01 Aug. 19

Common air conditioner faults that you need to know

When it comes to your air conditioner, maintenance is everything! Air conditioning is important in Toronto, especially in the summer months. Sometimes, the weather can get pretty unbearable hot if your air conditioner is not operational. You know how hot summer nights can be in the cities of Canada especially if you happen to live in Toronto, where the temperature can get as high as 95°F. We recommend you make it a point of duty to keep your air conditioner in good shape.

Air conditioner repair can sometimes be very expensive. Therefore, as you open the drapes, clean the house and prepare for the summer months, check if your air conditioning system is functional especially after those long months of hibernation. 

One of the most common air conditioner faults is improper operation. This might come up due to improper installation or poor maintenance. When your air conditioner is in operation, make sure that all the doors and windows in your house are properly shut. The performance and efficiency of your air conditioner are paramount as it determines how comfortable you will be in your home. This article contains information on common faults that are associated with an air conditioner.

Related article: How often should I service my air conditioner?


Why Maintenance is Key

Usually, air conditioner manufacturers produce well-engineered and typically high-quality systems with impeccable performance. The efficiency of your air conditioning system is totally dependent on the components and units of the system. 

For example, the outdoor unit comprises the condenser and compressor while the indoor unit comprises the condenser, fan, and the filter. Both units need to work together in sync to cool your home effectively. For that reason, they need to be serviced and maintained regularly. 


Common air conditioner faults 

Before the summer seasons begin in Toronto and you start craving cool air in your home, it is always a good idea to check the functionality of your air conditioning system. This will go a long way to make you aware of the variety of faults that can develop so as to know how to tackle them when the faults arise. Here are a few air conditioner faults you may experience if you do not step up your maintenance game.

Thermostat malfunction

Most homeowners in Toronto pay little attention to air conditioner maintenance. The repercussions are not that far behind as their ACs begin to develop different faults and malfunctions that lead to the high cost of repairs. Most air conditioning systems in the Toronto market are well designed to function efficiently. Nevertheless, faults still crop up every once in a while. One of the common components that develop faults easily is the thermostat.

Problems manifest quickly in the thermostat and regular inspection is required to avoid any problems or malfunction of this major component. Your thermostat is important to the proper functioning of your air conditioner. It controls and regulates the temperature in your home. The thermostat measures the temperature in your home and regulates your AC unit to release cool air until your desired temperature is reached.

If not serviced regularly, it can develop an array of issues, some of which include:

  • Low responsiveness to your input temperature
  • Running beyond its stop time
  • Refusal to stop running after your home has reached your set temperature.
  • Extremely high or low temperatures in your home
  • Overheating outdoor unit
  • Fluctuations in temperature
  • Coolant leaks

All of these symptoms point directly to a malfunctioning thermostat. It can be totally avoided by contacting an air conditioner professional anywhere in Toronto to check on your thermostat regularly. An expert can come to your house to have it serviced once every month. This will save you headaches and discomfort in your home.

Related article: Does my HVAC need a smart thermostat?

Leaking ducts

Water leaks from ACs are a major concern for homeowners in Toronto. There are other issues that can arise from this such as mould growth and property damage. Your AC system works by absorbing all the hot air and moisture in your home. The absorbed air is passed through the condenser to reduce the temperature, converted to liquid and then passed out through the drain line.

For a central AC system that uses ductwork, the units extend to the walls and ceiling of the house.  Through the ducts, cool air is distributed in your home. However, it has been discovered that 30% of cool air is lost while it is being transferred through ducts. This is as a result of leakage. There are several factors responsible for leakages in your ducts or vents. Some of them are:

  • Escaped air from the vent
  • Clogged drain line
  • Dirty air filters
  • Uninsulated ducts
  • Broken air pump
  • Damaged drain pan
  • Leaking coolant

When coolant begins to leak from your AC ducts, the temperature in the house begins to fluctuate, the whole air conditioning system is affected and if not properly fixed, the whole system can be damaged. This fault is due to poor maintenance. To avoid this, call an HVAC contractor to have your ducts checked monthly.

Related article: Why your air conditioner is leaking water?

Compressor issues

All types of AC have four major mechanical components: a condenser, expansion valve, evaporator, and a compressor. An AC system works by converting refrigerants from gas to liquid and vice-versa. The compressor’s major function is to absorb cool air/ refrigerants from the indoor environment, compressing it in order to increase the temperature and then releasing the refrigerant in gaseous form outdoors.

