The good news is that it’s rare for a water heater to explode. So it’s very unlikely that you’d face this situation in your home. Plus, if you have a tankless water heater, there’s no chance it will explode. And tankless water heaters are becoming more prevalent in homes.
Having said that, every once in a while, a water heater with a tank will blow up. Therefore, it’s important to know the signs of a water heater that’s in danger of exploding. That way, you can take action ahead of time.
What Causes a Water Heater Explosion?
The tank of a water heater is usually made of steel, and it’s sealed up tightly. And, when a water heater’s internal temperature climbs too high, it can create a great deal of pressure inside the tank. If there’s no relief for that pressure, the entire machine could eventually explode.
Another way to think about it is to remember a lesson from middle school science: Most materials expand when they’re heated and contract when they’re cooled. Therefore, hot water will expand a steel water tank — perhaps to the breaking point.
Moreover, when a water heater explodes, it can do extreme damage to a home. It can also cause serious injuries and even fatalities. After all, such an explosion sends hot water and sharp shards of metal flying through the air.
Two Crucial Safety Devices
Fortunately, water heaters come with safeguards. They can prevent an excess of internal heat and pressure.
Thermostat
One form of protection from a water heater explosion is a thermostat. The thermostat keeps the water inside the tank at a steady temperature. (Most electric water heaters have two thermostats, by the way.)
If a thermostat senses that the tank’s water is too cold — if it’s fallen below, say, 80 degrees Fahrenheit — it will trigger the gas burner to ignite. Thus, the water will warm up.
Alternatively, when the thermostat detects that the water is too hot, it will tell the ignition to turn off. That will keep the liquid from getting any warmer.
Note that, if a thermostat stops working, it probably doesn’t mean imminent danger. Most likely, your water would just get too cold, and you’d have to ask a repair technician to come to your home.
However, there are times when a thermostat stops working and the gas burner remains on. Under those circumstances, the water could get increasingly hot. And, due to that heat, the pressure inside the unit could keep building and building.
Temperature and Pressure Relief Valve (T&P Valve)
Even if the pressure inside your water heater keeps increasing, though, it doesn’t mean an explosion will definitely happen. That’s due to the second major safety mechanism: the temperature and pressure relief valve, also known as the T&P valve.
This device keeps people safe in two ways. First, if the water inside your water heater’s tank ever gets too hot, the T&P valve will open and let colder water in. Second, this apparatus can open up and release pressure from the tank.
For added safety, the T&P valve can work without electricity. In fact, you could even activate it by hand if you needed to.
Potential Signs of an Impending Water Heater Explosion
For a water heater to explode, then, the thermostat and the T&P valve would both have to be malfunctioning. For that reason, an explosion is not likely. Yet it’s still possible.
After all, as with any other machine, a water heater degrades with age. And, without regular maintenance as well as replacements for parts that no longer work, the deterioration will happen faster.
Here are several signs that a water heater explosion — however remote the odds — might occur in your home:
- The T&P valve is open most or all of the time. (It’s supposed to close once the pressure inside the water heater decreases.)
- You notice a rotten egg smell near this machine. It could indicate that sulfur, which is combustible, is leaking out of it.
- Gurgles, pops, bangs, hisses, whistles, or other noises are emanating from the water heater. These sounds could mean that sediment layers have formed inside the tank, and that could lead to additional pressure.
- You see discolored water in your sinks, tubs, and toilets. Brownish water can also be a sign of sediment buildup in your water heater tank.
- Water heater leaks suggest internal damage of all kinds.
- Finally, water temperatures that often fluctuate are a major signal that something’s wrong with a water heater.
Of course, whenever you experience any problem with your water heater, it’s best to have a professional look at it right away. Small issues that aren’t addressed often spiral into more serious problems — problems that are costlier to repair.
But, with experts like the Benjamin Franklin Plumbing team taking care of your water heater, your home will be safer and your water will be cleaner and healthier.