Why Does My Gas Furnace Give Me A Headache When It’s On?


Headaches are one of the most common pains or discomforts people have. They can also detract or even stop you from going about with daily activities.

What if you notice that the headaches almost always start when your central gas furnace is on? It’s not uncommon to ask, “why does my gas furnace give me a headache when it’s running?”

So, how can you tell if the heating system causes your head pain? Let’s find out if your suspicion about furnaces is correct.

DP why does my gas furnace give me a headache

Is Your Central Gas Furnace Giving You Headaches?

The central heating gas furnace CAN give you headaches if: 

  1. Furnace filters are dirty or in need of replacement. Clogged filters are filled with dust, dirt particles, pet dander, and other indoor air pollutants. If left unchecked, these toxins can circulate into your breathing air and trigger allergies. Headache is one of the most common symptoms of mild and severe allergies.
  2. Your ductwork needs cleaning. Same with filters, neglected ducts can accumulate dust and a variety of dirt in them. When the heated air passes through the ductwork, allergy-causing particles can get mixed in with the air the HVAC system produces. Additionally, the burnt dust smell can precede migraines. 
  3. Poor ventilation. Migraines can be triggered by poor indoor air quality due to inadequate ventilation. Your home could be trapping indoor air toxins from household chemicals that you need to let out.
  4. Extremely low indoor air humidity. Misuse or overuse of the furnace will sap out all the moisture from the air causing the mucus membrane to get inflamed or irritated, manifesting as headaches. Heated air can also cause chemicals to evaporate causing head discomfort after prolonged exposure.
  5. Carbon monoxide poisoning. Tension-type headaches can be caused by carbon monoxide exposure. But prolonged exposure to carbon monoxide can lead to vertigo, tachycardia, heart attack, and even death.

Symptoms That Your Gas Furnace is Causing Your Headaches

The furnace is a convenient source of warmth and comfort indoors and make those long cold months bearable, if not enjoyable to stay at home.

But imagine if that very home appliance from where you received your cozy and healthy indoor living is the same device that is giving you intense headaches.

Needless to say, you would never volunteer to just stop using the central gas furnace so you can get a rest from the head pains. That’s like being between a rock and a hard place!

The great news is you don’t have to toss your furnace aside to stop your headaches from its source.

But before we give you home HVAC tips and information that can help you prevent getting a headache as soon as you turn on your furnace, we should first answer the question, “How can my central gas furnace give me headaches?”

You will be surprised to know that many factors are involved in the truth.

Clogged Furnace Filters

This may be the last place you think to look but your furnace filters could be the culprit for your headache.

If no one has told you already, the principal role of the furnace filters is to protect the furnace itself from foreign objects that may invade its inner workings, damage its parts, and ruin the efficiency of the heating process.

But a good side effect is that through the furnace filters, small unwanted particles that hang around in the air in your room or in the entire home are trapped and prevented to be recirculated. These unwanted particles include dust, pollen, dirt, debris, animal hair, small insects, etcetera. 

Some people may tend to overlook the importance of furnace filters, or simply ignore the need to clean or replace them. However, if the filters accumulated enough harmful particles, it can result to a dirt or dust buildup. These particles the furnace filters worked so hard to filtrate are notorious for causing mild to severe allergies. 

If you’ve been sick with an allergy, you know it gives you nasty symptoms such as itchy and watery eyes, nasal blockage, coughing, difficulty in breathing–and the mother of all symptoms–a throbbing headache.

The solution is simple: regularly clean your filters if they are the washable type, or replace them with fresh ones. You should immediately feel the difference as your furnace’s performance improves, you use less energy, and your headache is gone.

Dirty Ductwork

If most people forget to clean and replace their filters, even more people don’t think of their ductwork to have a direct impact on their head pain.

But in reality, ducts that are left unchecked are susceptible to dust and dirt buildup, too. They could even have become breeding grounds for molds.

This is especially true for a furnace that has not been used for months. If you suddenly turn it on without checking if they are clean or are housing indoor pollutants, you could be initiating the spread of allergens in your home. As we know, allergies cause headaches. Not good.

Some people also develop migraines after smelling burnt dust. Others may argue that it could be just phantom smells or olfactory hallucinations before a migraine occurs, but we don’t want to take that risk, do we?

Before winter comes, clean your ducts or have a professional perform the service for you. This will ensure that you keep those headaches at bay.

Lack of Adequate Ventilation

Typical homes have an abundance of chemicals in common household items such as cleaners, detergents, shampoos, pet powders, metal and wood polish, auto supplies, and many others. While they are not inherently poisonous, they still have a strong chemical smell that can induce headaches.

If your home was made airtight so your furnace can heat up your home quickly, you may not have consider having the right amount of ventilation in your home. Proper airflow is needed so indoor air pollutants that are impacting the quality of air inside your home have a way to escape.

You can use a fresh air ventilation system together with your furnace so you can be sure that you are expelling these toxic chemicals from your breathing space.

Exceedingly Dry Air

Cold weather is typically dry but when the air is heated up by a furnace, it can make the indoor environment even drier. Dehydration headaches feel like our nasal passages were parched because of air dryness, which can trigger painful sinus headaches.

The mucus membrane or the lining of our nose, are supposed to be always moist. If the central furnace system is used extensively, this lining could lose all its moisture and become irritated or inflamed. The inflammation can cause pressure in our face and head which we interpret as a pounding headache.  

Hot dry air can also cause “offgassing,” or the evaporation of chemical particles in industrially-made household items which can cause migraines if inhaled. 

Carbon Monoxide Poisoning

This is the last, and definitely the worst way your furnace can give you headaches. Carbon monoxide poisoning in its mildest form starts with head pain, dizziness, fatigue, stomach and chest pain. In the worst cases, CO poisoning can lead to fatality. 

Carbon monoxide is produced whenever something burns. So all machines that function through combustion or burning of fossil fuel are expected to emit at least a tiny amount of carbon monoxide. These include the central gas furnace systems, along with a gas clothes dryer, gas stove, water heater, and grills.

To prevent your furnace from producing excessive amounts of carbon monoxide, regularly subject your central gas furnace system to checkup and quality service by a professional to know if the heat exchanger has cracked. It also wouldn’t hurt to install carbon monoxide detectors around your home.

Leave a Comment