Water Heater Safety
A standard tank-type water heater may look benign, but if improperly installed or maintained it is potentially very dangerous. Every year in the U.S., a few water heaters explode, leak deadly exhaust gas or cause fires with devastating results. Following are several general steps that can be taken to help prevent this from happening to you (for specific installation requirements for your unit, please consult your local building authority):
- All paper, accumulated dust or other combustibles should be removed from the water heater enclosure and never store combustibles close by. [gas water heaters]
- Extinguish the pilot light before using flammable liquids or setting off aerosols near the unit. [gas water heaters]
- If the water heater is in a garage, the unit is required to be elevated so the pilot light is at least 18" above the floor; this can help prevent ignition of gasoline vapors that collect near the floor. [gas water heaters]
- If the unit is installed in a location where it may be subject to vehicle impact (e.g., garage, driveway, etc.), it should be protected by an approved barrier.
- An improperly functioning exhaust flue can leak deadly exhaust gases. The exhaust flue should slope upward, have no breaks or gaps and be free of any obstructions. Additionally, the unit's downdraft diverter must be properly installed at the base of the flue on top of the water heater. [gas water heaters]
- An approved temperature/pressure-relief valve (TPR valve) should be installed on the unit. This faucet-like device is mounted on the top, or near the top on the side of the water heater. Excessive temperature increases tank pressure which can cause a water heater to explode. A properly installed and functioning TPR valve will relieve pressure and prevent a steam explosion.
- An approved metal discharge pipe should be installed on the TPR valve. This pipe should point down and extend to within 6" of the floor.
- If installed inside a home, an approved catch pan should be placed below the unit. This will help prevent damage to the home if the water heater leaks. These pans are commercially available.
- If the water heater is not located within line-of-site of the electrical panel, an approved electrical service disconnect must be provided nearby to prevent accidental electrocution of anyone servicing the unit. [electric water heaters]
- The water heater should be securely strapped to help prevent the unit from falling during an earthquake.