How to Keep Your Water Heater from Exploding

Water heater explosions seem like the stuff of news segments and second-hand tales. However, they do happen and they usually happen due to poor maintenance. Here are a few things you should know to prevent your water heater from becoming a ticking time bomb.

What Could Cause an Explosion?

The most common cause of catastrophic water heater explosions involves excess water pressure. As your water heater produces hot water for your everyday usage, pressure builds up inside the water heater tank. Under normal operation, the temperature/pressure (T&P) relief valve activates when pressures exceed 150 pounds per square inch gauge or temperatures exceed 210 degrees Fahrenheit.

Without the relief valve in action, pressures can continue to build up within the tank until the structure catastrophically weakens, resulting in an explosion. The relief valve may fail due to old age, lack of proper maintenance or tampering by an unqualified or untrained person.

Another common cause involves gas leaks near or within the water heater. An errant spark caused by the water heater's ignition device or pilot light could potentially set off an explosion. Internal corrosion can also create an electrical short through the water heater, creating another source of ignition that could result in an explosion. Catastrophic water heater failures can also occur if the unit itself is improperly installed.

Warning Signs to Look Out for

Water heaters rarely fail without warning, so it's a good idea to learn what to look for in a water heater that's on the verge of catastrophic failure:

  • Rumbling, banging or knocking sounds, usually caused by sediment formation within the tank
  • Moisture near the water heater tank, which could suggest a tank leak
  • Rusty water caused by internal rust or corrosion
  • Rusted or leaking relief valve
  • Scalding hot water. This can occur when temperatures exceed 120 degrees Fahrenheit
  • Strong smell of natural gas near the water heater
  • Constant warnings from your carbon monoxide detector

If you see any of the signs from your water heater, you'll want to take action to resolve these issues as soon as possible.

How to Defuse an Explosive Situation

To avoid creating thousands of dollars in damage to your home due to a water heater explosion, it's best to prevent such a situation from happening in the first place. Here are a few tips you can use to insure your water heater operates in the safest manner possible:

  • Have an experienced technician inspect the water heater on a yearly basis. Part of the inspection should include a cursory test of the relief valve.
  • Have the T&P relief valve replaced every 3 years. This will prevent malfunctions caused by old age as well as rust and corrosion.
  • Keep your water heater deposit-free. Calcium, lime and other minerals can build up within the water heater, causing a variety of problems that could create an explosion risk.
  • Steer clear of excess temperatures. The temperature set point on your water heater should not exceed 130 degrees Fahrenheit. Remember, 212 degrees is the boiling point of water and boiling water inside of a water heater is never a good thing.
  • Always monitor the gas lines near your water heater for signs of leaks. If you suspect a gas leak, exit your home immediately and contact the gas company as soon as you are safely outside.

When it comes to water heater repairs and replacement, it's best to just leave the job to the professionals; they have the knowledge, expertise and equipment needed to make repairs safely. To learn more about what's up with your heater and what to do about it, visit online resources like