Annual Furnace Maintenance Checklist
Regardless of where you live, when winter is around the corner, you want to ensure your propane or natural gas furnace is ready.
In most parts of Canada and a good portion of the United States, furnaces are still the primary source of home heating.
Most of us don’t turn on our furnaces until at least October, which means they’ve been off for almost six months (if you’re lucky enough to live somewhere temperate).
Before the cold air arrives, it’s vital to perform some regular furnace maintenance tasks.
These tasks make sure that your furnace is not only functioning optimally but actually working.
Here are the top 10 essential DIY furnace maintenance activities that everyone should perform at least once a year.
1. Clean Your Air Ducts, Vents, and Furnace Filters
When it comes to heat transfer having proper airflow is critical.
You should be cleaning your vents and replacing your furnace filter at least twice a year, but it becomes even more critical during the winter when you run your gas furnace more regularly.
Now, if you’re looking for immaculate air, you have an enormous variety of air filters and cleaning systems to choose from.
But that’s a whole other article, and if you want to read more about indoor air quality and your furnace filter, you can find it here: Your Air Filter Guide. What MERV Rating Do I Need For My Home?
Cleaning your ducts and vents is an involved process.
You’ll need your vacuum cleaner and hose (ideally a shop-vac) as well as a brush, microfiber cloths, and a screwdriver to remove the vents.
To get started, you’ll want to cover your registers with paper towels or cleaning cloths.
The dust blows out of your registers and will otherwise end up in your home.
Then, switch off the heat supply but not the power because you will use the fan to blow dust out of the furnace and vents and into your supply register.
Turn off the fan and use your vacuum (or a brush) to remove the debris from your supply registers.
If you don’t have a long hose attachment, get a long broom to reach into the piping system.
Then, you can remove the air registers and remove the dust from these, too.
From here, you can start to get into your main ducts.
Turn off the fan and the total power supply to your system.
You’ll need a heavy-duty vacuum cleaner (a shop vac) to get this done – your home vacuum won’t be powerful enough.
This is perhaps the most complicated and messiest part of the process, so you might find professional help beneficial.
Don’t forget to check the exhaust flue while you’re at it!
Once everything is tidy, you can replace your air filter with a clean one.
You’re now also ready to clean the other components of your heating system.
Related Reading: What You Need to Know About Ductwork Cleaning
2. Check For Leaking Doors and Windows
Not all homes are created equal, and older ones can have a lot of drafty areas.
Look around your home for drafty areas and do your best to seal up the drafts…
Every little bit of heat you let out is like throwing cash in the trash.
If you have broken windows or old doors, now might be the time to fix them.
3. Clean Your Heat Exchanger
The heat exchanger in your furnace is a critical component: it heats the air used to generate the heat for your home.
It also needs cleaning at least once a year to remove dust and debris and ensure it functions properly.
In order to clean it safely, turn your system off and make sure you turn the gas off, too, if applicable.
You may need to remove the flame sensor, flame ignitor or pilot light, and burner assembly to better access the burner tubes.
You’ll want these parts removed to clean them later, anyway.
Then take a brush and remove any dirt or debris from the dirty burners.
If necessary, use a damp cloth to remove any hardened buildup.
Finally, use a narrow vacuum attachment to clean out all the chambers of the block assembly.
You may need to tape a 3/4″ hose to the end of your vacuum to reach the back of the burner tubes.
If your system is older, you might benefit from a professional cleaning.
An experienced HVAC technician will reach all the appropriate parts and be able to check for a cracked heat exchanger.
Damage to this furnace part can cause carbon monoxide leaks, which are very dangerous.
4. Check Up on Your Blower Motor and Fan
Your blower motor circulates the air into the vents, and dust buildup on the blower fan vanes can stop it from functioning correctly.
You should clean out your blower assembly while the system is completely off.
To clean the blower motor and fan, you’ll start by removing the blower door.
🛑 SAFETY FIRST: Before conducting any DIY furnace maintenance, ensure your furnace is off by killing the electrical power and fuel supply.
Turn the gas supply off at the main gas valve.
You may also need to remove the blower switch.
Then, use a screwdriver to remove the fan from the cabinet, but watch both your fingers and the wiring.
You don’t want to compromise the wiring on the cabinet edges.
Grab the vacuum hose to clean the cabinet and the motor, and then use either a toothbrush or a paintbrush on the blower wheel.
Be careful not to get any dust into the blower motor, as it could damage the windings and cause premature failure.
If you’re worried about ruining your motor you should either leave it alone or hire an experienced HVAC technician to perform your annual furnace inspection and maintenance.
✅ PRO TIP: You may think the furnace maintenance cost is high when you hire a contractor, but the cost of improperly doing this yourself could be significantly more.
After cleaning the motor, you may find you need to lubricate it.
To see if your HVAC system requires this step, check your owner’s manual.
Then, clean the caps on the blower bearings before removing the bearings to lubricate them.
A clean furnace blower assembly ensures that you have sufficient airflow during the heating season, which will significantly reduce your energy costs.
5. Change the Batteries in the Thermostat and Check Its Settings
Imagine calling in a heating contractor and paying them $150 to turn your thermostat to heating.
It happens more than you think, so check your t-stat and ensure it’s set right.
Every HVAC maintenance plan includes checking the t-stat settings and confirming it works properly and changing the batteries on the thermostat and, if applicable, carbon monoxide detectors.
