Furnace Tune-Up Before Winter: What a Checkup Covers, What You Can Do, and How to Hire an HVAC Technician

Why and When to Get a Furnace Check-Up

Having your furnace checked before winter helps ensure it runs safely and efficiently. ENERGY STAR advises getting an annual pre-season check-up for your heating system, ideally in the fall. This is because heating and cooling contractors get very busy once summer and winter arrive. A thorough check-up can help prevent issues before they become bigger problems.

What a Technician Does During a Check-Up:

According to ENERGY STAR, a typical check-up for your heating system includes:

• Checking thermostat settings.
• Tightening all electrical connections and measuring voltage and current on motors. Faulty electrical connections can make your system unsafe.
• Lubricating moving parts.
• Checking the system’s controls and starting cycle.
• Checking all gas connections, gas pressure, burner combustion and the heat exchanger. Gas connections that do not work properly are a fire hazard and can cause health problems. A dirty burner or a cracked heat exchanger can make the equipment run less safely and efficiently.

Modern furnaces, especially high-efficiency models, are more complex than older ones. They use electronic controls to balance fuel, air for burning (combustion air), and exhaust gases. These controls need regular adjustment and cleaning for the best performance. The Minnesota Department of Commerce states that an annual clean and tune keeps these systems properly adjusted and can reduce expensive repairs later.

What a Qualified Technician Should Do (Minnesota Department of Commerce):

• Check the igniter and flame sensor.
• Pull and clean the burners.
• Inspect the heat exchanger for too much rust or cracks.
• Blow out the condensate line on high-efficiency models. This line drains water that forms during operation.
• Check the system’s static pressure.
• Do a combustion analysis.
• Check the gas pressure.
• Check for gas or venting leaks.
• Inspect and lubricate the blower motor.

What You Can Do Between Technician Visits

You can do several things to help your furnace run efficiently and safely between professional check-ups. These steps can improve performance and help keep you safe.

Homeowner Furnace Checklist:

• Replace the furnace filter: A clogged filter blocks airflow. This makes your furnace work harder and longer to heat your home. Check your furnace manufacturer’s instructions for the right filter type and how often to change it.
• Check the condensate drain line: If you have a high-efficiency furnace, it creates water. This water drains through a line. If this line gets plugged, your furnace might not work right or could even shut down. Check this line for blockages each time you change your filter.
• Clear outside intake and exhaust pipes: Some furnaces have plastic pipes that go through the side of your house to bring in fresh air and let out exhaust gases. If these pipes are blocked by insect or animal nests, leaves, or snow, your furnace might shut down. Partial blockages can also lead to poor performance or dangerous conditions. Check these pipes regularly.
• Inspect chimneys: If your furnace exhausts through a chimney, it should be checked every year. Look for blockages and make sure the bricks, mortar, and flashing (the material that seals the chimney to the roof) are in good condition.
• Install carbon monoxide alarms: The U.S. Consumer Product Safety Commission (CPSC) advises placing battery-operated carbon monoxide (CO) alarms, or alarms with battery backup, on every level of your home and outside sleeping areas. Carbon monoxide is an invisible, odorless gas that can be very dangerous.
• Know carbon monoxide warning signs: The Minnesota Department of Commerce explains that if burning by-products are not vented outside properly, it can create unhealthy conditions, including carbon monoxide. Symptoms of CO poisoning can feel like the flu or a cold: headache, nausea, irritated eyes and nose, and later, confusion and tiredness. These symptoms might get better when you leave your home. Moisture buildup in your house, especially condensation on cooler windows, can also be a sign.

Causes of Carbon Monoxide (Minnesota Department of Commerce):

Many CO problems come from issues with venting flue gases (exhaust gases), such as:

• A cracked furnace heat exchanger.
• Blocked or too-small chimneys or vents.
• Damaged or separated vents.
• Not enough fresh air for burning fuel.

To keep your family safe, the Minnesota Department of Commerce recommends annual inspections that include a CO test for all devices that burn fuel, like your furnace, water heater, fireplace, dryer, and range.

Important: Anything involving your furnace’s gas lines, burners, venting, or wiring is a job for a qualified professional technician. Do not attempt to work on these parts yourself.

Hiring a Heating Technician and Understanding Duct Cleaning

When it’s time to hire a professional for your furnace, it’s good to know what to look for and what services you might not need.

About Air Duct Cleaning:

The U.S. Environmental Protection Agency (EPA) does not recommend routine air duct cleaning. It suggests cleaning only when needed, as the benefits are uncertain in most cases. Duct cleaning has not been proven to prevent health problems, and a small amount of household dust in ducts is normal. Duct cleaning is not part of the yearly maintenance for your heating and cooling system, which includes regular cleaning of drain pans and coils, filter changes, and yearly furnace inspections.

When the EPA Suggests Considering Duct Cleaning:

• If you see a lot of mold growth inside hard-surface ducts or on other parts of your heating and cooling system.
• If rodents or insects have infested your ducts.
• If your ducts are clogged with too much dust and debris, or if particles are coming out of your supply registers into your home.

EPA Warnings About Duct Cleaners:

If you consider duct cleaning, talk to several service providers and get written estimates. Ask them to show you the contamination that makes cleaning necessary. Be cautious of companies that:

• Make broad claims about health benefits.
• Recommend duct cleaning as a routine part of maintenance.
• Claim to be certified by the EPA. The EPA does not certify, endorse, or approve duct cleaning companies.
• Suggest chemical biocides or treatments without fully explaining the pros and cons.

Check references and ask if the provider has relevant state licenses. Get a written agreement that shows the total cost and what work will be done before they start.

Tips for Hiring a Heating Technician:

Finding a qualified professional is key to proper furnace maintenance and any necessary repairs. ENERGY STAR offers these tips:

• Check licenses and insurance: Find out about the license and insurance requirements for contractors in your state. The Federal Trade Commission (FTC) advises only considering licensed and insured contractors. You can confirm a contractor’s license with your state or county government and ask for proof of insurance.
• Know your system: Before you call, know your current furnace’s model and its maintenance history. Also, note any rooms that feel uncomfortable.
• Ask for referrals: Ask friends, neighbors, and co-workers if they have recommendations.
• Check references: Ask contractors for customer references and call them. Ask about their experience with the contractor’s work and if the job was finished on time and within budget.

When This Advice May Not Fit

This advice is for general furnace maintenance and hiring a qualified technician. If you smell gas, suspect a carbon monoxide leak, or have a complete furnace breakdown during cold weather, these are urgent situations. For gas smells, leave the house immediately and contact your gas company from a safe location. For suspected CO leaks or no heat in winter, contact a qualified professional right away. If you are dealing with a furnace that is still under warranty, contact the manufacturer or the installer first, as specific procedures may apply.