Your gas water heater might look benign, but if it's improperly installed or maintained it's a potential ballistic missile that could erupt with enough force to lift your house off its foundation. Every year a few water heaters explode with devastating results. To make sure yours is safe, follow these simple steps:
Remove paper, accumulated dust or other combustibles from the heater enclosure.
Extinguish the pilot light before using flammable liquids or setting off aerosol bug bombs near the unit. Never store combustibles close by.
If the device is in the garage, raise it so the pilot light is 18 in. above the floor. This can help prevent ignition of gasoline vapors that collect near the floor.
Inspect the flue for breaks or gaps that could leak deadly exhaust gas. (This is a good practice to do on other gas appliances.)
Ask your service technician to check the temperature pressure-relief valve, a faucet-like device mounted on the top or side of the heater. Excessively high temperature or pressure causes this valve to open, relieving pressure and preventing a steam explosion.
Consider installing an automatic gas-shutoff valve (below) that stops the flow of gas if the ground moves or if gas flow increases dramatically. The valve, which costs around $300, prevents fires when a gas line breaks due to flood, earthquake or other disaster. Some utility companies will install one and let you pay it off monthly.