-maintained Sharp wall-mounted heat pump can provide excellent comfort, summer and winter—provided that air circulation and drainage are in perfect working order.