There is no summer like the summer in the GTA. A hot house can feel like a hot oven, even in the middle of winter, if there is too much humidity, regardless of which part of the province you live in, whether it’s Mississauga, Hamilton, Oakville or Milton. When it is so warm that nothing is cold in your home, and you start using your air conditioner, you become very angry.
If your air conditioner is not cooling as it should, you’re not the only one. This is one of the most frequent HVAC issues that we hear throughout the Greater Toronto area all summer long. The good news? Many of these problems can be easily solved and some of them can even be corrected without a technician’s help.
Let’s take a look at the most common causes that may be causing your air conditioner to blow warm air but not cold and what you can do to fix your air conditioner working before the heat intensifies.
Why Is My AC Running But Not Cooling the House?
Do not panic due to the following: If an AC is on, but not cooling, it does not necessarily mean it’s broken. In many instances, it is an indicator of something basic that is being overlooked, such as a dirty filter, or an incorrect thermostat setting. However, it can also indicate more severe issues that require the help of a professional.
Here are the most common culprits:
- Dirty or Clogged Air Filter
- Incorrect Thermostat Settings
- Low Refrigerant or a Refrigerant Leak
- Frozen Evaporator Coils
- Blocked or Dirty Condenser Unit
- AC Fan Not Working Properly
- Aging or Undersized System
1. Dirty or Clogged Air Filter
This is the number one cause of poor AC performance and the easiest to fix. Your air filter will clog up due to dust, pet dander and other debris more rapidly than you may think, and this will reduce the flow of air. Your system has to work twice as hard to produce the same cooling.
If the filter becomes clogged, the evaporator coil may freeze and turn off the cooling system.
Quick Fix: See if your filter is working right now! Replace if it is gray and matted. The filters in Canadian homes should be replaced every 30-60 days, particularly during periods of heavy use. This is a single step which fixes more AC problems for most homeowners than they would ever expect and it’s very inexpensive.
2. Incorrect Thermostat Settings
Although it seems easy, a thermostat setting problem is responsible for more AC issues than you’d imagine. When the fan is on rather than “Auto” it operates all of the time, pumping cold air through your vents when the cooling cycle is not running. This will make it seem as if your AC is not cooling, but it actually is, it just has a setting flaw.
Quick Fix: Ensure your thermostat is in “Cool” mode, the target temperature is below the temperature in the room and the fan is on “Auto.” Replace batteries if the screen is dim or unresponsive.
3. Low Refrigerant or a Refrigerant Leak
The material used to transfer the heat from the inside to the outside is called refrigerant. When a refrigerant level is low, whether it’s your refrigerator or your AC, it can’t do that heat exchange process with much effort, especially if it’s low on refrigerant, which is almost always caused by a leak.
Some symptoms are hissing or bubbling noises from the unit, ice build-up on the indoor coil or the outdoor unit always running and never cooling the house.
Important: This is not a “do it yourself” repair. The handling of refrigerants is regulated in Canada and refrigerants may only be handled and recharged by people who are certified HVAC technicians. Low refrigerant in the system can lead to destruction of the compressor, a much more costly repair.
4. Frozen Evaporator Coils
When there is limited air flow (usually due to dusty filters or not enough refrigerant) or a low refrigerant, the moisture can accumulate on the evaporator coils and freeze solid. After they have frozen, the coils won’t be able to pull heat from the inside air, and warm air is just pushed through your vents.
Quick Fix: Turn AC to 0 and set the fan to “On” so that the coils can thaw (several hours). When it is thawed, inspect and replace the air filter. When the freezing occurs again and again, it’s a sign that the time has come for a professional inspection.
5. Blocked or Dirty Condenser Unit (Outdoor Unit)
Your condenser (the one outside) is responsible for pushing the heat out of your home. Surrounded by leaves, overgrown grass or a season’s worth of debris it can not do its job properly. There’s nowhere for the trapped heat to escape and your house stays warm.
Quick Fix: Remove at least 60 cm around the outdoor unit. Fins may be gently rinsed with a garden hose, but not washed with a high pressure hose as this can bend the very delicate fins. When the coils are in deep dirt, the best way is to have a professional clean them.
6. AC Fan Not Working Properly
The condenser fan removes heat from the refrigerant which can be cooled again. When the AC fan is not working, heat escapes the system inefficiently, regardless of whether it spins slowly, makes noise or doesn’t move at all. This results in a unit that never turns off and doesn’t cool the room.
Here are some signs of a fan problem: When the AC is making loud noises (grinding, rattling or clicking), or the fan is hot to the touch after prolonged use, there is a problem. Don’t ignore these sounds. One of the first signs may be if the air conditioner is making loud noise, which could be a prelude to a total breakdown.
This can be a window unit, a central system or an air cooler – any unusual noises from the fan always indicate a need for immediate air cooler repair or HVAC inspection before the issue becomes even more serious.
7. Aging or Undersized System
Older air conditioners (over 12-15 years old) may not be able to cool the home as effectively as they did in the past. Parts become worn, performance declines and on a 35°C day in Ontario in the summer a worn or undersized unit will simply not be able to keep up.
For such situations, an AC installation of a newer, more energy-efficient air conditioning system, such as a newer mini split air conditioning or mini ductless air conditioning system, can make a huge difference in comfort and monthly utility costs.
Can a Leaking Air Conditioner Cause Cooling Problems?
Yes. Any leaking air conditioner whether it’s refrigerant or even a condensate water leak can certainly have a negative impact on the system’s performance. Leaks in the refrigerants decrease refrigeration capacity. Water leaks are typically due to a clogged condensate drain and can not always inhibit cooling itself, but can cause safety shut-off switches and can cause mold or water damage if not corrected.
