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May 21, 2025

Why Isn’t My Furnace Kicking On?

If your furnace doesn’t kick on when your house is cold, it can be the worst feeling! Nights get cold in Missouri and coming home to a freezing house is no fun. There are many reasons that can cause furnace failure! The trick is finding out the source of the problem. Here are a few reasons why your furnace may not be working:

The Most Common Furnace Problem

Jay over at Word of Advice TV goes over the most common furnace problem and how to fix it. (Hint: it’s the flame sensor.) And it’s exactly the reason that regular furnace maintenance is so important. Dust, debris, and carbon build up up over the months. This video is primarily for folks who are hands on or for those who are just interested in the specifics of how things work. The professional HVAC technicians at No Problem Heating & Cooling are happy to do this type of repair and maintenance safely for you.

General Furnace Check List

Your furnace might not be kicking on or it is kicking on and off. The blower runs constantly or is just not heating. Review this check list of common issues you might experience with almost any furnace (electric or gas). These are things most homeowners can do before calling on their HVAC professionals.

Power Problems

First, find out if you have gas or electric furnace. You need electric power for both for the furnace to kick on. Check the circuit box and around the unit to see if any hungry critters have been nibbling on your wires.

Fuses

One of the easiest ways to troubleshoot a furnace malfunction is to check your fuses first. If you have a blown or loose fuse you will not have power at all. You have to remember these machines are so easy but so hard to work on. Buy a new fuse and replace it with the same amp.

Loose Wires

Vibration can cause wires to come loose. At some point, all of the vibrations will rattle wires. When you have your inspection done each year, your HVAC professional will check all of the connections and make sure nothing is loose.

Blower Motor

Most blower motors have an inspection window on the furnace. The flashing green light lets you know everything is okay. If you see a red light, it means your furnace is having problems. When your contractor comes out, they will inspect the control board, motor, and transformer.

Thermostat

Be sure to check your thermostat. Many of the new digital thermostats have fail-safes and different modes that could cause the furnace not to start.

Check the thermostat and make sure it’s set to heat. If it’s 40 degrees outside and you have it set to 38, it won’t kick on. The temperature to heat should be set to higher than the actual temperature in the house.

Also, if the thermostat has been switched to fan please change it to heating. This is a very commonly forgotten step.

Air Filter

One of my favorite furnace issues because it is the cheapest for you is the dirty old air filter. You have to be aware of and maintain your air filter. The changing of an air filter can take less than a minute. If you are into NASCAR, even faster than that. Remember keeping that air filter clean can save hundreds of dollars over the life of the furnace.

Condensation

A condensation pan on the furnace collects excess water and if this gets full, it will cause the furnace to stop turning on. Normally, draining of the pan is not an option although it could work temporarily. We have seen blockages that prevented water from draining. In addition, we have seen a bad condensation removal pump.

Starting Capacitor

Sometimes a starting capacitor is not giving enough power to the system to kick it on. Fortunately, replacing your capacitor is an easy and cheap fix.

Check List for Gas Furnace Repair

Review this check list of common issues you might experience with your gas furnace.

Gas Supply

Check your gas valve and make sure nothing is off. Some homeowners turn down the valve during the summer months or it may have been switched accidentally at some point.

Not Enough Gas

Take the time to check the valve is completely on. Sometimes, a furnace won’t kick on because the valve is half turned.

Gas Valve

You could easily have a failing gas valve in your lines. When debris gets in the valve, it can make it hard for it to open or close. When this happens, it will heat up then the system will short and blow a fuse.

Pilot Light

Check for your pilot light – it should be blue. If you don’t see it, make sure you call an expert.

Electric Furnace Repair

Your electric furnace is going to be much different from the gas furnace check list. The control board is going to be your main source of power. Unless you know what you are doing, we would not recommend messing with it. Call your local HVAC contractor, like No Problem Heating & Cooling, to have it inspected and fixed.

HVAC Maintenance Program

HVAC Pro Tip: Having a maintenance program agreement with an experienced HVAC company can prevent this entire scenario from happening.

Furnace issues often appear when the first chill sets in. While we wish those warm days are going to last forever, we forget just how cold winters can be! Meanwhile, your furnace has been inactive for half a year. As a Club Member, you’re shielded from these surprises. We’ve got you covered, no matter the make or model of your furnace.

Every Club Membership includes two visits per year. We come once in the fall to inspect and maintain your furnace and once in the spring for your air conditioning unit. Learn more and sign up for our Club Membership today.

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Jeanne profile picture
Jeanne
24 September 2026
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Needed furnace to be checked out for the winter. Casey was very nice and explained everything thoroughly. I am very pleased with the service I received.
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Jeff profile picture
Jeff
24 September 2026
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The team at no problem heating and cooling did an excellent job installing my new Mitsubishi mini split from start to finish, l am very happy with the completed project and the way everything was handled and the communication was above and beyond great. I would definitely use them again and refer them to all my friends and family. Thanks again for doing a great job. I will be using them from here on out for all my HVAC needs.
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Patrick Gateway profile picture
Patrick Gateway
21 September 2026
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Fast and efficient, tech was very knowledgeable, fixed the issue less than 4 hours after I called them to make the appointment
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Jada Campbell profile picture
Jada Campbell
18 September 2026
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We had a great experience with No Problem Heating and Cooling! My AC went out, and they were able to get me scheduled quickly after I called. They came out, figured out what was wrong, and explained my options without being pushy about selling me anything. I ended up repairing my current AC but when it’s time to replace it, I’ll definitely be calling No Problem again. They also told me about their air purification systems, and with my allergies, I decided to have one installed. I’m really looking forward to having cleaner air in the house. Thanks for everything! Great service, honest recommendations, and super easy to work with. I definitely recommend No Problem!
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Martha Hogan
14 September 2026
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Casey k. Did a awesome job and we are very pleased 😁
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Laura Ray profile picture
Laura Ray
11 September 2026
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Casey and Donna both worked so hard to get our air conditioner working and back to normal. I cannot tell you how much it meant to my husband and I. When Casey walked into our home, it was almost 90 degrees, and thanks to both of them - less than 12 hours later - it was a perfect temperature. Even while experiencing a heat wave, our air conditioner works perfectly! THANKS TO DONNA for arranging his crazy busy schedule to fit us in as an emergency and THANKS TO CASEY, for his knowledge and expertise on how to fix the problem in less than an hour. I WILL ALWAYS YOUS NPM HEATING & COOLING LLC, and will recommend them to all of our family and friends. I can't tell you how grateful we are. Thanks again. Laura Ray
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Lindsay Burle profile picture
Lindsay Burle
9 September 2026
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Service was fast, professional, and they did a great job!
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Sara Fager
9 September 2026
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Very skilled, professional and on time. Did a great job on a new system. Good communication process and very responsive. I highly recommend.
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