Is your furnace blowing cold air instead of heat? You deserve to stay warm. Call us today at (314) 471-7625 or visit our contact form.
There’s nothing more frustrating than cranking up the heat on a chilly St. Louis day only to feel cold air blowing from your vents. If your furnace is blowing cold air instead of the cozy warmth you expect, don’t panic. This is a common issue with several potential causes—some of which you can address yourself and others that may require a professional HVAC technician.
Need help now? Contact us today or call us to schedule same-day service.
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!
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!
Not a customer, but witnessed one of their technicians have an episode of road rage in Clayton. I would be concerned about letting them into my house/business.
We really trust Thomas Hoffman AC and Heating. Nick Hoffman has serviced our units several times now and he is professional, knowledgeable and very easy to work with. He comes on time, so we don’t have to schedule a long waiting period. We would highly recommend this company.
Response from the owner:Thank you, Greg, for your kind words and for trusting us with your AC and heating needs; we’re glad to hear that Nick has provided you with such great service.
We’ve been looking for a locally owned small HVAC dealer for a few years. And we found it with Thomas Hoffmann Air Conditioning & Heating. We love their service technicians. They come on time, they know what they are doing, they don’t upsell you on every appointment and they like working for Thomas Hoffmann. A happy employee makes for a happy customer.
Response from the owner:Thank you, Mary, for sharing your wonderful experience with us; we're glad to hear you appreciate our technicians and their commitment to great service!
I called on a Monday morning as air conditioning was blowing warm air. They were able to come to my house very early afternoon and fixed the problem. Would highly recommend and will use them again.
Response from the owner:Becky thank you so much for your great review. We appreciate your business and your kind words.
Response from the owner:Thank you, Margaret! We appreciate your kind words and will make sure to pass along your praise to Nick for his excellent service.
I am very pleased with the service provided. , especially the quick response to my request . The technician came in themorning and had my cooling system repaired within an hour. Thank you !
Response from the owner:We're delighted we could promptly assist you on a Sunday morning and fix your cooling system efficiently. Thank you!
Here on time, worked fast. Always pleasant and great answering questions. Zach always does a great job.
Response from the owner:Thank you, Debra, for your kind words; we're glad to hear Zach made a positive impression and that you had a great experience with our team!
Extremely quick response for appointment and did quick fix for our furnace and heat is working great !
Response from the owner:Thank you for your kind words! We're glad to hear our team was able to respond quickly and get your furnace working great. We appreciate your feedback!
They were timely, polite, professional and they saved us from too much sweating. In a field full of pompous and arrogant technicians, these guys take the time to explain what is wrong and how they are correcting it. Other folks just assume you are incompetent but these folks take the time to educate. Cannot recommend highly enough.
Response from the owner:Thank you for your kind words! We truly appreciate your feedback and are glad we could provide you with a positive experience.
I would like to have a receipt for my payment which I did not receive. On a positive note he was very punctual very early actually he did his job and was very professional and I'm hoping and praying this took care of the issue thank you and I would not hesitate at this time to use your services
Response from the owner:Thank you, Mark, for your feedback and for highlighting the punctuality and professionalism of our team; we appreciate your support and will ensure you receive your receipt promptly.
Our experience with them was fantastic all the way through! Not only were they able to get to our business that day but the customer service from the phone call to the on-site service was professional and quick. We'll definitely be using Thomas Hoffmann Air Conditioning and Heating in the future.
Response from the owner:Thank you, Michelle, for your wonderful feedback! We're glad to hear about your fantastic experience and appreciate your kind words about our team's professionalism. We look forward to serving you again in the future!
I couldn’t be happier with the service from Thomas Hoffmann Air-Conditioning! From the moment I called, the team was professional, responsive, and truly knowledgeable. Thomas personally made sure everything was handled with great attention to detail. The installation was smooth, efficient, and the quality of the work exceeded my expectations. It’s rare to find a company that is both skilled and genuinely cares about their customers. I highly recommend Thomas Hoffmann Air-Conditioning to anyone looking for honest, reliable, and top-notch service. They’ve definitely earned a loyal customer!
Response from the owner:Thank you, Rick, for your kind words and for recognizing our team's hard work; we're grateful for your support and thrilled to have earned your loyalty!
