How Do I Maintain a Furnace Myself?

Furnace maintenance can be quite pricey. It comes as no surprise that you might be wondering ‘how do I maintain my furnace myself?’.

Homeowners can follow a furnace maintenance checklist, in case they don’t want to invite a professional over. The checklist includes inspecting all the parts of the system, checking the cleanliness of the unit, ensuring that there are no blockages, and performing a furnace cleaning.

How often should your furnace be serviced? Where inside the system can you find all these parts that need extra attention? And, finally, are there any specific tasks that should be taken care of only by an experienced professional?

Don’t worry, you are about to become a furnace maintenance expert.

How Often Do Furnaces Need to Be Serviced?

HVAC experts recommend getting your furnace checked every year.

Annual maintenance is not a necessary thing and your furnace can end up working perfectly fine, even if you skip a year.

Related: American Standard Furnace – Troubleshooting Guide

However, regular maintenance is definitely beneficial for the whole system and will result in the following advantages:

Preventative maintenance helps you avoid costly expenses. During the check-up, a professional (or even you yourself) can find a few minor issues that will be fixed straight away.

However, if neglected, these small problems might lead to huge issues in the future and such repairs would cost you a small fortune.

Regular maintenance increases the efficiency of the system and reduces your energy bills. Even simply changing the filter boosts the efficiency of the system and immediately improves the air quality. Check-ups help increase the lifespan of your furnace.

Have a Question? Ask HVAC Technician

Click here to use the chatbox to speak with one of our technicians.
No in-home service calls. No appointments.

Furnace Maintenance Schedule

In general, it is recommended to give your furnace an annual ‘glow up’ before the beginning of the heating season. Usually, in the fall.

If you want to go the extra mile, you can go through the furnace maintenance checklist once again in spring (just to make sure that nothing happened to the system during the heating season). 

Fact: be prepared to pay anywhere between $100 and $300 for furnace inspection, tune-up, and cleaning, if you choose to call a professional.

What You Should Do Before Furnace Maintenance

The most important thing that you should do before performing any manipulations is switching the power and gas off.

You would have to remove the fuse, trip the circuit breaker, or simply open the box located next to your furnace and shut it off.

If you know that you are going to be exposed to dust or debris, wear a respirator and goggles. Put gloves on whenever handling anything that can potentially cut you.

Prepare the required tools. In the majority of cases, you are going to need a screwdriver, a vacuum cleaner, a new filter, a toothbrush or small-sized brush, oil, and a sealant of your choice.  

How to Service Your Furnace – Furnace Maintenance Checklist

Ideally, you would want to invite a professional to come over and check the performance of your furnace.

An expert will follow the necessary safety rules, knows exactly what areas might need some extra attention, and, finally, has all the professional equipment needed.

With that being said, it is not impossible for a regular homeowner to perform furnace maintenance. Simply follow this checklist.

Related: HVAC System Service – How It’s Done and How Much Does It Cost?

Check the venting system for blockages and proper slope

  1. Turn on the system and check all of the vents in the house. If the airflow in one vent is non-existent or weak, then your system might have a blockage.
  2. Fully remove the filter and check if the problem is solved.
  3. Use a screwdriver to remove the vent cover and inspect the area right behind the grill. Sometimes, you will find pieces of paper or even fabric there.
  4. Use a flashlight to inspect the part of the ductwork past the grill. All debris has to be removed.
  5. Visually inspect the whole ductwork and make sure that there are no holes and that all the pipes are nicely fitted.
  6. Check if the butterfly valves are open (the handles have to be parallel to the ductwork).

At this point, a professional is going to perform a combustion test, in case you have a gas furnace.

A special tool will help make sure that there are no cracks in the system that can lead to carbon monoxide leaks. 

Inspect the heat exchanger

A lot of furnaces nowadays do not provide easy access to their heat exchangers. 

But if your model does offer access, use a flashlight and a mirror to check this part of the unit for any cracks. Pay extra attention to the curves and look for burn marks, stains, corrosion, and rust.

Inspect the belt

You will typically find the blower fan motor near the bottom of the furnace. There, you’ll see the blower-fan belt.

Visually inspect it for wear and tear. Ideally, you would want to have one or two extra belts lying around just in case you need to replace the old one.

If the belt looks good, check the tension – it shouldn’t have more than a half of an inch give either way. To tighten the belt, use the adjusting bolt.

Check the pulleys – they should be in a straight line (the belt shouldn’t be twisting). To make an adjustment, loosen the mounting bolts.

Test the safety switches for proper operation

Gas furnaces have a pressure switch which is, basically, a safety device. The thing prevents the furnace from running, in case the correct air pressure is not present.

You’ll find the device close to the draft inducer motor.

You are going to need a multimeter to check the switch for resistance. If you don’t feel comfortable working with wires, this step should be completed by a professional. 

Check the main blower’s cleanliness, capacitor readings, and amp draws

For this manipulation, you are going to need a non-contact voltage tester (to ensure that the power has been shut off) and a voltage meter (to ensure that the power is able to get to the main blower).

Inspect and clean the evaporator coil and drain pan

Before reaching your rooms, the air travels through the evaporator coil. Naturally, condensate forms on this part and then drips into the pan.

Make sure that the drain pan is not clogged and that it is properly connected to the pipes.

Inspect these parts of the system for rust and corrosion and make sure to use a non-toxic disinfectant when cleaning (this will help prevent microbial growth). 

Perform a temperature rise and static pressure test to measure adequate airflow

It might be better to leave this step to the professionals, as it involves special equipment and requires drilling test ports.

To perform a simplified version of a temperature rise test, you can turn up the temperature about 10 degrees warmer and wait for 15 minutes

After that, put your hand on the ductwork right above the furnace. If you are able to leave your palm on the ductwork without it being too unbearable, then everything is working well.

Check the installation of your filter and its cleanliness

In the majority of cases, the filter access door is located in the return air duct. Sometimes, you’ll find the filter inside the actual unit, next to the blower motor.

Tip: some systems have more than one filter, so make sure to check all of them.

How to Clean Your Furnace – Step-by-Step Instructions

After you have shut down the system, clean the combustion chamber (this step is for the furnaces that use fuel).

Scrape out build-up with a wire brush and remove any debris with a vacuum. Replace the old filter or clean it.

Related: Why Does My Furnace Filter Get Dirty So Quickly

If you decide to clean the filter (it has to be reusable), then simply rinse away the dust with water and let it dry. Don’t forget to mark the direction of airflow before removing the filter.

  • Vacuum out all the ducts – the chances are high that you would have to deal with a lot of dust, hair, and food scraps.
  • Clean the blower and heat exchanger.

Use a stiff brush and soapy water to rinse off the blower blades. Simply vacuum the space around the heat exchanger and use a brush to loosen up any build-up.

  • Don’t forget to re-assemble the unit correctly. You can leave small marks on the components with indications like ‘up’ and ‘down’, for example, to make things a bit easier.
Full furnace Maintenance Guide

To Sum Up

In theory, you can take care of your furnace yourself.

You can check the main components to ensure that everything is okay and you can clean the system to increase its efficiency.

However, homeowners have to be extremely careful when working with wires, high voltage, and gas.

Moreover, some important tests, like the combustion and the static pressure tests and the testing of the safety switches should be performed only by HVAC technicians.

The professionals not only have the right equipment, but they are also able to interpret all the readings correctly

Of course, everything is better than no maintenance at all. But always remember to consult a technician, if in any doubt.