24/7 Emergency Service (314) 471-7625

Common HVAC Smells and What They Mean: A St. Louis Homeowner’s Guide

Published:

As a homeowner in St. Louis, you rely on your HVAC system to stay comfortable year-round.

But what happens when your heating or cooling system starts emitting unusual odors? At Thomas Hoffmann Air Conditioning & Heating, we understand that strange smells from your HVAC can be concerning.

In this article, we’ll explore common HVAC odors, what they might mean, and when it’s time to call in the professionals.

Common HVAC Smells and What They Mean
Zac did our service today. A very professional and courteous young man.
He did a thorough inspection and cleaning on our HVAC system.
Response from the owner:Thank you, Tom, for your kind words about Zac's professionalism and thoroughness during your HVAC service; we appreciate your feedback!
I've used these guys twice now and their response time is great, they are friendly, informative, and most importantly, effective. I'm calling these folks every time my furnace sounds weird.
Response from the owner:Thank you for the wonderful feedback, Greg! We're glad to hear that you've had such positive experiences with our team. Providing timely and effective service is our priority, and we're here whenever you need us. Looking forward to assisting you again!
Excellent place to work with and installation crew were A+. They were able to get my new AC and Furnace installed quickly. I have breathing issues and disabled so this was a GREAT experience. If you need AC or Furnace installed this is your place.
Response from the owner:Thank you, Tony, for your wonderful feedback! We're glad to hear that our installation crew made the process smooth and efficient for you. Your satisfaction means a lot to us, and we appreciate your recommendation!
Fast, super friendly, and reasonable prices keep us coming back.
Response from the owner:Thank you! We're so glad to hear that our speed, friendliness, and prices keep you coming back. We appreciate your support!
Zachary was very friendly, efficient and knowledgable. He was able to service both units in 1 hour. I would recommend Thomas Hoffmann A/C for any future needs for me.
Response from the owner:Thank you, Michael! We're glad to hear that Zachary provided you with friendly and efficient service. We appreciate your recommendation and look forward to assisting you with any future needs.
Great service and went the extra mile for us . We would most definitely use them again
Response from the owner:Thank you, Andre, for your kind words and for recognizing our efforts; we can't wait to serve you again!
Thomas Hoffman air-conditioning and heating is so wonderful and professional! Nick Hoffman was the technician that diagnosed my malfunctioning air conditioning system and determined how to fix it. He was so incredibly professional and even invited me to watch while he worked, and kindly explaining to me all the details about the problem and how he is fixing it. I am now a client for life with this company because of how professional, knowledgeable, and a delight to work with they are! I want to add that they prioritized helping me on the same day that I called and even was a holiday (and 90 degree heat out!), so that is another outstanding Effort from this amazing company! Thank you so much.
Response from the owner:Thank you, Carrie, for your wonderful feedback! We're delighted to hear about your positive experience with Nick and our team. Your satisfaction is our priority, and we're glad we could assist you on the same day. Welcome to our family of clients!
They were able to come out quickly to help when our AC went down in the heat! They were prompt, kind, knowleadgable, explained everything easily in ways I could understand, fixed the issue, and made the experience so easy! I felt comfortable with the technican in and around our home working. Nick took the time to answer some questions about an unrlated issue while there. They will always be who we call for our heating and cooling needs!
Response from the owner:Thank you, Erin, for your wonderful feedback! We're glad to hear that our team, especially Nick, was able to assist you promptly and make the experience comfortable and easy. Your trust in us for your heating and cooling needs means a lot!
I highly recommend Thomas Hoffmann for anything involving HVAC. The person replacing my furnace, Britton Buehrig, was Professional and took pride in his work. The job was very cleanly done.
Response from the owner:Thank you, Ray, for your kind words and recommendation! We're glad to hear that you were provided with professional service and a clean installation. Your satisfaction means a lot to us.
Excellent service. AC went out on a hot summer day, hooked up with them through Angi, and within 2 hours they had arrived and fixed the problem. Can't ask for more than that
Response from the owner:Thank you for your kind words! We're glad we could help you quickly on that hot summer day. Your satisfaction means a lot to us!
