How to Clean Your Furnace: 5 Effective DIY Steps

By: Diana Rodriguez-Zaba
Updated on: February 16, 2024

This time of year, the air takes on a crisp chill, and we finally forget summer’s heat. Still, the deep freeze of winter is just a few weeks away. It’s time to get your home ready for another cold season.

Your DIY handyman talents cover all kinds of cold-weather chores, but do you know how to clean your furnace?

It’s an important annual routine that keeps the house warm and the family safe. While we offer expert furnace cleaning services to Chicago homeowners, it’s a project you can do yourself with a few tools and a little patience.

DIY Cleaning With Benefits

Most DIY jobs around the house are easier to take care of when you’re motivated. Let’s look at the benefits you enjoy when you know how to clean the furnace.

• Safer furnace operation
• Fewer repair bills
• Better indoor air quality
• Lower heating costs

Cleaning the furnace also gives you a close look at how its components are holding up to wear and tear. You might catch an easy DIY repair now before it turns into an expensive service call in the middle of a hard freeze.

How To Clean Your Furnace For a Safer, Warmer Winter

Our DIY guide outlines how to clean a furnace by breaking the project down into five steps. Each one covers an important furnace part, but units differ from model to model. Reference your owner’s manual for detailed information about any of these parts. If you can’t find your booklet, most furnace manuals can be purchased online.==

Before you start any of these steps, be sure to switch off your home’s thermostat, disconnect the furnace’s electricity, and shut off its gas supply.

1. Evaporator Coils

Knowing how to clean your furnace starts at the top of the unit with the evaporator coils. Clean coils help maintain fresh air quality throughout the house.

• Access evaporator coils by removing system cabinet cover.
• Use a vacuum brush attachment to clear away dust.
• Spray with mild detergent and warm water mixture.
• Wipe clean with soft cloths, let dry, and replace cover.

2. Furnace Burners

Debris buildup around furnace burners reduces their efficiency and can pose a fire hazard. Cleaning them improves your heater’s gas combustion process, and that helps hold down heating bills.

• Remove metal housing to expose burner chamber.
• Remove burners for full access to chamber interior.
• Sweep bottom of burner chamber with stiff brush.
• Clean chamber walls with damp cloths.
• Brush and wipe down burners, return to chamber, and replace housing.

3. Heat Exchanger

The heat exchanger is usually a block assembly of coils with several chambers. It’s one of the furnace’s most important parts because it heats air circulating through the unit.

• Remove vented cover for access to heat exchanger.
• Clean each block chamber with bristle brush.
• Wipe down coils and chamber interior with soft cloth.
• Finish with narrow vacuum attachment, and replace cover.

4. Blower Motor

A dirty blower motor compromises indoor air quality. Cleaning the motor helps it run efficiently, and that makes it easier for other furnace parts to do their job.

• Remove furnace front panel from supporting hinges.
• Slide out blower motor and release screws or wire connections.
• Clean blower components with mild soap and water mixture.
• Wipe blades and belts with damp cloths, let dry, and vacuum.
• Reattach motor to track, slide into unit, and replace front panel.

5. Furnace Filter

While some filters are inserted behind a grill in the wall or ceiling, others are located on the furnace and even inside the blower compartment. All are easy to replace or clean, and they play a dual role in efficient operation.

Furnace filters reduce airborne contaminants throughout the house, and they help protect equipment from accumulating dust and debris. The three most common types of filters are:

• Fiberglass Filters – Catch large airborne particles; effective if allergies aren’t a problem; inexpensive.
• Pleated Filters – Remove most airborne particles; extra pleats allow better air flow; fairly expensive.
• Electrostatic Filters – Highly efficient and washable; environmentally friendly; expensive, one-time investment.

Making Your DIY Life Easier

It’s always our pleasure to post how-to guides that make your DIY life a little easier. We invite you to join our online community, so let us know how our overview helps you take care of furnace cleaning this season. Share your input through our Comments Section.

If the job seems too big or you don’t have time, we’re just around the corner. As an extension of our air duct and HVAC cleaning, we provide furnace cleaning services for homeowners across Chicago and the suburbs. When you need help getting the house ready for another cold season, ServiceMaster Restoration by Zaba is ready to answer your call.