Wondering if it’s time to replace your air filter? Here are five signs it might be time to make a change. Contact us today.
At Thomas Hoffmann Air Conditioning & Heating, we often remind homeowners that the humble air filter plays a massive role in the overall health of your HVAC system — and your indoor air quality. A dirty or worn-out air filter can lead to reduced efficiency, higher energy bills, and even system breakdowns. Yet, it’s an often-overlooked part of routine maintenance. So, how do you know when it’s time to swap out your air filter? Here are five key signs you shouldn’t ignore.
The technician, Ryan, was knowledgeable and helpful in identifying the issue with our mini split AC unit. They are the second company we called after issues with the first and will be using Hoffmann again.
woke up to a very cold house, called Thomas Hoffmann, they were able to come out a couple of hours later and get the issue resolved. Always trust them, they have always been quick to respond and get either the heating or ac issue fixed that day. Also a great price!!!! give them 10 stars if i could, Thank You JS
Response from the owner:Thank you for the kind review, Jim. We are happy to hear that you had a positive experience working with Thomas Hoffmann!
Response from the owner:Thank you, Hank, for your wonderful feedback; we're glad you enjoyed the fast, friendly, and professional service, and we'll be sure to keep up the great work!
The technician Giovanni was excellent and on time very professional and efficient and knowledgeable of the project at hand ,gave great advice but most of all did great work 👏 thank you .
Response from the owner:We are so happy to hear you had a great experience, Sam! Thank you for the review, and thank you for your business.
Your service technician was very professional and knowledgeable. And did not appear to try to give me bogus information. I truly appreciate his honesty because several other companies did not appear to be honest, obviously wasn’t honest, my gut feeling told me they were not honest and tried to get me to spend $10,000 for a problem that was much simpler to fix. I look forward to you servicing all my properties, and possibly those of the rest of my family.
Response from the owner:Thank you so much for the kind words and great review! We appreciate your support.
Very prompt, communication was great, and the workers were very polite. I highly recommend them!
Response from the owner:Thank you, Lianne! We're glad to hear that you had a positive experience with our team and appreciate your high recommendation.
Water heater repaired, appointment done the same day, effective, courteous
Response from the owner:Thank you, Leticia! We appreciate your kind words and are glad to hear that the water heater was repaired promptly and effectively. Your satisfaction means a lot to us!
The service tech Giovanni did a fantastic job. Our gas fireplace is working like new again so we’re ready for the cold weather!
Response from the owner:Thank you, Mr, for your fantastic review! We're glad to hear Giovanni provided you with excellent service and professionalism. Your recommendation means a lot to us!
⭐️⭐️⭐️⭐️⭐️ If I could give 10 stars, I absolutely would.
Last night our furnace went out unexpectedly, and with three kids in the house, the temperature dropped fast. Giovanni went above and beyond in every way possible. Instead of charging me a late-night service fee, he simply asked, “Are you decently handy?” and offered to walk me through some troubleshooting steps to get our heat back on so my children wouldn’t have to sleep in the cold.
Not only did he guide me through the process, he even FaceTimed me and showed me exactly what to take apart, how to put it back together, and what signals to watch for. It felt like having a real technician standing right next to me the entire time. Thanks to him, our heat was restored within minutes.
In a world where true customer service is hard to come by, Giovanni is a rare find. It is a guaranteed fact that any future repairs, maintenance, and the new heater/AC system we’ll be needing this coming summer/fall will absolutely be done through him. His honesty, kindness, and expertise have earned our business for life.
Highly, highly recommend.
Response from the owner:Thank you, Jeff, for sharing your experience! We're so glad to hear Giovanni was able to help you and your family during that tough situation. Your recommendation means a lot to us, and we appreciate your trust in our services for the future!
My neighbor referred these guys to me when had water heater problem. Previous company told me I needed to replace it. Tom’s technician fixed it for less than $200. This was over 2 years ago and have been using their service ever since. They are very trustworthy.
Response from the owner:Thank you, Mary, for sharing your experience and for trusting us with your water heater issue; we're glad our technician could help and that you've continued to rely on our services!
I called this company earlier today because I was having a bunch of issues with my HVAC system. They were incredibly friendly and walked me through troubleshooting step by step over the phone. They didn’t even charge me for the call. Thanks to their honest advice, I was able to get things running smoothly again. Really grateful for their help and would definitely recommend them if you want straightforward and trustworthy service. Five stars all the way!
Response from the owner:Thank you so much for the glowing review, Hector! We appreciate your business and look forward to working with you in the future.
Nick did not set current time. — Monday Hoffmans Zach came to fix correct time. We DID NOT want a timed thermostat — we prefer to set temperatures manually
Response from the owner:Thank you, Pat, for your kind words about Giovanni; we appreciate your feedback and are glad to hear that he made a positive impression.
Clear communication about arrival, service and costs.
Response from the owner:Thank you, Margaret, for your kind words! We appreciate your feedback on our clear communication and are glad you had a positive experience.