Don’t shrug off puddles around your indoor unit. This should warrant an immediate AC repair call.
Does AC Troubleshooting Fix Everything?
Simple troubleshooting for AC issues, such as filter change, thermostat adjustment and clearing away debris around the outdoor unit, can solve many problems. When your central AC unit is not cooling, or if you haven’t followed the steps above, it’s time to contact a certified HVAC technician, however, if you have an air conditioner but it’s not working, then it’s time to call a certified HVAC technician.
Running a system that does not work correctly can make the problem start even more severe and costly to remedy.
When Should I Call a Professional for AC Repair?
Call a professional if:
- The AC runs constantly but your home never reaches the set temperature
- You hear unusual sounds grinding, hissing, or clicking
- You see ice on the unit or refrigerant lines
- There’s water pooling around the indoor unit
- The circuit breaker keeps tripping when the AC runs
- Your energy bills have spiked with no clear reason
Once you’ve already performed the simple fixes, and still can’t fix your air conditioner, don’t continue operating one that is not working efficiently. Over time this can escalate to the expensive replacement of the compressor. The better option is to find AC repair and service close to you and schedule a same-day inspection.
Certified technicians can fix most HVAC problems in a single service call, frequently the very same day you call, at virtually any location in the greater Toronto area for HVAC repair, AC service near me, or service AC near me all in the GTA.
What If I Have a Plumbing Emergency at the Same Time?
It’s more common than you might think that during the hottest weeks of summer, Ontario homeowners have a number of issues burning in their homes. Leaks from the AC don’t happen at 3 o’clock in the morning; neither do a leaky pipe or a clogged drain. When having to deal with HVAC problems at the same time as plumbing emergencies, you need a reliable plumbing company that’s available and can get there rapidly.
You can never be left in a pickle if you have a reliable plumber’s service at your fingertips when it comes to a leaking pipe beneath the sink, a flooded basement or a blocked below ground drain. Check if the company provides coverage for any time of the day except working hours as they may be available during emergencies to provide 24×7 emergency plumber near me service.
Signs Your Air Conditioner Is Not Cooling Properly
Usually, there are minor indicators that a homeowner will see that the system isn’t working properly before it breaks down entirely. Detecting them early can prevent the cost of repairing the air conditioner in the future.
Common signs include:
- Warm air blowing from vents
- Weak airflow from the AC system
- AC running constantly without cooling
- Higher hydro bills during summer
- Uneven cooling between rooms
- Strange smells or loud noises
- Ice buildup on the outdoor unit
- Water leaking around the system
If you have a central ac problem with cooling and it persists for a couple hours or more, it is best to call an ac repair service for the problem before it escalates.
About BOS Plumbing and Drains
BOS Plumbing and Drains has been providing trusted home services to the Greater Toronto Area for more than 20 years. BOS provides reliable and expert plumbing and drainage services to homeowners and businesses in Mississauga, Oakville, Hamilton, Milton, Niagara, Cambridge and the GTA.
Whether it’s a plumbing emergency, you need a residential plumber or are looking for an emergency plumber in Mississauga or a plumber in Oakville Ontario, BOS Plumbing and Drains offers the professionalism and experience your home deserves and offers same day service. They have a staff of licensed commercial and residential plumbers who can attend your home or business any time day or night to provide all your plumbing needs.
Looking for a 24-hour plumber, a local emergency plumber or a plumber near me in Hamilton or Milton? BOS Plumbing and Drains has all your needs covered.
When Should You Call for Emergency AC Repair?
Some cooling problems shouldn’t wait. You should contact emergency HVAC professionals immediately if:
- The AC completely stops during extreme heat
- Burning smells come from vents
- Electrical issues occur
- Water is leaking heavily indoors
- Loud banging or grinding noises start
- Elderly family members or children are affected by indoor heat
How Can You Prevent Future AC Cooling Problems?
Preventive maintenance can save thousands in future repairs.
Tips to Keep Your AC Cooling Properly
- Change filters regularly
- Schedule yearly maintenance
- Keep outdoor units clean
- Avoid blocking indoor vents
- Seal air leaks around windows
- Upgrade aging thermostats
- Address strange noises early
Small maintenance habits can significantly reduce emergency breakdowns.
Frequently Asked Questions
1. Why is my AC running but not cooling the house?
These are the most frequent causes: dirty air filter, thermostat problems, low refrigerant, frozen evaporator coils and the outdoor condenser being blocked. Before calling for AC repair, check your filter and thermostat – these are two of the most essential things to check first.
2. Can I fix a central AC not cooling on my own?
Tasks such as changing a dirty filter, cleaning outdoor unit debris or resetting the thermostat are safe DIY tasks. But a leaky refrigerant, snowed-on coils, and problems with the compressor call for an HVAC technician.
3. How often should I service my air conditioner in Canada?
It’s recommended to schedule a professional AC service at least once a year ideally in the spring before the summer heat sets in. Most of the common problems associated with AC not cooling properly can be avoided by regular maintenance.
4. What does it mean if my AC is making a loud noise?
If a loud noise, like grinding, rattling or hissing, is coming from the AC, it may be a sign of a failing fan motor, refrigerant leak or loose internal parts. Don’t dismiss these sounds. Switch off the unit and call the HVAC expert right away.
5. Is it worth repairing an old AC or should I replace it?
When your system’s more than 12-15 years old, and you’re having to repair it regularly, it may make more sense to replace it. Modern mini split and central AC units are much more energy efficient and will save you money in the long run as well.