The temperature and pressure of the refrigerant are increased so it can be released as a high-pressure gas. Without the compressor, air can be exchanged, meaning no cool air in circulation. Here a few causes of compressor failure:

  • Blocked drain line
  • Dirty coils
  • Low refrigerant charge
  • Wrong size of the drain line
  • Electrical fluctuations
  • Inadequate lubricants
  • Debris in the system

 On a sunny afternoon in summer when the temperature reaches as high as 80 °F, failure to maintain your AC compressor may spell discomfort. You can totally avoid spending a ridiculously huge amount to repair your compressor by developing an excellent maintenance routine.

Blocked filters

Air conditioning is a vital part of many homes in Toronto. The air filter is important but most of the time overlooked the component of an air conditioning system. Many homeowners in Toronto are guilty of this. Although it may look like a square of fibres or pleated material, filters in air conditioners play a major role in the overall comfort of your home. The performance and efficiency of your HVAC system are totally dependent on the functionality of the filters.

Filters are cardboard-like in shape and are usually made from fibres, cloth or pleated paper material. Their main function is to circulate air delivered through the indoor unit. Filters hold different contaminants that can affect the quality of air in your home. Such contaminants include hair, animal fur, dust, pollen, moulds, wood particles, microorganisms and bacteria. 

Filtration occurs when compressed and released air is brought back to be distributed indoors. The air passes through the filter and then removes all particles and contaminants from the air.  Once the filter is not cleaned regularly, these particles begin to pile up on the filters and eventually block the air space.

The good thing is air filter maintenance is not tedious and doesn’t require the assistance of an HVAC professional. A clogged air filter will reduce the flow of air and make the AC system work twice as hard, which may result in system overheating. There are many reasons why you should avoid a clogged filter some of which are:

  • Better air quality: Filters maintain the quality of air in your home. They protect your home from dust, microorganisms, bacteria, pollen, etc. During allergy months. It is best to replace filters regularly. If you have pets in your home, your filters should also be changed regularly.
  • Improves energy efficiency: When your filters are free of clogs, they have fewer emissions and help you save energy.
  • Lower cost of running your HVAC system: When your HVAC operates at maximum efficiency, you use less power. The cost of running your AC is lower when compared to other utility bills.
  • Ensure the longevity of your system: Clean filters guarantee the longevity of your AC system. The Life of your HVAC is undoubtedly extended since there are zero contaminants in the atmosphere.
  • Better health for you and your family: When your air filter is clean, you have no worries during the flu season. You will be sure of getting good quality air in your home.

Related article: When to clean your HVAC air ducts?


Leaky refrigerant

If your AC is not maintained constantly, it will begin to leak at some point. This is not necessarily because your system is not of good quality. It’s just because your system is experiencing some faults due to poor maintenance practices. You need to service it every once in a while to avoid this common air conditioner fault. 

Refrigerant leaks are part of the number one problems many homeowners face in Toronto. One thing to take note of is that refrigerant is not like the oils in your car that need to be replaced. An HVAC system running efficiently uses the same amount of refrigerant over the course of its operations. 

Let’s explore the symptoms/signs of a refrigerant leak

  • Loss of cooling capacity: It is the job of the refrigerant to trap heat from your home and dump it outside. If your refrigerant starts leaking, there is a drop in the level of refrigerant which automatically leads to hot temperatures. Your home will no longer be properly cooled appropriately. 
  • Vents blowing room temperature air instead of cool air: If the air coming from your vents is not cold and is measured at room temperature or even warm, then your refrigerant may be leaking.
  • The indoor unit starts producing hissing sounds: Leakages occur when the coils that surround the refrigerants begin to have holes or cracks. Hissing sounds are mostly related to refrigerant leakage.
  • Coils begin to freeze: When the level of refrigerant in the coils is very low, the coils will be unable to absorb heat and will begin to freeze. This can lead to a system breakdown and high repair costs.
  • The electric bill drastically increases: If your air conditioner is not working efficiently, chances are high that you will resort to using it more often than you should. This increases your electricity utility and may cause a rise in your utility bill.

Related article: What is Air Conditioner Refrigerant and How Does it Work?

Clogged drain line

The drain line plays a crucial role in the overall performance of your HVAC system. It is simply a pipe that drains water into a pan outside your house. It is a component of the outdoor unit and helps the system to effectively drain itself of excess water and refrigerants. Since it is located outdoor, most Toronto homeowners assume it’s of little or no significance. 