Amazing service from Thomas Hoffmann! They made space in their schedule to come out the next day to fix our air conditioner. They were on time, honest and fixed the problem on the spot. Thank you!
Response from the owner:Thank you, Ashley! We appreciate your kind words about our team's service – it's great to hear we could help you so quickly.
Fast efficient service. Both of the gentlemen that came to my home were very help and informative not to mention polite. It’s difficult to get service advisers to appear at your home when scheduled most times they’re late or don’t show up at all. Not an issue with this team on time, clear diagnosis, quick repair. I would definitely use Thomas Hoffmann Air Conditioning again. I recommend them highly.
Response from the owner:Thank you, Anna, for your wonderful feedback! We're glad to hear that our team provided you with timely and helpful service, and we appreciate your high recommendation.
Response from the owner:Thank you, Ordont, for your wonderful feedback; we're so glad to hear everything met your expectations!
Your Thermostat Is Set Incorrectly
Before examining furnace components, check the thermostat. It may sound simple, but settings can be accidentally changed.
Ensure it’s set to “Heat” and not just “Fan.”
If the fan is set to “On,” it will blow air continuously, even when the furnace isn’t actively heating. Set it to “Auto” so it only runs when heating.
Quick Fix: Adjust your settings and give the system a few minutes to respond.
The Furnace Hasn’t Warmed Up Yet
Sometimes, the furnace just needs a few minutes to get going.
It might blow cool air when it starts while the heat exchanger warms up.
Quick Fix: Wait 2–5 minutes to see if warm air starts flowing.
Pilot Light or Ignition System Issues
It may have gone out if you have an older furnace with a pilot light. Newer models use electronic ignition systems, which can also fail.
Pilot light out? Try relighting it, following your manufacturer’s instructions.
If ignition fails repeatedly, it could be due to a faulty igniter, flame sensor, or thermocouple.
Call a Pro: A certified technician can safely inspect and repair ignition components.
Dirty or Clogged Air Filter
A clogged air filter restricts airflow, causing the furnace to overheat and shut off the burner as a safety precaution. This can result in the system blowing cold air.
Quick Fix: Replace your furnace filter. A clean filter improves airflow, efficiency, and indoor air quality.
Overheating or Limit Switch Malfunction
Your furnace has a built-in limit switch to prevent overheating. If the furnace gets too hot, the limit switch will shut off the burner, but the blower may continue running, pushing out cold air.
Dirty filters, closed vents, or blocked ducts can cause overheating.
A faulty limit switch can also trigger this issue.
Call a Pro: An HVAC technician can test components, check for airflow issues, and reset or replace the switch.
Leaky Ductwork
Damaged or disconnected ducts can allow warm air to escape into unheated spaces like your attic or crawlspace, making the air from your vents feel cooler.
What to Do: Inspect visible ducts for gaps, disconnected joints, or insulation issues. Sealing or repairing ductwork often requires professional attention for hard-to-reach areas.
Furnace Is the Wrong Size
If your furnace is too large or small for your home, it may not heat efficiently or consistently.
An oversized furnace can short-cycle, turning on and off too quickly to distribute warm air.
An undersized furnace may not be powerful enough to heat the entire home.
Call a Pro: A load calculation by a local HVAC expert can help determine whether your current furnace is sized correctly for your home.
Fuel Supply Issues
Whether your furnace runs on natural gas, propane, or oil, insufficient fuel can prevent it from producing heat.
Check that your fuel supply is turned on.
If you’ve recently had service, ensure the gas valve is turned back on.
Safety Tip: If you smell gas, leave the area immediately and call your gas provider and HVAC company.
When to Call a Local HVAC Pro
If you’ve tried basic troubleshooting and your furnace is still blowing cold air, it’s time to call in the experts. At Thomas Hoffmann Air Conditioning & Heating, we offer fast, reliable furnace repair throughout St. Louis and the surrounding areas. Our technicians are trained to diagnose and fix all makes and models of heating systems.
Whether it’s a worn-out igniter, a thermostat calibration issue, or an airflow problem, we’ll get your heat back up and running—and keep your family comfortable all winter.
Need help now? Contact us today or call us to schedule same-day service.
Stay warm, stay safe, and don’t let your furnace leave you out in the cold!
