My Furnace Turns On But No Heat – Why?

image of a homeowner feeling chilly due to furnace heating problems

Your home is a warm retreat when the outside temperature drops in winter. You can turn your furnace on so that the indoor air will heat up. This is a reliable system and is typically in good working condition. However, what happens if it doesn’t work as it should? You may find that your furnace turns on but no heat comes out of the vents. This is a common problem, and many consumers get frustrated over it, especially when the temperatures inside their homes plummet. However, you should keep a level head so you can assess the likely reasons. Some causes require a furnace repair while others are so simple, even a homeowner can tackle it. Keep reading to explore more on this topic.

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Why Is There No Heat Even When My Furnace Is On?

It is a good sign that your furnace still turns on. This means the power supply still works, but there is an issue within the system that is stopping it from working as it should. The problem may be due to a simple oversight that needs a few quick tweaks for the system to return to proper working order. This is typically the case, so there is no need to panic. If it is caused by a more complex problem that you cannot handle on your own, contact a licensed HVAC technician to help you.

Keep reading to know some of the most common causes of why your furnace isn’t producing heat even if it is turned on. These are incorrect thermostat settings, airflow problems, furnace ignition issues, and not enough fuel.

This article talks about how problems can occur in these areas. It also includes basic troubleshooting so you can set the issue straight. As mentioned above, these are simple tasks that all homeowners can do on their own. With luck, your furnace will return to proper working order, and the problem will be resolved. However, don’t try to do more complicated repairs if the furnace doesn’t respond as it should after troubleshooting. Contact a reliable HVAC company for professional assistance. Learn what you can from the issues you encounter, and do what you can to keep these problems from happening again.

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Related Article: Must-Know Furnace Repair Tips For Homeowners

Thermostat Problems

homeowner adjusting thermostat when furnace not working

Furnaces are created to do as they’re instructed. You will get unexpected results if the instructions and your intentions don’t match. The thermostat is the heating system’s control center. Therefore, ensure that you input the correct information in your thermostat. For example, you may want the heater to produce warm air, but you haven’t set the thermostat to do heat production. If this is the case, there is nothing wrong with your thermostat. You only need to input the correct settings to achieve your heating goals. The thermostat may be set to COOL, and you need to change it to HEAT. Someone else in your home may have adjusted the thermostat without your knowledge. Never assume that your thermostat setting is correct, and take the time to check it.

Moreover, check the fan settings. Many homeowners think that a moving fan means it is generating and circulating heat. However, this isn’t always true. If it is set to ON, the fan will run at all times, even when it isn’t going through the heating cycle. It is better to set the fan to AUTO, so it will only operate during the heating cycles. This ensures that the heated air is pushed through the vents. You can also set the thermostat higher by 5 to 10 degrees. You will likely feel a noticeable difference when you do so. Call an HVAC professional if you did these steps, but only cold air is being produced.

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Related Article: How to Tell if Your Furnace is Short-Cycling & What to Do

Problems With Airflow

Air should be able to flow smoothly through the system for the furnace to operate as it should. Any furnace issues can stop the heat from traveling from the source to each room. Your furnace may not be producing heat because something is blocking the airflow. Here are several likely culprits:

You Have Dirty Air Filter

image of a dirty hvac filter

Air filters trap dust, pollen, dirt, pet dander, and other airborne debris. They keep the furnace interior and ductwork from getting dirty, but the gunk gradually accumulates. As time passes, the filter’s surface may become covered in a thick layer of debris that’s stopping the air from freely passing through them. This impacts indoor air quality, airflow, and furnace efficiency.

Check the air filters at least once a month and replace them as needed. Many homeowners can follow the furnace manufacturer’s recommendations for filter replacement frequency. However, various factors will determine the best time to replace your HVAC filters. Some homes require more frequent HVAC air filter replacements, especially homes in dusty areas or with many pets.

Related Article: Top 5 Reasons To Have An Annual Furnace Tune-Up

The Vents Are Closed

The problem may be as simple as some closed vents. Walk around your house to ensure that the louvers are open. If not, adjust them as needed. They may get stuck, so it is best to remove the vent covers for periodic cleaning. Consider replacing any jammed covers. You should also ensure that there isn’t anything blocking the air registers or vents. Someone may have moved furniture, blocking a vent off. Place them back where they were for proper airflow.

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Fallen Debris & Other Obstructions

Items may have fallen down the heater vents. Remove the vent covers and shine a light on them to see inside. If you see any objects you can reach, take them out immediately. Wear a pair of gloves for safety if you are unsure what you will be taking out. You can use a long wire or stick for items that are hard to reach.

Related Article: 3 Reasons Your Furnace Is Rusting

Furnace Ignition & Fuel Problems

gas furnace that isn't working properly

The furnace may have low fuel if it turns on but doesn’t emit heat. A furnace cannot accomplish much without an energy source. If you use gas, check the gas valve and ensure it is open. Contact the gas company to verify that there are no interruptions in your service. If there is, determine when it will be restored.

Check how much fuel is left in the tank if you rely on heating oil or propane. Schedule a delivery service as needed. Prevent this problem from happening again by monitoring your fuel levels and being mindful of your regular fuel usage. You can also set up monitoring devices to help you keep track of fuel levels. You can also sign up for automatic fuel delivery, so the propane or heating oil company handles the monitoring and schedules prompt refills for you.

After you are sure you have fuel, the ignition system may be causing the problem. This component is responsible for starting the fuel combustion. Your furnace cannot generate sufficient heat if the ignition system doesn’t work as it should. Ensure the pilot light is lit if you have an older model. If it isn’t, follow the manual’s instructions on relighting the pilot light. Inspect the ignition switch in the electronic ignition system if you have a newer furnace model. Carefully clean off the dirt on the metal strip, if there is any, before retesting the ignition.

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It can be confusing when you have a furnace that turns on but doesn’t heat your home. Hopefully, this article has helped you understand the problem better so that the next time you face it, you know the best troubleshooting steps to take. Call your local, trusted HVAC technician if the tips mentioned in this article don’t work. Licensed HVAC contractors have the right tools, extensive training, and skills to tackle complex issues. They can correctly and quickly diagnose the underlying cause of the problem and resolve it using the best possible solutions.

Related Article: Why Is My Furnace Leaking on the Floor?

Call R.F. Ohl For All Your HVAC Requirements

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For high-quality heating and cooling services in the Poconos and the Lehigh Valley, Pennsylvania, call R.F. Ohl. All our professionally certified technicians can provide you with superior HVAC services, including mini-split tune-ups, air conditioner repairs, boiler replacements, furnace installations, and more. Our friendly techs have the knowledge, skills, and experience to service your HVAC system promptly and correctly.

R.F. Ohl offers highly competitive HVAC service prices in the area. If you want to have increased energy efficiency and comfort while lowering your energy costs, rely on our maintenance services. We can recommend the best HVAC repair or replacement system that best fits your home and budget. All our work is guaranteed because your satisfaction is always our priority. Call R.F. Ohl and schedule your next service appointment today to receive a free, in-home estimate.

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