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Réparation d’un système PTAC Friedrich à Ville-Marie
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Repair of a Friedrich PTAC system in Ville-Marie

A technical intervention in an old building in the city center

At AirGreen , we were recently called for a repair service on a Friedrich PTAC system installed in a residential building in the Ville-Marie district of Montreal. The customer contacted us after noticing that the unit was no longer blowing cold air, despite the compressor apparently working. This type of system, often used in downtown rental or commercial buildings, requires special attention due to its wall-mounted installation and the complexity of its maintenance.

Diagnosis on a PTAC Friedrich

Upon arriving on site, our technician immediately noticed that the PTAC (Packaged Terminal Air Conditioner) system was installed in a solid wooden structure attached to an exterior brick wall. The Friedrich unit was well ventilated, but there was an abnormal noise and a slight odor of overheating. After a few checks, we identified the following points:

  • The air filter was completely clogged.

  • The interior fan impeller was clogged, slowing down airflow.

  • The evaporator temperature sensor was sending incorrect signals to the electronic board, causing the cooling cycle to stop prematurely.

Steps of repair

1. Complete cleaning of the air circuit

We started by disassembling the front panel of the unit to remove the air filter and impeller . After a thorough steam cleaning and gentle rinsing, we restored optimal airflow through the evaporator.

2. Electrical check

Our clamp-on current tests revealed an imbalance in the current drawn by the fan motor , confirming the need for recalibration. We inspected the control board , replaced the faulty probe , and then reprogrammed the startup sequence.

3. Repressurizing the refrigerant circuit

A suction pressure measurement showed a slight loss of R-410A refrigerant. A microscopic leak was detected at the condensing coil connection. We performed copper-phosphorus brazing , then performed a full evacuation before recharging the system to Friedrich specifications.

Result: performance and comfort restored

After restarting, the Friedrich PTAC quickly returned to its original performance, achieving a stable supply air temperature of 10°C. The customer, who operates several apartments in the building, appreciated our speed and the care taken to ensure the safety of the wall installation.

We also recommended biannual maintenance , especially for this type of device exposed to the dust and pollution of downtown Montreal.

This type of PTAC system repair perfectly illustrates the importance of preventive maintenance : a simple clogged filter can, over time, lead to a major compressor failure.

AirGreen Tips for Building Owners in Montreal

To extend the life of your PTAC devices:

  1. Clean the air filter every two months.

  2. Check condensate drains to prevent water from overflowing inside.

  3. Visually inspect the rear panel for signs of oil or frost.

  4. Call a certified technician for any abnormal noise or loss of performance.

Thanks to our experience in central districts such as Ville-Marie, Le Plateau and Le Sud-Ouest , we are well aware of the constraints of installation in old buildings and masonry structures.

AirGreen: Your HVAC Repair Expert in Montreal

At AirGreen, we don't just repair: we optimize every HVAC system to operate reliably, safely, and energy-efficiently. Whether it's a Friedrich PTAC , a Fujitsu wall-mounted heat pump , or a Lennox central air conditioner , our team operates with rigor and transparency.

We operate throughout Greater Montreal: Montreal, Laval, Longueuil, North Shore and South Shore .