Nick Hoffman was great. He came short notice to fix a leaky air handler did it quickly and efficiently and also took a look at the AC plan on using them again for our service of our HVAC
Response from the owner:Thank you, Jenny, for your kind words about Nick and for trusting us with your HVAC needs; we're glad to hear he was able to assist you efficiently!
Super company to deal with. Always professional, knowledgeable and friendly. Zachery was my technician and explained everything he did throughly and in a manner I could understand. Very nice guy.
Response from the owner:Thank you, Maggie, for your kind words! We're glad to hear that Zachary provided you with excellent service and clear explanations. We appreciate your support and look forward to helping you again!
My a/c was not working correctly and I knew it needed to be serviced. The person came and cleaned what needed to be cleaned and he did what he could for the output. He was very professional and nice. We will definitely call them for our future needs.
Response from the owner:Thank you for the positive feedback! We're glad to hear that you were pleased with our prompt and friendly service. We look forward to assisting you again in the future!
Great service
Response from the owner:Thank you so much for your kind words! We're grateful for your support and delighted to hear you had a great experience.
Nick arrived to repair our ac earlier than expected. He quickly diagnosed and made the necessary repairs. The cost was reasonable. We will definitely contact Thomas Hoffmann for hvac services in the future..
Response from the owner:Thank you, Michael! We're glad to hear Nick provided prompt and efficient service, and we appreciate your trust in Thomas Hoffmann for your future HVAC needs.
We have used Thomas Hoffman Air Conditioning and Heating for AC issues for the last two years. We have been so happy with the service we have received both times. This year, we just needed a little maintenance as our unit wasn’t working to its full potential. I called first thing in the morning and was able to get a same day appointment! Nick was so personable and knowledgeable, and he got us back up and running and no time. Thank you again for saving us from the summer heat!! We are so grateful for the amazing customer service you guys provide!!!
Response from the owner:Thank you so much, Teri, for your kind words and for trusting us with your AC needs over the past two years; we're glad Nick could help get your unit back to its best, and we truly appreciate your gratitude for our service!
I txt Thomas Hoffman air-conditioning and heating Sunday early evening about 6:30 and just left A detailed message of what was going on with my AC I received an automated reply, saying they would contact me soon. I heard from them the next Morning at 11 AM to confirm what was going on with my unit and said they would have a Tech out today still but would be the last call between 6 and 8pm. I expected to get an appointment 2 to 3 days later. We’re in the middle of about an 8 to 10 day Heat wave of Mid to upper 90s. So imagine my surprise when I received a call from Zachary at 3:20 telling me he was in Saint Charles and was on his way to my house to look at the unit. When I explained what was wrong on the phone, he was pretty confident. He knew what it was once he got here, pulled off the cover and sure enough it was the capacitor. Pull the old one off and install the new one turned it back on and boom I have cold air blowing. I would highly recommend Thomas Hoffman, AC and heating and if you can request a certain Tech Zachary is your guy he is great super Frndly got the job done quickly and even interacted with my dogs Who are super friendly
Response from the owner:Thank you, Vicki, for sharing your experience with us! We're glad to hear that Zachary was able to resolve your AC issue quickly and that he made a positive impression on both you and your dogs. We truly appreciate your recommendation and look forward to assisting you again!
We can’t say how happy we are with the quick and efficient service! We came home Friday evening after work on a 95 degree day (with a week of 90 degree weather ahead) and our A/C was totally out. We called this small business owner around 6pm and he was here by 7:25. He replaced our wires, had cool air running, gave us some helpful tips for the future, and was already out the door by 7:50. He was very polite, friendly, straightforward, and saved our evening/weekend!
Response from the owner:Thank you, Morgan, for your wonderful feedback! We're glad our team could provide quick and efficient service to keep you comfortable during the heat. Your satisfaction means a lot to us!
Giovanni was so great. Explained things so I understood. He is kind. I appreciated him cleaning up and being so nice. Thank you.
Response from the owner:Thank you, Peggy! We're so glad to hear Giovanni made your experience enjoyable and that his kindness stood out to you. Your appreciation means a lot to us!
Tom & Nick have taken care of all our HVAC needs for multiple properties for over a decade. Great team.
