How your gas furnace can poison you (and how to prevent it)

When people think of “dangerous furnace problems,” they usually think “gas leak” because they imagine the action movie-esque explosion that a gas leak can cause.

But you need to be aware of a sneakier problem: carbon monoxide (CO) leaks and poisoning.

In some ways, a CO leak is more dangerous than a gas leak because you can’t see, taste or smell carbon monoxide. Also, you can mistake having CO poisoning with having the flu because they both cause similar symptoms (more on that later).

So, for your benefit, we want to explain:

  • What carbon monoxide is
  • How carbon monoxide can leak from your furnace
  • How to prevent carbon monoxide-related furnace problems

What is carbon monoxide and why is it dangerous?

According to the Centers for Disease Control and Prevention (CDC), carbon monoxide (CO) is an odorless, colorless gas that can kill you. It’s found in fumes produced any time you burn fuel, like in your furnace.

Because it’s scentless and invisible, CO is often called “The Silent Killer.”

But how exactly does it kill?

Well, CO is toxic because it reduces your blood’s ability to carry oxygen because red blood cells pick up CO faster than it can pick up oxygen. If you’re exposed to CO for too long, you’ll die from asphyxiation (lack of oxygen).

To think of it another way, imagine your red blood cells are like taxi cabs that shuttle oxygen from one place to another in your body. When you inhale CO, it’s getting into the cabs (blood cells) before the oxygen can, leaving you oxygen deprived.

That’s why being exposed to a small amount of CO results in these flu-like symptoms:

  • Headache
  • Dizziness
  • Weakness
  • Upset stomach
  • Vomiting
  • Chest pain
  • Confusion

But how can CO escape from a furnace? Let’s talk about that.

How carbon monoxide leaks from a furnace

As your furnace runs, it burns fuel and produces CO. Normally, that CO is safely vented out of your home through a flue pipe. That is, unless any of these 2 things happens:

1) Your furnace’s heat exchanger cracks
When your furnace turns on, it ignites burners that heat the heat exchanger, which then heats your air. Inside the heat exchanger, combustion gases usually exit out the flue pipe. But if the heat exchanger cracks, CO will seep out and get into your home’s air ducts. Essentially your furnace is now delivering CO to each room in your home.

Heat exchangers eventually crack because they’re constantly expanding and contracting due to heating up and cooling down day after day.

2) Something blocks the flue pipe or the flue pipe is faulty
Flue pipes can get blocked by a bird’s nest, causing the CO to back up into your home. Or the flue pipe itself may leak CO.

How to keep your furnace from poisoning you

Do these 4 things:

  • Change the furnace filter when it’s dirty. A dirty filter reduces airflow over the heat exchanger, causing it to overheat, increasing the chances the heat exchanger will crack.
  • Install a CO alarm near your furnace. This alarm will go off when it detects dangerous amounts of CO around your furnace, allowing your family time to escape to safety.
  • Get your furnace professionally maintained once a year. If you call a furnace technician for a tune-up, they’ll check the heat exchanger and the flue pipe, making sure both are in working order.
  • Replace your furnace when it’s 15-20 years old. The older a furnace gets, the more likely you’re going to have problems, like a cracked heat exchanger.

Has your furnace had maintenance yet?

If not, we highly recommend you getting it sooner than later. Not only will furnace maintenance keep you safer, but it’ll help lower your electrical bills.

Contact Santa Fe for professional furnace maintenance.

Santa Fe Air Conditioning and Heating serves the Kansas City area.