Posted: February 3, 2025

How to Replace a Furnace Filter

A Step-by-Step Guide

Replacing your furnace filter is one of the simplest and most effective ways to maintain your heating system and improve indoor air quality. Regularly changing the filter helps your furnace run efficiently, prevents breakdowns, and keeps the air in your home clean. Follow the step-by-step guide below to replace your furnace filter like a pro.

• Step 1: Turn off the furnace. Safety comes first. Before you start, turn off the furnace to avoid accidental operation while you’re working. You can do this by switching the thermostat to the “off” position or turning off the power to the furnace at the breaker.
• Step 2: Locate the filter. The furnace filter is typically found in the blower compartment, near where the return air duct enters the furnace. It might also be in a slot on the side, bottom, or back of the unit. Refer to your furnace manual if you’re unsure of its location.
• Step 3: Determine the filter size. Check the size of your existing filter before removing it. The dimensions are usually printed on the side of the filter (e.g., 16 x 25 x 1). If the size isn’t visible, measure the filter’s length, width, and thickness. Buying the correct size is crucial for proper operation.
• Step 4: Remove the old filter. Carefully slide the old filter out of its slot. Take note of the direction of the arrows on the filter frame, which indicate the airflow direction. This will help you install the new filter correctly.
• Step 5: Inspect the old filter. Examine the old filter to see how dirty it is. If it’s covered in dust and debris, replacing it was overdue. Regular replacement intervals vary, but a good rule of thumb is every 1–3 months, depending on usage and the type of filter.
• Step 6: Install the new filter. Insert the new filter into the slot, ensuring the airflow arrows point in the correct direction—toward the furnace. Push it securely into place but avoid forcing it.
• Step 7: Turn the furnace back on. Once the new filter is installed, turn the power back on and set your thermostat to the desired temperature.
• Step 8: Schedule regular replacements. Mark your calendar or set reminders to check and replace the filter as needed. Doing so will keep your furnace running efficiently and prolong its lifespan.

Replacing your furnace filter is an easy task that delivers significant benefits. By keeping up with this simple maintenance routine, you’ll ensure cleaner air, lower energy bills, and a more reliable heating system. Make it a habit, and your furnace—and your wallet—will thank you!

Professional Furnace Maintenance

While replacing your furnace’s filter is something you can do yourself, you should also invest in professional maintenance for your furnace at least once a year. Ace-Robbins offers comprehensive heating tune-ups that will bolster your heating system’s efficiency, lower the chance of breakdowns, and extend the life span of your equipment. It’s an investment in lower energy costs and more dependable home comfort in the winter.

As part of the maintenance visit, our technicians will inspect your system’s burners, lubricate mechanical parts, check and tighten connections, and test and calibrate components and settings. We’ll also repair any issues we find before they can cause your system to falter or break down.

For total peace of mind, consider protecting your heating equipment with one of our Maintenance Plans. This coverage includes a complimentary annual tune-up and lowers your repair costs.

Contact Ace-Robbins today for all your furnace needs. You can count on us!