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3 Real‑Life Water Heater Disasters and the Mistakes that Caused Them

Your water heater is out of sight and that usually means it’s out of mind. But neglecting it can lead to some serious disasters.

Here’s the proof. Ripped out of news headlines, we found 3 types of disasters caused by water heaters. We’ll start with the most common...

1) Home-size floods

Usually when tank water heaters die, they go out with a flood. The tank rusts through and 60+ gallons of water floods your home, like this water heater at a Montessori charter school in California.

Besides replacing the water heater, you’ll likely also have to replace water-damaged drywall and flooring, which can be expensive.

Most likely cause: Completely corroded anode rod. This rod’s purpose is to rust so that your tank doesn't. However, it eventually completely rusts away. Once gone, your tank can start rusting until it eventually bursts.


New anode rod (top) with old anode rod (bottom) via waterheaterrescue.com

How to prevent this: Change the anode rod when it’s almost deteriorated. Generally, an anode rod should last as long as your water heater’s manufacturer’s warranty. So if you have one with a 6-year warranty, replace it in the 5th year. However, if you have a water softener, you’ll need to change the rod much more often, usually every 1-2 years.

If your tank does leak, to prevent damage we also recommend you:

  • Install a drain pan under the water heater to collect the water and keep it from damaging your home.
  • Install a water sensor shutoff valve. These sense when water is leaking from the tank and automatically shut off water to the water heater.

Note: Some tanks don’t have sacrificial anode rods. Make sure yours has one before trying to replace it.

2) Carbon monoxide poisoning

Many water heaters in Minneapolis-St. Paul use gas to heat the water. If there’s a problem with the water heater, carbon monoxide (CO) can leak into your home and poison your family.

According to the Centers for Disease Control (CDC), “Each year, more than 400 Americans die from unintentional CO poisoning not linked to fires, more than 20,000 visit the emergency room, and more than 4,000 are hospitalized.”

And many cases of CO poisoning are from malfunctioning water heaters, such as:

Most likely cause: A venting problem. Combustion (the act of burning fuel like natural gas) creates carbon monoxide. Normally, this poisonous gas is safely vented out of your home. But a problem with the vent can cause CO to back up into your home instead.

How to prevent this: There are several things you should do:

  1. Every home with a gas appliance should have a CO detector.
  2. Make sure there are no obstructions in the vent (like a bird’s nest).
  3. Hire a licensed plumber to check out your water heater annually to make sure it’s venting correctly.

3) Water heater explosions

Water heaters explode if not maintained. It’s not just a funny Allstate commercial. There are recorded cases of it happening in Australia, Arizona and Tennessee. And MythBusters confirmed it can happen, too.

A water heater explosion creates quite the wreckage.


A garage and roof destroyed by a failed water that turned into a bomb. Photo source.

Most likely cause: Failed temperature and pressure (T&P) valve. When water is heated, it expands, creating pressure. This is why boiling water will push the lid off of a pot.

Enough pressure built up inside of your tank can cause it to burst. However, a water heater tank has several safeties built in to keep this from happening. For example, the thermostat doesn’t let the temperature go above a certain point and the T&P valve lets water out of the tank if the pressure gets too high.

But these things can fail, especially when not regularly maintained.

How to prevent this: “Exercise” your T&P valve every six months. This just means opening it for a bit and making sure it turns off.

Prevent water heater disasters with regular tune-ups

Regular water heater maintenance helps prevent problems like the ones above (and more).

  • A water heater tune-up should include flushing the water heater tank (recommended maintenance by your manufacturer) as well as checking:
  • The condition of the tank and anode rod
  • Whether the water heater is leaking carbon monoxide or other dangerous gases
  • How your T&P valve is functioning

Need a plumbing tune-up? Schedule it online or learn more about our plumbing maintenance program.

Minneapolis Saint Paul Plumbing, Heating and Air has been serving the Twin Cities since 1918.