Response from the owner:Thank you, Kurt, for your kind words; we're grateful for your continued trust in our business for your HVAC needs over the years!
We recently moved into an older home and had an issue with the AC not working. We called and were offered a same-day appointment. Nick was fantastic—very knowledgeable and professional. He quickly diagnosed the issue with the air handler and got it fixed, and also installed a new thermostat for us. He was honest and straightforward with his recommendations and never pushed unnecessary products. Highly recommend!
Response from the owner:Thank you, Adriana, for your wonderful feedback! We're glad to hear Nick was able to help you with your AC issue and provide excellent service. Your recommendation means a lot to us!
Zach worked fast and answered all my questions with ease.
Response from the owner:Thank you, Stephanie! We're glad to hear that Zach provided you with quick and helpful answers.
Thomas Hoffman replaced my water heater. They were effective, efficient and pleasant people with whom to work.
Response from the owner:Thank you, David, for your kind words about Thomas and the team; we appreciate your feedback and are glad you had a positive experience with your water heater replacement.
Nick was a true expert in explaining our options for a new thermostat.
Response from the owner:Thank you, Robert, for your kind words about Nick's expertise; we're glad he could help you with your thermostat options!
Responsive! Came over, even after hours to help resolve a critical issue that was caused by a lightning strike causing a gas leak. Would highly recommend!!
Response from the owner:Thank you for your kind words! We're glad our team was able to assist you promptly, especially during such a critical situation. Your recommendation means a lot to us!
Having Tom come to our aid was a great experience and he offered followup assistance with the fancy technology part of the appliance if we need it. We will call him again if the need arises. Merry Christmas.
Response from the owner:Thank you, Marilyn! We're glad to hear that Nick was able to assist you and provide follow-up support. We appreciate your trust in us and wish you a Merry Christmas!
They got the job done, we're very quick and very kind!
Response from the owner:Thank you for your kind words! We appreciate your feedback and are glad we could assist you efficiently.
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.
As always, the Hoffmann technician 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!
These guys are pros.
Techs are friendly, listen and explain what they are doing.
Office staff is responsive.
Fast service....
Response from the owner:Thank you, Clark, for your kind words! We're glad to hear our techs and office staff made your experience a great one. Your feedback means a lot to us!
Excellent service. A/C went out on a weekend. Called them on Saturday morning, they were out within about 2 hours. The fix was easy enough, and he even had the part in the truck! I recommend this company for all of your HVAC needs
Response from the owner:Thank you, Elaine! We're glad to hear you received prompt service and that the fix was smooth. Your recommendation means a lot to us!
The service technicians are very courteous and communicate well with the customer. They let you know what, if any, problems are found, the options, and the cost of the repair(s). Quick and efficient.
Response from the owner:Thank you for recognizing our service technicians' courteous and effective communication, we appreciate your feedback!
These guys were great. Quick to return my call. Up front pricing. Great work on the installation. And the installers were nice and friendly. Highly recommend Thomas Hoffmann.
Response from the owner:Thank you, Steve! We truly appreciate your kind words and are glad to hear you had such a positive experience with our team and Thomas Hoffmann. Your recommendation means a lot to us!
Hoffmann came out the same day I called them because our AC was out. The technician, Ryan, was able to get the system running again, was polite and responded to my questions. We’re off to a good start!
Response from the owner:Thank you, John! We're glad to hear Ryan was able to help and that you’re off to a good start with your AC. We appreciate your feedback!
Thomas came over promptly I spoke with him about my concerns with my unit. Immediately got to work trouble shooting and resolved my issues. A+
Response from the owner:Thank you, James, for your kind words and for recognizing Thomas's promptness and dedication in resolving your concerns; we appreciate your feedback!
We have called Thomas Hoffmann many times and they are very prompt and very professional.
Response from the owner:Thank you, Vicki, for your kind words about Thomas Hoffmann's promptness and professionalism; we truly appreciate your feedback!
Super friendly, helpful, and quick to make the fix.
Response from the owner:Thank you, Jack! We're glad to hear you found our service friendly and efficient; your feedback means a lot to us!