Now that you have new batteries installed let’s see if your thermostat is even functioning.
Once you’ve completed your furnace cleaning, changed your furnace filter, tightened any electrical connections, and put the furnace doors back on, you can now switch the power back on (and restore the gas if necessary).
Now, head over to your thermostat and turn up the temperature.
A functioning thermostat will turn the heat on in about 1-5 minutes.
If there’s a digital display, you may see the words “HEAT ON” flashing.
The t-stat does this while it goes through its timer.
Once the timer is complete, the “HEAT ON” stops flashing.
At that point, if you don’t hear the furnace start-up, then you could have a problem with the thermostat itself.
Start by removing the cover and checking your connections.
The wire connections should all be in place.
✅ PRO TIP: check YouTube or Google if you don’t know how to do this. (You can also ask an HVAC company to do this if you’re not comfortable).
If the wires look fine, double-check that you switched on the power source after cleaning.
If it still doesn’t work, then you need an HVAC professional.
The culprit could be one of many parts, including your blower, heat pump, or furnace fan. it could also be a faulty thermostat.
A professional can test each part and find the culprit.
6. Flame Sensor, Pilot Light, and Flame Ignitor
Every furnace tune-up includes checking the furnace’s flame sensor, pilot light, and flame ignitor.
To do this, you’ll want to remove them and blow off any dust or debris build-up, making sure not to touch the flame ignitor with your bare fingers.
For the flame sensor, you can also clean it with an Emery cloth.
If you want to learn more about flame sensors, you should check out our article, which focuses completely on them.
Related Reading: How to Clean a Furnace Flame Sensor in 5 Easy Steps!, and How to Diagnose and Repair a Bad Furnace Ignitor
When you first start your furnace back up, you’ll want to make sure it either has a strong pilot light flame or that your furnace ignitor sparks clearly or glows bright orange.
If the flame lights and stays lit, then your flame sensor is good.
7. Why Does My Furnace Smell?
When you first turn your heating system on, you may smell a slight burning smell…
It’s probably just the dust burning off on your burners, but if the smell persists, make sure to take the necessary safety precautions.
Your furnace room should not have paints or chemicals stored in it.
Even though you might not smell them, their fumes can damage the heat exchanger in your furnace.
This can lead to not only expensive repairs but also carbon monoxide poisoning.
Keep your furnace room clean and uncluttered.
Smells coming from your furnace can be similar to those that can occur with your Air Conditioning.
Check out this article for more information on the most common smells that can come from your HVAC systems.
That may give you an indication of what can be wrong if it doesn’t smell right.
Related Reading: Everything You Need To Know About Your Furnace Room
8. Pre-Season Inspections
Even the most competent DIY-ers benefit from a professional annual tune-up and deep cleaning. Why?
Because almost all HVAC manufacturers require one as part of their warranty.
Skipping your regular maintenance can seriously hurt you if your furnace breaks down during the winter.
If you really want to make sure that your furnace will run safely and reliably throughout the winter, then you should consider purchasing maintenance agreements for your home’s HVAC system.
Professional HVAC companies perform a thorough maintenance checklist on each piece of equipment, ensuring they operate for years to come and meet the manufacturers’ warranty guidelines.
So be prepared and organize an inspection before it’s too cold.
✅ PRO TIP: if you hire them under an annual furnace maintenance agreement, you’ll get a better deal on the pre-season inspections, and most companies offer premium service at a discounted rate if there happens to be an unscheduled breakdown.
✅ Quick Tip: Keep your HVAC Technician Informed
Make sure to keep notes on any issues you might have with your furnace, heating system, or air conditioning.
Keep all of your invoices from previous HVAC technician visits, and store all of this information near your furnace…
It could save you hundreds of dollars on future furnace repairs by helping to inform the current service technician of past problems.
9. How Old Is My Furnace?
If you look at your heating system, and it looks like it might fetch a pretty penny on Antique Roadshow, it might be time to get quotes on a new furnace.
Make sure to get at least three quotes; they will all be similar, but it will help you feel comfortable that you’re getting a fair deal.
You can also save money if you ask about purchasing an annual inspection agreement at this time.
10. Seal Your Supply and Return Ducts
Duct leakage means the air from your furnace isn’t going where it should.
You can easily fix this by getting special metal tape and using it to seal as many joints on the ductwork as possible.
The better the ductwork is sealed, the more energy efficient it will be.
Related Reading: How Does Residential Ductwork Work? A Homeowners Guide!
Final Furnace Maintenance Tips
Are you ready for the cold months ahead?
There are things every homeowner should do before the first cold snap arrives.
At a minimum, you should test your thermostat, switch the furnace on at least once, and replace your filter for the season.
If your furnace won’t start up you may have bigger problems.
However, these maintenance tasks are the bare minimum.
Furnace maintenance, like cleaning your blower and ducts and furnace burners, prevents furnace disasters from compromising your safety and your bank balance when winter hits for good.
Plus, it protects your warranty if your HVAC system is relatively new.
Don’t wait to use these tips.
It won’t be long until the weather changes, and that’s when all of the procrastinators get together and decide to call the local HVAC service company simultaneously.
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All the best and have a warm and comfortable winter!
Want to learn more about your home’s heating system? Feel free to check out our other furnace articles.