common furnace problems

15 Common Furnace Problems That Will Stop It From Working Rightly

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common furnace problems

Being cold when you wake up in the middle of the night, especially in Canada, is the worst thing. The covers need to be pulled up if that’s all you need to do. In the same way, another issue arises if your furnace performs poorly or not at all. You can diagnose the issue with your furnace and sometimes repair it yourself if you have some basic DIY skills. Learn more about the most common furnace problems in Canada by reading on.

How to fix some of the most typical furnace issues

Some common furnace problems in Canada happen more often than others. What seems like a big problem with your furnace might be easy to fix. In the next section, I’ll talk about some of the most common furnace problems in Canada:

1. Your furnace stopped working

The cycle on your common furnace problems just began, but it abruptly stopped before the room warmed to the desired temperature. Similar to other furnace issues, a tripped circuit breaker, an issue with the pilot light or ignition, an obstruction in the airflow, or a tripped safety switch might all cause a furnace to cease operating. The best course of action if your furnace shut off for no apparent reason is to contact a qualified expert to examine it and determine what’s wrong.

2. Unclean Filters

It is crucial to replace your furnace filters regularly. The passage of air is halted by blocked filters. This forces your furnace to work harder, which may lead to an overheated heat exchanger that shuts down your appliance.

One scenario is that you’ll have a furnace that doesn’t perform effectively and costs more to provide less heat. The worst-case scenario is that you’ll shorten the lifespan of your furnace and have a chilly home. Your furnace may be gasping for air if it isn’t producing enough heat or constantly turning on and off. Replace those filters.

3. Unlocked Access Panel

You should be aware that to access the components within your furnace, you must open a panel. The furnace won’t even turn on if the panel isn’t completely closed. Another measure of safety to protect people from harm!

4. Your heater sometimes turns on and off

Your common furnace problems will cycle on and off as it warms your house to maintain the thermostat setting. A furnace may kick on, heat the space or house to the required temperature, and then shut off many times an hour depending on the thermostat setting and the weather outside.

5. Your furnace sometimes turns on and off

When a furnace begins short cycling or often goes on and off without ever reaching the set limit temperature, something is often wrong. The furnace barely runs for a few minutes during a brief cycle before shutting off once again. Lack of airflow in the furnace typically results in it being excessively hot, which results in a short cycle. Furnaces include safety switches that, if activated, will shut down the system if it becomes too hot.

The engine may overheat and the safety switch may trip if the air filter is unclean because it may obstruct airflow. You may wish to examine and replace the air filter as a first step if your furnace often switches on and off or only runs for a short period at a time and never reaches the temperature you desire. You’ll need to get a specialist to check things over if replacing the air filter doesn’t resolve the issue.

6. A defective speed limiter switch

Your limit control switch could be at fault if your blower fan continues to operate even when your thermostat is set to AUTO rather than ON. This switch, which is located just underneath the box that directs heat from the furnace to the ducts, shuts off the system when the air becomes too hot. Your limit switch has to be changed or replaced, which is a task for a professional if the device never shuts off.

7. A damaged blower capacitor

The blower motor’s actual power comes from the capacitor. It functions like a battery, discharging amps of energy to run the machinery. The circuit board becomes the only source of power for the motor if the capacitor fails. As a result, the power increases swiftly. It can result in a short circuit or the circuit breaker tripping.

A furnace that begins to operate but then stops in the middle is often the result of a damaged blower capacitor. A heating, ventilation, and air conditioning (HVAC) expert can assess the damage and determine if a replacement is necessary.

8. A defective thermostat

Your furnace receives instructions from the thermostat about when to turn it on and how warm your home should be. Your furnace’s performance may be significantly impacted if the thermostat stops functioning properly. You could have issues like intermittent heating, brief cycling, or difficulty turning on or off. Either your home is too hot or too chilly. Your thermostat can be defective and in need of replacement, but it’s also conceivable that the batteries are just dead. To check if it helps, try installing a fresh set of batteries.

