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Réparation d’une thermopompe Slimair UC à Sainte-Julie
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Repair of a Slimair UC heat pump in Sainte-Julie

A service call under a blazing sun

On a hot summer day in Sainte-Julie , our AirGreen team was called to diagnose a problem with a Slimair UC heat pump installed on the flat roof of a commercial building. This type of installation, common for small businesses or multi-unit residential buildings, often exposes the outdoor units to extreme weather conditions, accelerating the wear and tear of certain essential components.

Initial observation: loss of efficiency and unusual noise

The customer reported a loss of air conditioning performance accompanied by a metallic noise at startup. Upon accessing the roof, our technicians noticed that the condenser, although visually clean, appeared to be vibrating irregularly. The fan was running, but the expelled air was lukewarm, a clear sign of an incomplete refrigeration cycle .

In-depth diagnosis: R-410A refrigerant leak and compressor vibration

After conducting a series of tests—pressure measurement, pipe temperature, and acoustic inspection—we identified a minor leak on the Schrader valve of the service circuit. This type of leak is common in installations exposed to significant temperature variations, such as those on flat roofs. Furthermore, the vibration originated from a slightly unbalanced compressor , likely due to a cracked shock absorber mount.

Repair steps

  1. Safe recovery of the remaining refrigerant to avoid any release into the atmosphere, in accordance with environmental standards.

  2. Replacement of the faulty Schrader valve with a reinforced model compatible with R-410A.

  3. Repair of the shock absorber mount under the compressor and realignment of the unit.

  4. Complete vacuuming to eliminate all traces of moisture and air.

  5. Precise recharge with R-410A refrigerant according to manufacturer's specifications Slimair UC-314.

  6. Final performance test , including overheating and subcooling measurements to ensure optimal operation.

Results: Performance and comfort restored

After restarting, the heat pump regained its full cooling capacity. The metallic noise disappeared , and the system pressure stabilized. The customer immediately noticed a significant improvement in the indoor temperature. By checking the power consumption, we confirmed that the unit was operating at its rated output, ensuring optimal energy efficiency .

AirGreen's preventative advice

For systems installed on flat roofs, such as this Slimair UC-314 , we recommend:

  • Biannual maintenance including condenser cleaning and pressure checks.

  • An inspection of the fixings and anti-vibration supports at each visit.

  • Monitoring the refrigerant level to prevent chronic leaks that reduce the compressor's lifespan.

  • Adding a protective shelter or partial sunscreen to limit direct sun exposure.

Our expertise at your service

At AirGreen , we combine our field experience with rigorous technical training to diagnose and repair all brands of HVAC systems —from residential wall-mounted heat pumps to central and commercial systems. We serve all of Montreal, Laval, Longueuil, the North Shore, and the South Shore , with certified technicians and guaranteed original parts.

Thanks to this successful intervention in Sainte-Julie, the Slimair UC-314 heat pump is ready to face a new season, ensuring constant comfort and lasting efficiency for its owner.