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.
⭐️⭐️⭐️⭐️⭐️ 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.
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.
Giovanni the service technician was the best! Very knowledgeable, efficient and did a professional job replacing my hot water heater. I would highly recommend them to anyone in need of plumbing/ HVAC work first rate customer service at a very competitive price!
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!
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.
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!
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.
I'm a new customer and had my first appointment for furnace check.My tech was Zack and what a professional. He explained how he checked system and answered all my questions. This was a very good experience
Response from the owner:Thank you, Patricia, for your kind words! We're glad to hear that Zack provided you with a professional and informative experience during your furnace check. Your satisfaction means a lot to us!
Thomas Hoffman is a wonderful company to work with. Techs are knowledgeable, personable & efficient.
Response from the owner:Thank you, Christine, for your kind words about our team; we appreciate your feedback and are glad to hear you had a positive experience!
I called on December 25th at midnight and started leaving a message and Thomas Hoffman the owner called me back almost immediately. He said he would come out the next morning between 8:00 and 10:00 am snd he was promptly on time. He fixed my problem and while he was there I decided to get an estimate for a new furnace and air conditioning unit. The price was very reasonable and the installers one of them being his son were both very professional very courteous, polite, arrived on time and finished the same day. I enjoy knowing that I now have the support of Thomas Hoffman heating and air conditioning along with the peace of mind that comes with owning a Trane. Nothing stops a Trane.
Albert Koesterer
Response from the owner:Albert thanks so much for your kind reviews and your business. We truly appreciate it!!!
The Thomas Hoffmann team did a great job taking care of our semi annual HVAC maintenance. They not only worked with us to schedule the visit, but also did an excellent job sending us reminders on when they would be out.
Response from the owner:Thank you so much for the great review, Bob! We appreciate your support and are happy to hear you had a great experience!
Nick was excellent. Super profession, quick, and up front with the pricing (which was fair). Hopefully we don't need to call anyone to fix our AC again, but if we do - I'm calling Nick!
Response from the owner:Thank you, Layton, for your amazing review! We really appreciate your support and hope to be your first call for any future repairs!
Same day service. Technician arrived as scheduled. Replaced capacitor quickly. Friendly technician. Repair cost $429 seemed high for inexpensive part and 20 minutes labor.
Response from the owner:Thank you, Tom, for your feedback! We're glad to hear the technician was prompt and friendly, though we understand your concerns about the repair cost. We appreciate your insights and hope to serve you again in the future.
Response from the owner:Thank you so much, Al, for your excellent review; we truly appreciate your support and are glad to hear you had a great experience!
Thomas Hoffmann is the most professional and courteous of all the HVAC companies in St. Louis. It has kept my HVAC systems in good working order through the hottest and coldest days for many years.
Response from the owner:Thank you, Jonathan, for your kind words about our professionalism and courtesy; we truly appreciate your support!
I notified two companies at the same time regarding a malfunctioning AC unit and Wow! Super fast response from Hoffmann on a weekend no less, to fix our AC unit. Hoffmann’s tech responded to my call immediately and fixed our AC before Galmiche has even responded. Used to be a Galmiche customer, but will use Thomas Hoffmann from here on out!
Response from the owner:Thank you, Darlene, for your fantastic feedback! We're glad to hear that our team was able to respond quickly and resolve your AC issue. We appreciate your trust in us moving forward!
Ryan did a great job with my AC reinstall. Very knowledgeable company with Tom Hoffmann providing the engineering expertise.
Response from the owner:Thank you, Steve! We're glad to hear that Ryan did a great job on your AC reinstall, and we appreciate the shoutout to Tom's expertise. Your satisfaction means a lot to us!
These guy's are amazing same day service very well priced for the knowledge they have ask before doing anything to confirm they're my new go to
Response from the owner:Thank you, Cory! We're glad you found our service amazing and appreciate your kind words about our pricing and knowledge. We're here for you anytime!
They came very fast to fix our AC and service was very good
Response from the owner:Thank you, Maria, for your kind words about our service; we're glad to hear you had a great experience!
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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