Your water heater may remain unseen, hidden in a utility closet or sitting alone in a basement, but keep in mind that it needs regular maintenance for safety reasons. To make sure yours is safe, get to know its parts and learn some important facts.
Water heater parts
Most residential tanks hold 40 to 60 gallons and have to be able to hold the pressure of a residential water system, which typically runs at 50 to 100 pounds per square inch (psi). Steel tanks are tested to handle 300 psi and normally have a bonded glass liner to keep rust out of the water, as well as insulation surrounding the tank. Other water heater parts include:
- A dip tube to let cold water into the tank
- A pipe to let hot water out of the tank
- A thermostat to control the temperature of the water inside the tank
- Heating elements similar to those inside an electric oven
- A drain valve that allows you to drain the tank to replace the elements, or to move the tank
- A temperature or pressure relief valve that keeps the tank from exploding
- A sacrificial anode rod to help keep the steel tank from corroding
Temperature or pressure relief valve
A temperature or pressure relief valve helps prevent a tank from exploding if temperature or pressure exceeds safe limits. Unfortunately, residential valves are somewhat prone to failure. As part of your annual water heater care, test this valve by:
- Pulling up on the handle to make sure water flows freely out, and stops when you let go of the handle. If it does nothing or runs or drips, then the valve should be replaced.
- Flushing the hot water heater through the drain valve at least once a year to remove sediment buildup. You should have a drain line, usually to within about 6 inches of the floor, or plumbed outside. This is to prevent you from being scalded if the valve should open while you’re standing next to it.
On residential tanks, the settings are normally warm, hot, very hot or something similar. There is so much variation on what these settings mean, but the right temperature is at least 130 degrees at the tap, which you can test with a meat or candy thermometer.
It is important to keep the temperature close to 130 degrees. Even though you can be scalded at 130 degrees if you spend long enough under the water, you’ll probably draw back before that happens. If the temperature is below 120 degrees, Legionella bacteria can grow and you could catch Legionnaire’s disease by inhaling the mist when you take a shower. Temperatures above 130 degrees increase your scalding risk, encourage sediment buildup and waste energy.
When leaving for vacation, set the hot water heater temperature at its lowest setting. This will save money and reduce the risk of any problems while you are away. Also, if your faucets are sputtering, spitting and spewing, it could be a sign that your water heater is overheating.
A poor draft can cause fumes and carbon monoxide to come back into the room instead of going outside. To maintain good ventilation make sure that:
- The vent is the same diameter as the tank's draft diverter
- The vent goes straight up and out, without any dips
- Where it passes through walls or roofs, it is double-walled. Single-walled vent sections should be screwed with 3 screws per section, especially in earthquake zones
Strapping your water heater is a good idea, even if you live outside an earthquake zone. If your water heater were to fall over for any reason, it could sever the gas line and cause an explosion.
Additional water heater safety tips
Keep safe by following these water heater recommendations:
- 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.
- If the device is in the garage, raise it so the pilot light is 18 inches above the floor. This helps prevent ignition of gasoline vapors that collect near the floor.
- Consider installing an automatic gas-shutoff valve which 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.
- You may also want to insulate the first 6 feet of the hot water pipe and the first 3 feet of the cold water pipe that extends from your hot water tank. Insulating the hot water pipe reduces heat loss and insulating the cold water pipe reduces “sweating” in the summer. You can find pipe wrap insulation for this purpose in most hardware stores.
- Do not use pipe wrap or any other insulation within 6 inches of the draft hood or flue exhaust vent at the top of the natural gas water heater.