What Causes a Hot Water Tank to Explode

When it comes to having to do maintenance on ones water heater, it is a fairly low maintenance appliance. However, one crucial element of it should be inspected regularly to prevent a needed water heater repair.  We want to pass along this safety information about ones Rio Rancho water heater today.

Excessive temperature when combined with tank corrosion within the storage tank can cause an explosion. When the water temperature is below 212 degrees Fahrenheit, one will be safe from an explosion, though there is a danger of scalding at that temperature. But, if the water temperature is above 212 degrees, water turns into steam, which will then expand to 1,700 times the space it occupies as water. This is when an explosion can occur.

Warning Signs of a Water Heater Explosion
The leading sign is if one goes to get hot water from a faucet and only steam comes out. Immediately turn off power if one has an electric water heater. If one owns a gas hot water heater, shut off the gas valve going to the water heater. Then, get in touch with us to come assess the situation.

Minimizing Potential Water Heater Dangers
The most important maintenance task with a water heater is to test the pressure relief valve, also called the T&P valve, on a regular basis. This valve helps regulate the pressure buildup inside the water storage tank to prevent a dangerous rise in temperature and over pressure.

Be aware, the water discharge from a T&P valve can be very hot. If you do not feel comfortable testing the valve let us know. Also, doing any type of repairs to the valve should be done by a professional plumbing repair company.

How to Test the T&P Valve

Remove anything from around the area around the overflow pipe and floor drain.
Lift the test handle for approximately 5 seconds or until the water runs clear.
Release the handle.
If the T&P valve continues to run with water, lift the handle up and down quickly to get it to reseat itself. One may have to do so a few times. IF it has not been tested for a while, it might be difficult to raise it at first. Don’t use too much force, but may need to use a little.
If the T&P valve remains leaking, it should be replaced.

Other things to look for are corrosion on the stem of the valve. If there is any water leaking from the valve stem or out of the drain valve.

Water Heater Maintenance Infographic


Katy Texas Water Heater Maintenance

Related T&P Valve Testing Videos

Mythbusters did a test of the potential dangers of hot water heater explosions here:
Water Heater T&P Valve Repair Katy TX

What the Experts Say

  • The discharge from a T&P valve can be very hot. It is very important that all T&P valves be installed properly with a discharge line piped downward to an adequate drain to avoid property damage and to minimize possible human contact.
    Read more…

Watts Water Technologies

If the temperature in your heater remains high after you turn down the thermostat, the thermostat may be faulty. Consult a professional for repair. Read more…

Home Guides

Pressure relief valves sometime develop a drip when opened for the first time in years. Try opening and closing it a few times to see if it will seat itself. If you have a large leak or the drip doesn’t stop on its own in a day or two, the valve will need to be replaced.  Read more…

Today's Homeowner

Check out some of our other water heater tips in our blog