Sudden power outage in downtown condo
In the vibrant heart of Ville-Marie , a client recently contacted us about a heating and cooling problem in his condo. His wall-mounted PTAC (Packaged Terminal Air Conditioner) unit—a self-contained system often used in apartment buildings and hotels—was no longer blowing either cold or hot air. At AirGreen , we're familiar with this type of unit: compact, efficient, but requiring rigorous maintenance to avoid unexpected shutdowns.
The context: an aging system at the edge of the window
The device, installed directly under a large window overlooking the street, showed obvious signs of wear:
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Yellowing of plastic caused by time;
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Air vents clogged with dust ;
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Intermittent noises each time the compressor is tried to start.
This type of installation, common in buildings in Ville-Marie and Plateau-Mont-Royal , operates without ducts and combines both electric heating and refrigerant air conditioning . Our mission: to bring this equipment back to life without disturbing the resident's comfort.
Step 1: Complete on-site diagnosis
Upon our arrival, we performed a complete visual and electrical inspection of the system. Here are the initial findings:
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No response from compressor on startup;
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Fan works , but no cold ;
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Slight hum from the relay , indicating correct voltage but compressor start failure .
Using our multimeter, we checked the continuity of the starting capacitor , a component often responsible for this type of failure.
Result: defective capacitor - it no longer provided the nominal capacity required to start the compressor.
Step 2: Replacing the capacitor and cleaning the internals
We replaced the 35/5 µF start capacitor with a compatible model of the same voltage, then undertook a complete cleaning of the system:
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Dusting the evaporator coil;
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Cleaning the condenser coil at the rear of the unit;
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Disinfection of the condensate tray and the tangential fan;
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Checking airflow and drainage .
Once these operations were completed, we reconnected the electronic module and restarted the system.
Step 3: Performance testing and calibration
After a few seconds, the compressor started up normally. The following readings confirmed proper operation:
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Outlet air temperature: 12°C ;
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Circuit pressure: stable and compliant ;
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Absence of abnormal vibrations ;
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Balanced power consumption .
We've also recalibrated the built-in thermostat to prevent overly frequent start-up cycles—a common problem in older models.
AirGreen Expertise: Repair rather than replace
Many building owners in Montreal choose to replace their PTAC units at the first sign of failure. However, in most cases, a targeted repair like this can extend the system's lifespan by several years at a fraction of the cost.
Our AirGreen certified technicians service new and older Amana, Friedrich, LG, Trane, and Zephyr models weekly. With our compatible parts inventory and diagnostic tools, we can often get a unit back up and running the same day .
Prevention: How to avoid PTAC breakdowns
PTAC units are robust, but they often suffer from poor maintenance . Here are our recommendations to avoid emergency calls:
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Clean the filter every 6 weeks;
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Check the drainage tray to avoid water overflow;
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Move curtains and furniture away from the front grille;
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Schedule annual preventative maintenance with an AirGreen technician.
An annual inspection can prevent up to 80% of breakdowns related to dust or internal corrosion, especially in downtown Montreal buildings exposed to pollution and humidity.
Result: a satisfied customer and restored comfort
After our intervention, the client found a stable temperature in his condo, both for heating and air conditioning. We left maintenance recommendations and noted the model for possible future replacement with an energy-efficient PTAC using the more environmentally friendly R-32 refrigerant.
This repair is a perfect example of the AirGreen approach: transparent, efficient, and sustainable . Each intervention aims to provide our customers in Greater Montreal with optimal comfort, without unnecessary expense.
Why choose AirGreen for your PTAC system repairs?
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Recognized expertise in autonomous and commercial systems;
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EPA and TSSA certified technicians ;
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Rapid intervention in Montreal, Laval, Longueuil, North Shore and South Shore;
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Written warranty on every repair.
AirGreen: Your trusted HVAC expert for PTAC system repair, maintenance, and replacement in Montreal.