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.
I’ve been using “THOMAS Hoffmann Airconditioning and Heating LLC” for years now. We have a 30 +\- year old system that works perfectly for us. Although we’ve not had to use it yet, it is comforting to know they offer a 24 hour on call service. I really appreciate that the technicians don’t try to upsell us on anything. They’re a very professional, knowledgeable, and courteous, local-family owned and operated business. I’ve also found their pricing to be very fair and by”fair” I don’t mean “cheap” but reasonable… especially for the quality of service provided by THOMAS Hoffmann HVAC. I love supporting smaller family owned business and this one is top-notch! Thank you guys!
Response from the owner:Thank you so much for your continued support and kind words, Mari! We truly appreciate your loyalty and are glad to hear about your positive experiences with our services. We look forward to continuing to provide you with top-notch service in the future.
Excellent service from Nick! Friendly was super knowledgeable!
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.
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.
Nick was was great! He provided great service, explained everything, and was patient and kind.I definitely recommend using Hoffman!
Response from the owner:Thank you, Marilyn! We're glad to hear that Nick provided you with excellent service and made your experience enjoyable. We appreciate your recommendation!
The whole team was great, professional and friendly. Scheduling was easy and well organized, they had many options for different price points and financing options. Thank you!
Response from the owner:Thank you for the thoughtful review, Jasmine! We appreciate your support and continued business.
Love that it’s the same technician every time. Let’s me know what he found and any concerns he might have regarding our units. Great customer service.
Response from the owner:Thank you, Theresa! We're glad to hear you appreciate having the same technician and the communication about your units. Your feedback on our customer service means a lot to us!
From the phone to the completion of the job everyone is so polite and informative. I had Giovani as our representative and he was very informative and professional, and knew exactly what the problem was. Thanks so much.
Response from the owner:Thank you for the kind review, Frank! We appreciate you and your business.
Zach did an excellent job! Always courteous and friendly. We would highly recommend calling Thomas Hoffmann HVAC for any heating and cooling needs.
Response from the owner:Thank you, Allan! We're glad to hear that Zach provided excellent service and appreciate your recommendation for Thomas Hoffmann HVAC.
Was able to locate the problem right away and replace a switch and add Freon very nice job by this employee. I will recommend Thomas Hoffman for future references.
Response from the owner:Thank you, William! We're glad to hear that our team was able to quickly address the issue and that you had a positive experience with Thomas. Your recommendation means a lot to us!
I had Nick come out. He was awesome. Very knowledgeable, prompt and helpful. I will definitely recommend Thomas Hoffmann HVAC to others in need of HVAC support.
Response from the owner:Thank you, Jack! We're glad to hear that Nick provided you with excellent service. We appreciate your recommendation and look forward to assisting you and others in the future.
From our initial quote until the new furnace and AC were completed, everything was smooth and efficient. Zachary and Giovanni were excellent on-site, taking time to explain the installation as well as leaving the home clean. Thank you Thomas Hoffmann team
Response from the owner:Thank you! We're glad to hear that the installation process was smooth and efficient. Zachary and Giovanni will be pleased to know their efforts made a positive impact. We appreciate your kind words about the team!
Update 4/6/26: Zach Sperling is such a pleasant and knowledgeable technician that I recommend him highly. Thomas Heating has been a wonderful company to work with in my maintenance plan. If you are looking for a reputable company, look no more.
This company is so responsive that I love them. They respond immediately, and I trust them to tell me what needs to be done. I haven’t been steered wrong yet. They are genuinely nice to work with and honest. I use their maintenance program which I highly recommend.
Response from the owner:Thank you for your kind words, we truly appreciate your trust in us and are glad to hear about your positive experience with our services.
work good but got at least 6 messages from them very annoying
Response from the owner:Thank you for your feedback, Harold. We appreciate your input and understand how too many messages can be frustrating. We'll work on improving that experience for you.
Nick was great! He came right out and was able to solve the problem fairly easily. He communicated well and helped us prevent a future problem as well.
Response from the owner:Thank you for the review, Philip! We are happy to hear you had a pleasant experience working with us.
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.
They have never failed to fix my hvac problems. These folks are top tier.
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!
Giovanni was very professional, helpful, patient and helped me figure out the issue, if it was covered under warranty, and next steps. Great overall experience and much appreciated.
Response from the owner:Thank you, Amy! We're glad to hear that Giovanni provided you with such professional and helpful service. Your appreciation means a lot to us!
Always professional and thorough whenever they service our home. We have used Thomas Hoffmann Air Conditioning & Heating multiple times since we moved into our home and will continue to use them in the future.
Response from the owner:Thank you for the thoughtful review, Joe. We appreciate you and your business!
0 stars if I could. Bought a faulty (not to mention overpriced) surface igniter, called back five minutes later after installing, of course they didn’t stand behind their part. Go to Grainger instead. Same (working) part, half the price.
Response from the owner:Hi there. I am unable to locate your customer profile. Please give our office a call at 314-471-7625 so we can get this figured out for you.
My furnace was not working. A very nice gentleman came out this morning and fixed the problem and now I have much needed heat. He was very professional and courteous. I will definitely be using them again when the need arises.
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!
I will always call Hoffmans for my air and heat needs. They were out to my daughters house that day and fixed it. It was right before the weekend storm with below zero temps the next day. They saved my daughter and grandbabies. I could never thank them more.
Response from the owner:We are so happy to hear that we could help! Thank you for the kind review.
Snow and drifting snow covered intake and out take vents causing the furnace emergency to shut off furnace. Cleaned off the driftibg/ snow off roof and vents furnace works perfect now. Thank you and great job Nick.
Response from the owner:Thanks for the great review, Scott! We appreciate your support.
Came during a storm with emergency call for heat- did a quick and fast job getting furnace running! Whoot!
Response from the owner:Thank you for the great review, Jessica! We appreciate your support.
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!