Musty or Moldy Smell

If you notice a musty or moldy odor when your air conditioner runs, it could indicate the presence of mold or mildew in your system. St. Louis’s humid summers create an ideal environment for mold growth, especially in air conditioning units. This smell often results from:

  1. Clogged condensate drain lines
  2. Excess moisture in the evaporator coil
  3. Dirty air filters

Not only is this smell unpleasant, but it can also pose health risks, especially for those with allergies or respiratory issues. Regular maintenance, including changing air filters and cleaning drain lines, can help prevent mold growth.

Burning or Electrical Smell

A burning odor from your HVAC system should never be ignored. This smell could indicate:

  1. Overheating motor
  2. Frayed wires
  3. Burning plastic components

If you detect a burning smell, turn off your system immediately and call a professional HVAC technician. Continuing to run the system could lead to further damage or even pose a fire hazard.

Rotten Egg Smell

A rotten egg smell is often associated with a natural gas leak. While natural gas is odorless, utility companies add a sulfur-like scent to help detect leaks. If you smell this:

  1. Turn off your HVAC system
  2. Open windows for ventilation
  3. Leave your home immediately
  4. Contact your gas company or emergency services

Never ignore a potential gas leak, as it can be extremely dangerous.

Yes, it’s an actual term in the HVAC industry! If your air conditioner emits an odor similar to dirty socks, it’s likely due to bacteria growing on the evaporator coil. This smell is particularly common in St. Louis during spring and fall when the AC runs less frequently. A professional cleaning of your evaporator coil can usually resolve this issue.

Chemical or Sweet Smell

A sweet, chemical odor could indicate a refrigerant leak in your air conditioning system. Refrigerant is crucial for your AC’s cooling process, and a leak can lead to:

  1. Reduced cooling efficiency
  2. Higher energy bills
  3. Potential health hazards

If you suspect a refrigerant leak, immediately turn off your AC and contact a certified HVAC technician.

Dusty or Burning Smell When Heat Turns On

It’s common to notice a dusty or slightly burning smell when you first turn on your furnace after months of disuse. This is typically due to dust accumulation on heating elements and should dissipate quickly. However, if the smell persists or becomes stronger, it could indicate:

  1. A clogged air filter
  2. Debris in the ducts
  3. An overheating component

A professional should check your system if the smell doesn’t go away after a day or two.

An odor similar to gunpowder often indicates an electrical problem, such as a failing fan motor or circuit board. This smell requires immediate attention from a qualified HVAC technician to prevent further damage or potential safety hazards.

Prevention and Maintenance

Regular HVAC maintenance is key to preventing many of these odor issues. At Thomas Hoffmann Air Conditioning & Heating, we recommend:

  1. Changing air filters regularly
  2. Scheduling annual professional maintenance
  3. Keeping your outdoor unit clean and free of debris
  4. Addressing any unusual smells promptly

By staying proactive with your HVAC care, you can ensure a comfortable, odor-free home environment throughout St. Louis’s seasons.

When to Call the Professionals

While some minor odors may resolve independently, it’s always better to err on the side of caution. If you’re experiencing persistent or concerning smells from your HVAC system, don’t hesitate to contact the experts at Thomas Hoffmann Air Conditioning & Heating. Our experienced technicians can diagnose and resolve your HVAC odor issues quickly and efficiently, ensuring your home stays comfortable and safe all year.

Call Now

Remember, a well-maintained HVAC system smells better and operates more efficiently, saving you money on energy bills and preventing costly repairs. Trust your nose – if something doesn’t smell right, it’s time to give us a call!

Leave a Comment