Oct 17

What To Do When Your Furnace Blower Keeps Running But No Heat

image of a homeowner feeling chilly due to furnace turning on but no heat

You may or may not need to call a professional if your furnace turns on but doesn’t heat your home. It depends on the situation, as some furnace problems are easily resolved, while others need specialized tools and technical knowledge. The ideal case is that you address the simple causes first before the complex ones. Conduct some furnace troubleshooting first if you have a situation where your furnace blower keeps running but no heat. Read on to learn these HVAC troubleshooting steps before contacting your local, trusted HVAC professional.

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How To Troubleshoot A Furnace That Is Running But Not Producing Heat

Here are some of the steps you can take when your furnace isn’t generating sufficient heat:

Check the Furnace Condensate Line

The high-efficiency and newer furnaces produce water during their operation. This water is eliminated via the drain line. The water can back up and trip your overflow kill if you have a blocked drain line. This will cause your furnace to turn off. A puddle around your furnace is typically a good indicator that the condensate line is blocked, so you should book professional furnace cleaning.

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Hit the Heating System Reset Button

Many furnaces have a red reset button. Hit this button to try to get your furnace working back again. However, call a professional HVAC technician if you often need to keep hitting the reset button to ensure your furnace stays on. They will assess and diagnose the underlying reason behind this issue.


Check Furnace Thermostat Settings

Incorrect thermostat settings can be the cause behind no heat coming out of the vents, even with the furnace blower turned on. Check the thermostat to ensure the setting is in HEAT instead of COOL. It is a common mistake that happens. The fan runs continuously when it is switched on. This can make it seem like the furnace is on even when the blower is the only component on. As a result, heat cannot be distributed throughout the house as there is no heating cycle. Check the following to help you:

  • Proper Fan Settings: The fan should be set to AUTO so that the blower motor will only run during the heating cycle. A fan that is ON will push the cold air from the blower and use more energy.
  • Turn Up the Thermostat: Set the thermostat temperature several degrees higher than the room temperature if the furnace doesn’t produce heat. This triggers a heating cycle, forcing your furnace to kick on.
  • Call a Professional: Contact a professional HVAC contractor if your furnace still doesn’t generate heat even after doing all these steps.

Look Out For HVAC Airflow Problems

image of a dirty furnace filter and homeowner replacing it

Airflow problems with the furnace and ductwork can limit how much hot air is released throughout the house. These problems with the airflow can be caused by dirty air filters, restricting the airflow and limiting the amount of heat streaming out the vents. Below are ways you can deal with problems with the airflow:

  • HVAC Air Filter: Conduct regular air filter checks. Replace it if it is clogged with pollutants. It is recommended that you do checks every month and replace them as needed.
  • Louvers: Check all the vents to make sure all louvers are open. Take the vent cover out and clean it if you find the louvers are closed. Have a certified HVAC technician replace the cover if you have jammed louvers.
  • HVAC Vents and Registers: Vents that are obstructed or closed can seem like your furnace isn’t producing hot air sufficiently as the heat cannot reach some of the areas. Make sure that the vents and registers around your house are uncovered. Large items like furniture and indoor plants usually obstruct the vents and registers. Low airflow in a given vent means you need to peek inside to ensure that no items fell in and are blocking it. Remove these clogs using your hand or a long, thin wire.
  • Duct System: Inspect the ductwork as it may be leaky. If this is the case, the heated air can escape so there will be weaker and cooler airflow coming out your vents. The furnace will have to work harder, and you will have reduced energy efficiency. Your furnace will also have a shortened service life. Therefore, have an HVAC professional seal all leaks and gaps to keep your furnace efficient.
  • Book Professional Furnace Maintenance Regularly: Prevent airflow problems from happening in the first place by scheduling regular professional HVAC cleaning and maintenance.
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Look Out for Fuel & Ignition Issues

You may have an ignition system or fuel supply issue if your furnace doesn’t produce heat after turning it on. You can check if you have fuel issues through the following steps:

  1. Look at the gas supply line to make sure the gas valve is open.
  2. Make sure that your tank has enough fuel if you use oil or liquid propane. Book a fuel delivery if you need a refill.
  3. Call your utility supplier if you use natural gas to verify that you are receiving uninterrupted service.

Furnace Ignition Malfunction – Troubleshooting Tips

gas furnace flame

An ignition system that isn’t working means the gas will not burn to generate heat. Here are steps you can do if your furnace has ignition malfunction issues:

  • Check the Pilot Light: See if the pilot light was snuffed out if you own an older furnace. It needs to be relit if this is the case. Check the owner’s manual to know how to relight the pilot light properly. Make sure to follow the manufacturer’s directions correctly.
  • Electric Furnace: If you have an electronic ignition system and it is failing to generate heat, the metal strip in the igniter switch may be dirty. Check the metal strip’s condition. Gently clean it if it is dirty. Remember that this component is highly fragile, so handle it with extreme care. The best option is to have a professional clean it.
  • Don’t Light Your Furnace Manually: It is unsafe to light your furnace manually, so do not try to do it. Take a look at the blower if the furnace motor is running, but no heat is being generated. The belt may be misaligned or broken.
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Different causes may result in your furnace not generating heat. These issues need varying solutions. If the problem persists even after trying these troubleshooting steps, call an HVAC professional to assess, diagnose, and repair the problem before it is too late to do anything about it.

Call Skylands Energy Service For All Of Your HVAC Requirements

image of skylands energy service logoSkylands Energy Service offers high-quality heating and cooling services in central New Jersey. We have professionally certified HVAC technicians to perform HVAC maintenance, replacements, installations, and repairs. All our knowledgeable and experienced techs can service your HVAC system correctly at all times.

If you are looking for the most competitive HVAC service prices in the area, don’t hesitate to call us. Our tune-up services can help you increase your home’s comfort and energy efficiency while lowering your heating and cooling bills. We can provide you with the best solutions if you need to replace or repair your HVAC system while staying within your budget. All of our work is guaranteed because your satisfaction is important to us. Schedule your next service appointment with Skylands Energy Service today and receive a free, in-home estimate.

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