If it is left unattended to, dirt, mould and debris begin to accumulate inside the pipes and this is where your air conditioner faults begin. The blockages due to these clogs can cause corrosion inside the pipes and this worsens the problem. Here are the symptoms of a clogged drain line:

  • Wet walls: If the wall beside your AC begins to get damp, then it is likely that there is a problem with your drain line.
  • Mould in drip pan: Drip pans should never be wet. They should always be dry because any water deposited in it ideally should be emptied outside. Mould grows in dark and damp places. So if you notice mould growth on your drain line, it is a sign that water is not being drained effectively.
  • Water leakage: If you notice any leakage from your AC unit, it could be any of two things. It is an indication that either your drain line is clogged or it’s totally damaged.
  • Musty smell in your house: Musty smells are usually due to mould growth somewhere in your house. So check to ensure that there is no other leakage in your house. If there isn’t take a screwdriver and check your AC.

A clogged drain line can affect the efficiency and effectiveness of the entire system. Proper maintenance should be carried out constantly to avoid this air conditioner fault.

Dirty condenser coil

The condenser coil is a part of the outdoor unit. This means that it is constantly exposed to dirt and unwanted particles. If not checked regularly, the deposition of these particles can get out of hand and a number of issues will ensue. Some of the possible issues caused by dirty coils include:

  • Loud noise coming from the outdoor unit
  • Warm air
  • Low refrigerant
  • Leaks
  • Cooling capacity dropping by 30%
  • A rise in energy consumption
  • System malfunction
  • System break down

Your condenser coil does not have the capacity to withstand much dirt. All it takes is a 1/23 increase in dirt levels to shut down the entire system down. The compressor coil is always outdoors. The best way to protect the life of your system is to employ the services of an HVAC professional. An expert should carry out regular check-ups and services on your system.

Issues with the capacitor.

Most home homeowners in Toronto are unaware of this component. It is small but it remains a vital part of the HVAC system. The capacitor can be compared to the starter of your car.

The starter sets the motor in motion by starting the process of combustion. The capacitor is present to keep the HVAC system running. During regular AC servicing, it is the responsibility of the HVAC technician to make sure the capacitor of your air conditioning system is in good shape. Here are some causes of Capacitor malfunction:

  • The age of your AC: The life expectancy of your capacitor is directly proportional to the age of your system.
  • Power fluctuation: Issues with your capacitor may arise if there is a constant variation in power voltage. Power companies sometimes lower and increase your electric voltage especially during summertime. This can damage your capacitor.
  • Summer heat: Theme rate of capacitor damage and malfunction gets on the high especially during summer in Toronto.

Capacitors are connected to high voltage so maintenance should not be ignored. If not properly checked, overheating may occur and the entire system may be at risk. 

Problem with the blower motor

The blower motor is that part of the AC unit that keeps air moving throughout the system. It enables the effective circulation of air. If the blower motor breaks down, the entire HVAC system shuts down. It can’t be seen by merely using a screwdriver to open up your AC.

It works anonymously and can only be noticed when it develops a fault. The major causes of a blower motor issue are dirt accumulation and poor maintenance. Common symptoms of a faulty blower motor are: 

  • The fan blows only at a certain speed: Different types of ACs all around Toronto have motor blowers that are designed to function at different set speeds. This feature helps you to regulate the temperature in your home. If you notice that the fan is blowing just at one particular speed, then there is an issue with the blower motor of your AC.
  • Lower cooling capacity: If you turn your AC on and you notice it takes forever for your home to get evenly cold, then there is a problem with the blower motor. This is usually characterized by weaker air coming from the vents or ducts.
  • The fan blows no air at all: If no airflow is produced at all, you need to replace your fan blower. It means your blower is not functional anymore and needs to be replaced or repaired.

Contact any HVAC the technician in Toronto and get your AC checked. Neglecting the blower motor can result in an unexpected system shut down.

Related article: Central Air Conditioner fan not working: what to do



Air conditioning system maintenance is not the same as taking a walk in the park with a bowl of ice cream. It requires you to be intentional, deliberate and proactive. It is a routine you must stick to ensure your system safety and performance. 

Practicing religious air conditioning system maintenance will avoid repeated repair visits and expand the lifespan of your air conditioning system. Our HVAC experts can help you make sure that your air conditioning is always maintained. Call us today!