Furnace Servicing: How Often Should I Clean My Furnace?

Your furnace is one of the biggest and most important appliances in your home. But you might not give it much thought until it starts malfunctioning in the dead of winter. To ensure its continuous operation, you must call a local furnace repair person to schedule furnace servicing at least once a year.

Why You Need Furnace Servicing

Like changing the oil in your car, this annual servicing is a necessary part of HVAC care. You'll extend the life of the system and help head off major breakdowns. Failure to perform needed maintenance is one of the most common causes of HVAC issues. And not maintaining your furnace—whether it's gas or electric—can cause it to run less efficiently, making it work even harder, therefore increasing your monthly energy bills.

How Often Should a Furnace Be Serviced?

An annual furnace servicing is recommended, as it will prolong the system's life span, save energy, and decrease health risks. Some home HVAC warranties will even become void if damage is done due to lack of maintenance.

Manufacturers recommend each side of the system get inspected and serviced once per year, in spring for air conditioning and fall for heating and furnaces.

How often to service a furnace in the future will depend on how well these inspections go. If the HVAC pro keeps finding problems each visit, then it might be time to consider replacing your appliance.

What Happens If I Don’t Service My Furnace?

Some experts say up to 75% of no-heat calls in the winter are related to a lack of maintenance. Left unserviced, a furnace can stop working suddenly, leaving your family in the cold.

It can also be a health hazard. Technicians say a furnace checkup can reveal carbon monoxide leaks, which are hard to detect because gas is colorless and odorless. Carbon monoxide can lead to headaches, dizziness, nausea, and even death. The Centers for Disease Control and Prevention reports that an estimated 420 people die each year and 100,000 people are taken to emergency rooms due to carbon monoxide exposure. In particularly unsafe situations, your furnace could be red-tagged, meaning it can't be activated until repaired.

Also, if you have a newer furnace that is still under warranty, know that skipping out on that annual service call could void any claim you submit when it’s not working properly. While a warranty does state an appliance manufacturer’s promise to repair or replace malfunctioning products, the company is likely to deny any claim that can be traced back to a homeowner who has neglected regular maintenance of the appliance. If you’re unsure whether your furnace is up to par, have a professional inspect it.

“We recently worked on a house that had a relatively new HVAC system, but it was leaking carbon monoxide,” says Robert Tschudi, Expert Review Board member and North Carolina-based home builder and remodeler. “Not only did we end up replacing the entire unit, we also replaced the carbon monoxide sensors inside the house.”

Furnace Servicing Costs 

If you have a company only come out to do an inspection, you may have to pay a small trip charge or service fee. Ask if that amount will come off your bill if you have work done. On average, furnace cleaning costs $60 to $85.

Technicians will make sure everything is safe, as efficient as possible, and running at peak performance.

“Before the HVAC pro comes to your house, turn on the fan, heat, or air conditioning and check every register to see if air is coming out,” says Tschudi. “That way, the pro can diagnose any problems on the same service call, such as disconnected or damaged ducts.”

What Annual Furnace Servicing Includes

Maintenance technicians will follow a furnace inspection checklist to cover all the important elements. Here are some things you can expect from a typical furnace inspection and cleaning.

• Checking the thermostat settings to make sure the system is properly running

• Inspecting electrical connections and testing the voltage on the system components to prevent any component failure in the future

• Lubricating moving parts

• Inspecting the condensate drain for obstruction

What Should I Look for When Hiring an HVAC Technician?

Experience is everything when it comes to hiring an HVAC technician near you. Above all, you’ll want a pro who knows how to handle your type of furnace so they can properly diagnose and fix the issue(s). Not all states require HVAC technicians to be licensed, but if your state does, you might want to verify their license for peace of mind using our handy state contractor license tool.

Lastly, ask around for recommendations from family and friends. If no good leads come up, check out the Better Business Bureau to see ratings for HVAC companies in your area.

What Other Benefits Come With Furnace Servicing?

It’s beneficial to have your furnace serviced regularly even if it’s running smoothly. A well-maintained appliance has a better chance of continuous operation than one that has fallen into disrepair. While you can easily change the air filter on your own every three months, your HVAC tech can clean out everything else, as well as notice any cracks or damaged parts that need to be repaired or replaced.

If you have a new(er) furnace, you’re likely still under warranty, and you’ll need to show proof of a regular service schedule should you need to make a claim.

Paul F. P. Pogue contributed to this piece.