I will highly recommend this business for your air and heater repair. Prompt, knowledgeable and courteous service.
Response from the owner:Thank you, Judy, for your kind words and recommendation! We're glad to hear you were pleased with our prompt and courteous service.
Thomas Hoffman was very responsive to our after hours inquiry, even walked us through some trouble shooting over the phone. We provided pictures of the unit and they were able to quickly buy, schedule and install the part to keep our family warm!
Response from the owner:Thank you, Ali! We're glad to hear that Thomas was responsive and helpful in getting everything sorted out for you and your family. Your feedback means a lot to us!
Nick came by, identified the problem quickly and had it fixed. Great service!
Response from the owner:Thank you, Ted! We're glad to hear that Nick provided you with quick and effective service. Your feedback is greatly appreciated!
Great service. Responsive. Well trained technicians. Honest friendly and thorough. I highly recommend Tom Hoffmann and his team.
Response from the owner:Thank you for your kind words! We appreciate your recommendation and are delighted to hear about your positive experience with our team.
Ryan Taylor with Thomas Hoffman did an outstanding job in servicing our unit & explaining everything to me, especially how our humidifier worked, since we were new home owners & had not had one before. Thank you!
Response from the owner:Thank you! We're glad to hear that Ryan and Thomas provided you with excellent service and helped you understand your new humidifier. We appreciate your feedback!
As always, the Hoffmann technician Zach was polite, professional, and efficient. Pricing is reasonable and even more importantly, they are dependable. I will continue to use Thomas Hoffman A/C and Heating.
Response from the owner:Thank you, Mark, for your kind words about our technician and for your continued trust in Thomas Hoffman A/C and Heating; we truly appreciate your support!
Response from the owner:Thank you, Brandon! We appreciate your kind words and are glad to hear about your positive experience with Hoffmann’s professionalism and thoroughness.
Our service technician arrived right on time and was professional, friendly, efficient and courteous. We couldn’t ask for more.
Response from the owner:Thank you for sharing your positive experience with our service technician! We appreciate your kind words and are glad to hear that you were satisfied with the service provided.
Ryan was here on time. Thanks for getting here early, as I requested. Very friendly too. It was my annual checkup and all good!
Response from the owner:Thank you so much for the great review, Kay. We truly appreciate your business!
1. Your Energy Bills Are Rising Unexpectedly
If your energy bills are creeping up and there’s no obvious explanation, your air filter could be the culprit. A clogged filter forces your HVAC system to work harder to maintain your desired temperature, leading to increased energy consumption. Simply replacing a dirty filter can reduce your system’s energy use by up to 15%!
Pro Tip: Keep an eye on your monthly utility bills. A sudden spike could be your first clue that maintenance is overdue.
2. Your Home is Dustier Than Usual
Notice a fine layer of dust settling just days after you’ve cleaned? A dirty air filter can’t trap airborne particles effectively, meaning more dust, allergens, and pollutants circulate through your home. If your furniture, vents, and baseboards seem perpetually dusty, it’s time to check the filter.
Bonus Benefit: Regular filter changes not only help your HVAC system but also reduce your household cleaning chores!
3. Your HVAC System is Running Longer or Short-Cycling
An air filter clogged with debris can restrict airflow, causing your system to work overtime or short cycle (turn on and off rapidly). Both scenarios strain the HVAC components and can lead to premature breakdowns. If your furnace or AC is behaving oddly, your first step should be a simple filter inspection.
Warning: Ignoring this sign could lead to costly repairs down the road. Filters are cheap — replacing compressors and motors is not!
4. You Notice a Decline in Indoor Air Quality
Are you sneezing more indoors? Is there a persistent musty smell? Poor air quality is a significant indicator that your filter isn’t doing its job. This is especially critical for homes with pets, smokers, or residents with allergies or respiratory conditions. A fresh air filter can make a remarkable difference in breathing comfort.
Local Note: Here in St. Louis, spring and fall allergy seasons are tough enough without adding a dirty air filter into the mix.
5. You Can’t Remember the Last Time You Replaced It
If you’re scratching your head trying to recall when you last swapped out your air filter, chances are it’s overdue. As a general rule of thumb:
Every 1-2 months for homes with pets or allergy sufferers.
Every 2-3 months for typical suburban households.
Monthly, during peak heating and cooling seasons.
Pro Tip: Set a recurring reminder on your phone or calendar to inspect your filter monthly.
Why Regular Air Filter Changes Matter
Replacing your air filter regularly isn’t just about saving money (though it certainly helps). It’s about protecting your family’s health, extending the life of your HVAC system, and ensuring your home stays comfortable year-round.
Contact Thomas Hoffmann Air Conditioning & Heating Today
At Thomas Hoffmann Air Conditioning & Heating, we make HVAC maintenance simple. Whether you need a quick filter change, a complete system tune-up, or expert advice, our locally-owned team is here to help — with honest pricing, friendly service, and decades of St. Louis know-how.
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