As summer slowly approaches Toronto, many condo residents begin switching on their air conditioning for the first time in months - only to find that it’s not working as expected. Whether your condo uses a fan coil unit or a heat pump system, there are several reasons your air conditioning may not be performing properly.
Understanding the type of system in your suite, and whether the issue is isolated to your unit or building-wide, can help you get the right kind of help faster.
Most older Toronto condo buildings (1980s-early 2010s) use fan coil systems, often with a 2-pipe configuration, meaning the building toggles between heating and cooling seasonally. These units rely on a central boiler and chiller system to deliver hot or cold water to individual suites.
Newer buildings and retrofits are more likely to use heat pump systems, which are self-contained and transfer heat in or out of your suite using refrigerant rather than water. Unlike fan coils, heat pumps can typically provide both heating and cooling year-round, depending on the building setup.
Fan coil systems are a long-standing standard in Toronto high-rises, but they’re not without their aging pains, especially as many original systems approach or exceed their 20-year lifespan.
Over time, fan coil units accumulate dust, pet hair, and debris in both the coils and the air filters. If these are not cleaned or replaced regularly, airflow through the unit is significantly reduced. This can cause your system to blow lukewarm air or take much longer to cool your condo. Dirty coils also prevent efficient heat exchange, which forces the blower to work harder, raising your energy bills and potentially wearing down the motor prematurely.
One of the most common (and costly) issues with older fan coil units is water leakage. This usually happens when the condensate drain pan, located underneath the coil to collect moisture, begins to rust or crack. Once that happens, water can leak into the surrounding drywall or flooring, sometimes even dripping into the unit below. These leaks can cause mold growth and structural damage if left untreated. In many cases, replacing the drain pan requires cutting into the unit’s cabinet and installing new insulation, making it a job best left to professionals.
If your fan coil unit has started making grinding, buzzing, or rattling noises, chances are the fan motor is nearing the end of its life. Motors in older units often suffer from worn-out bearings or capacitors, especially if they’ve been running continuously for years with little maintenance. In some cases, noise may come from a misaligned fan blade scraping the housing. Left unchecked, these noises can escalate to full motor failure, leading to complete loss of cooling in the unit.
In buildings with a 2-pipe configuration, your unit relies on a changeover valve to switch between heating and cooling during seasonal transitions. If this valve becomes stuck or fails entirely, your unit may continue to blow hot air even after the building has switched to cooling mode, or vice versa. Inconsistent temperature control and no response to thermostat changes are common symptoms. These valves often degrade due to mineral buildup from the building’s water supply or corrosion from long-term exposure.
Heat pump systems offer the convenience of year-round climate control, but like any HVAC system, they come with their own set of issues - especially in the unique context of high-rise living.
Unlike fan coil systems, heat pumps use refrigerant to transfer heat. Over time, tiny leaks can develop in the refrigerant lines, usually at joints or vibration-prone areas. Low refrigerant levels can cause your system to blow warm air in cooling mode or take much longer to cool down your space. More critically, running a heat pump with low refrigerant can overwork and eventually damage the compressor, which is one of the most expensive components to replace. Early detection through pressure tests can help prevent major damage.
If you notice ice buildup on your indoor unit or a sudden drop in airflow, your heat pump’s evaporator coil may be frozen. This typically happens when airflow is restricted, often due to dirty filters, a blocked return vent, or a malfunctioning fan. A frozen coil not only stops the cooling process but can also strain internal components as the system tries to push through the blockage. In some cases, poor refrigerant flow or a faulty thermostat may also be to blame. Turning off the system and calling a technician is often the best course of action to avoid further damage.
Heat pumps rely on a component called a reversing valve to switch between heating and cooling modes. If this valve fails or gets stuck, the system may remain in the wrong mode or blow room-temperature air regardless of the thermostat setting. This issue is most commonly observed during seasonal transitions and can be frustrating, especially when outdoor temperatures fluctuate rapidly in spring or fall. Reversing valve failures are typically electrical or mechanical in nature and require a skilled HVAC technician to diagnose and replace.
Many Toronto condo owners are now installing smart thermostats to better control their HVAC systems. However, not all thermostats are compatible with building-integrated heat pump systems. Incompatible models may misread system behavior or fail to communicate properly with the reversing valve or fan control relay. This can result in erratic performance, constant cycling, or no heating/cooling at all. In some cases, switching back to a standard thermostat or using a manufacturer-approved smart model is the simplest fix.
There are many problems that can be resolved directly by the condo resident hiring a certified HVAC professional:
That said, annual maintenance, while available privately, tends to be much more cost-effective when done as part of a property-managed building-wide service. Many condos coordinate an HVAC tune-up campaign once a year and offer residents the chance to opt in. This allows the service provider to perform maintenance on multiple units in a single visit, which significantly lowers the cost per suite. If your building offers this, it’s usually the best time to schedule inspections and cleanings.
Certain issues originate beyond the walls of your suite and require coordination with the property manager or condo board:
When in doubt, especially if multiple residents are experiencing the same issue, your first step should be to contact building management. They can either confirm the scope of the problem or help coordinate access for qualified technicians.
Whether your condo uses a fan coil unit or a heat pump system, understanding the root cause of an AC issue can help you avoid unnecessary delays and get the right support. In many cases, a trusted HVAC technician can fix the problem quickly and directly. In others, particularly those involving shared infrastructure or building-wide controls, involving your property manager is essential.
Not sure what type of system your suite uses or where to start? Contact us and we’ll help you figure out what’s wrong and how to fix it, so you can stay cool and comfortable all summer long.
We are a leading HVAC company for condos, low rise & high rise apartments in Toronto & GTA. Simply Contact us today to book your next service!