9. Worn and torn components

Over time, your furnace will begin to malfunction. Years of repeated heating and cooling may cause components to become dull, twisted, sluggish, or jumbled. The whole system may malfunction if just one of these components stopped functioning. It’s difficult to pinpoint precisely which component is faulty without training. You must contact a qualified technician. By doing this, a technician will visit your house equipped with the most up-to-date diagnostic equipment to inspect your furnace from top to bottom. In only one visit, many furnace issues may be resolved.

10. Unclean Burners

You won’t have any heat if your burners get blocked since they won’t be able to release enough natural gas to burn. When the burner has blue flames, it is operating effectively. Any other shade, such as yellow or orange, indicates the presence of debris. The attempt to ignite a filthy burner may also result in a loud boom-rumble. Cleaning the burners could be simple if you’ve done it previously.

11. Furnace water leaking 

Water may collect around the base of certain furnace models as a result of condensation leaks. The cool exhaust function of your high-efficiency furnace is likely to present if your annual fuel utilization efficiency (AFUE) is above 90%. Metal pipes are often replaced by PVC pipes in high-efficiency furnaces. Additionally, they feature pipes for condensation, which direct water formed while fuel burns and cools to a drain. Water may gather around the base of the furnace if the condensation line becomes blocked or develops another kind of leak. The best course of action in such a situation is to contact a professional to investigate.

12. A flickering, weak, or oddly colored pilot light

Without a functioning pilot light, your furnace cannot function properly. It might indicate that there is too much carbon monoxide in your gas furnace if it flickers or goes yellow. Call a furnace professional in your region if you wish to replace your pilot light.

13. A heat exchanger malfunctioning

Unfortunately, this condition is quite pricey. The air in your furnace is kept from being overheated by the flame thanks to your heat exchanger. If you overheat your home or don’t replace your air filters often enough, your heat exchanger may get damaged. You should contact a specialist to diagnose the issue if your heat stops functioning. This often indicates that it is time to replace the heat exchanger.

14. A grinding or scraping noise is coming from the furnace

If your blower is making a grinding or scraping noise, this indicates that the ball bearings are worn out, and you should immediately switch the appliance off. You’ll want the assistance of a certified HVAC specialist for this adjustment.

15. The Starting Mechanism’s Repair

Every furnace has a method for accelerating the heating cycle. The kind of mechanism is dependent upon the furnace. There is often a pilot light in an ancient furnace. Most modern furnaces now employ electrical ignitions rather than pilot lights.

No matter what kind of furnace you have, the ignition or pilot light might break, necessitating repair or replacement. Your furnace may fail to ignite or maintain a pilot light, preventing it from heating your house. You may be able to see the pilot light within the furnace. However, if your furnace doesn’t come on when it should, you should contact an HVAC specialist.


I know that this article told you how to fix some of the most common furnace problems, but sometimes you need to call an expert. Have you tried any of the repairs you can do yourself?

Having your system checked out every so often, or at least as often as the manufacturer suggests, can keep a small problem from turning into a big one. Remember that fixing things yourself can be satisfying and save you money, but you should make sure you have the skills before you try to fix your furnace.

If the tips don’t help you find or fix problems, or if they are too hard for you, you may need to hire a professional to fix your furnace. It’s so important to clean and tune up your HVAC system every season, especially in Canada. Most people forget about it until it stops working.


In Canada, how long do furnaces last?

 Depending on when it was installed, a furnace can work reliably for 15 to 20 years, and probably longer if it is taken care of. As it gets close to 15 years, look for signs of wear and tear and check your bills for any strange charges.

What brand of furnace is the most reliable in Canada?

Buy from companies whose furnaces are known to be reliable, efficient, and of good quality. Trane, Carrier, Lennox, Goodman, Bryant, York, Amana, and Keeprite are the most popular brands in Canada. The design and quality of these products from these brands are different.

Should I replace a furnace that is 17 years old?

The National Association of Home Builders says that, on average, most furnaces last between 15 and 20 years. This depends on the brand and how much regular maintenance was done during those years, but it’s a good way to figure out when you might want to get a new one.

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