Water shutoff valve: This is where you’ll shut off the flow of water into your hot water heater in case of an emergency. You’ll find it on top of your water heater, right on the incoming cold water pipe. If it’s a dial, you can turn it clockwise (righty-tighty) to turn off the flow of water. If it’s a lever, then turn it until it’s perpendicular to the pipe to stop the flow.
Gas shutoff valve: Like the water shutoff valve, the gas shutoff valve is critical in an emergency. It’s usually located near the bottom of the water heater, and it’s a lever. Turn it perpendicular to the pipe to shut off the gas flow.
Drain valve: Your water heater’s drain valve is near the bottom of your tank, and it works just like the drain at the bottom of an ice cooler, only with a faucet. Turn it counterclockwise (lefty-loosey) to allow water to drain from your water heater. Use caution anytime you do this, because unlike the melted ice you’re draining out of a cooler, the water coming out of your water heater will be hot.
Pressure relief valve: This valve is designed to automatically release water or air pressure in your water heater’s tank in case the pressure builds up to dangerous levels. You shouldn’t have to mess with this valve often, but it’s still good to know where it is. It’s usually located about two-thirds of the way up your water heater, and it should have a pipe attached to it that ends a few inches above the floor. This is so that any hot water or steam escaping will be directed at the floor, not your face.
Thermostat: As the name suggests, your hot water heater thermostat controls the temperature of the water in your water heater. It’s usually located near the bottom of the water heater, and it either has a knob or a screw slot so you can adjust it to your desired temperature. The US Department of Energy recommends that you set your water heater’s thermostat at 120° F to save on energy and prevent scalding. Set the temperature lower if you’ll be away from home for an extended period of time to save energy.
Heating element: Your hot water heater’s heating element is located inside the unit, but depending on the type of water heater, you may also be able to access it from the outside. If you have a gas water heater, it’s basically like a stove burner at the bottom. For an electric water heater, it’s usually two horizontal electric rods that heat the water.
Anode rod: This is a metal rod that attaches to the top of your water heater tank and hangs down into the water. Its job is to attract any corrosive minerals that might be present in your water so that they corrode the rod, not the inside of the tank. Anode rods deteriorate and need to be replaced periodically.