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Why Won’t My Furnace Light?

HVAC technician inspecting malfunctioning furnace

A furnace not lighting can be a frustrating and potentially dangerous problem. In many cases, troubleshooting and resolving these issues requires professional expertise. Knowing what might cause a furnace not to light can help you determine the best action to address the problem.

Below are some common reasons why a furnace may fail to light.

Dirty Air Filter

Poor airflow is one of the factors that will prevent a furnace from starting. When the filter becomes overly dirty or clogged, it limits how much air can circulate through the system, making it difficult for the furnace to run correctly. A dirty filter also restricts airflow across the heat exchanger, putting strain on the motor and blower components. This added strain can make it difficult for the furnace to even turn on in some cases. That's why regularly changing or cleaning your air filter is essential for maintaining your furnace.

Dirty Gas Burners

Dirty gas burners in a furnace can severely impede the efficient operation of the unit and can even cause a complete failure to start. This is because if the opening is clogged with dirt and debris, it will prohibit the flow of necessary gases for combustion, resulting in a non-functioning system. To keep your furnace running safely and properly, it's important to regularly and thoroughly inspect all burners for any obstructions or build-up. This is especially true if you have an older furnace that may be more prone to wear or poor maintenance.

Broken Flame Sensor

The flame sensor in a furnace is an essential part of the system, as it monitors the flame being produced. If no flame is present, it will shut off the furnace to avoid dangerous situations such as gas leakage. Therefore, when the flame sensor becomes broken or damaged, it will not be able to accurately detect whether a flame is active and working within the furnace, leading to a non-functioning furnace. It is imperative to ensure that all parts in your furnace are in good condition to function correctly and safely.

Broken Thermostat

A broken thermostat can prevent your furnace from starting up for many reasons. If the thermostat is not working properly, it will not be able to detect the temperature in your home accurately. This causes the furnace to think it does not need to turn on, leading to it failing to start up. Additionally, if you have a digital thermostat, it may be the case that the batteries need replacing. In any case, ensuring that your thermostat is in good condition and functioning properly is crucial to keep your furnace running correctly.

Will Your Furnace Still Not Light?

If you've arrived at this course of action, you should know that having a professional look at your furnace is in your best interest. When you contact Korrect Plumbing, Heating & Air Conditioning, Inc. our technicians can help to resolve your problem quickly and safely so that your home or business will be warm again in no time.

Let our team diagnose what caused the original issue that led to your furnace not starting. Reach out online or by phone today to schedule an appointment. (937) 837-2333

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