A service call in a hotel-style condo
At AirGreen , we often receive calls from high-end residential buildings and condominiums in Montreal , where PTAC (Packaged Terminal Air Conditioner) air conditioning and heating systems are installed under the windows—like in hotels. This was the case for a client located in Westmount , who contacted us after noticing that their unit was no longer blowing hot air, despite having a thermostat set to maximum.
On-site diagnosis: internal electrical fault in the module
Upon arrival, our technician found that the wall-mounted unit—a PTAC of approximately 12,000 BTUs installed under the living room window—was no longer responding to commands. The fan remained inactive, and no compressor sound was audible. After a thorough inspection, the diagnostic revealed:
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Unstable power supply due to a partially disconnected outlet.
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Poorly insulated wires inside the lower cabinet of the unit.
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A thermal control board damaged by a power surge.
These systems, often old, are connected directly to a 240 V circuit and require special attention when handling.
Repair carried out by our AirGreen team
After turning off the general power supply, our CMMT certified technician proceeded to:
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Replacing the control card with an equivalent model compatible with the same generation PTACs.
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Reworking the internal wiring , replacing the oxidized wires and adding new insulating sheathing to prevent any risk of short circuit.
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Checking the fan motor , followed by a complete cleaning of the coils to restore optimal air circulation.
Once everything was reconnected, the system resumed normal operation, providing constant and stable hot air.
Result: restored comfort and stabilized performance
In less than two hours, the Westmount client was able to regain ideal thermal comfort. The repaired PTAC unit now offered:
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A stable room temperature , without fluctuations or unwanted noise;
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Improved energy efficiency , thanks to cleaning the coils;
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Guaranteed electrical safety , with connections redone according to RBQ and Canadian Electrical Code standards.
AirGreen Recommendations for PTAC Owners
Our experts remind us that annual preventative maintenance is essential to extend the lifespan of these devices. Common problems with PTAC systems include:
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Dust accumulation in the coils;
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Condensates not properly evacuated, causing infiltration;
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Control boards damaged by overvoltage;
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Faulty thermistors (temperature sensors).
We also recommend installing surge protection and checking the dedicated circuit breaker.
Our expertise serving Montreal and its surrounding areas
At AirGreen , we work on all types of residential HVAC systems, whether it's PTACs, wall-mounted heat pumps, central air conditioners or electric furnaces . We cover all of Greater Montreal , including Westmount, Laval, Longueuil, the North Shore and the South Shore .
Our priority: guaranteeing the comfort, performance and safety of each customer, with fast, precise and sustainable service.