Tank Type Hot Water Heaters - shut 'em down
I know that hot water heaters is a redundant phrase, but that's what we like to call them, so I'm sticking with the pack on this.
If you want to save energy on the water you heat, even the hot water you heat, then you'll want to shut down your water heater tank when you leave for vacation or go on a trip for more than a day or so.
Other than an electric dryer, the water heater is the single largest energy consumer when you do laundry. Water is hard to heat, so shut 'em down when you can.
Let's start with electric hot water heaters. They're easy. Find the breaker and flip it to the off position. Electric hot water is expensive, so I'd flip the switch anytime you won't be using it for a day or so.
The drawback of doing so is that they are slow to recover, so turn it back on as soon as you arrive back home.
To turn it back on, just flip the breaker to the on position and wait until the tank heats up again. You can hear the heating elements as they turn on, so once you hear them "go quiet," that's a sign that the water in the tank is ready to use.
For gas fired water heaters it's a bit more difficult, but nothing that can't be overcome. There are two approaches.
Turn the heat selector dial to "vacation" or "warm," and the tank basically goes to sleep, only keeping the water a little warm. The pilot light still remains lighted.
If you'd like to turn off the water heater altogether, then you need to turn the valve control to the off position. This shuts off the gas to the main burner and shuts off gas to the pilot light as well.
To relight the pilot light, you'll have to turn the valve control to the pilot position, push and hold the actuating knob while you light the pilot light. This will require that you take off the flame shield from near the bottom of the heater.
After the pilot light is lighted, you need to continue to hold the actuating knob down until the thermocouple (a long skinny tube that sticks out right next to or into the flame of the pilot light) has a chance to get hot. When it does, it tells the valve that the pilot light is on and gas can be supplied through the main valve. This will take about 30 seconds.
If the pilot light stays on after you release the actuating knob, then you can turn the valve to the on position and the main burner will light. After that, simply adjust the temperature dial to what you normally prefer and replace the flame shields.
If the pilot light goes out after you release the actuating knob, then try it again, but hold it in longer.
The reason that hot water heaters come with a complex valve is in case the pilot light goes out. In such a case, the thermocouple goes cold and this shuts down the valve, thus preventing it from leaking gas from the pilot light or the main burner when the thermostat demands that the water in the tank be reheated.
Done with Hot Water Heaters, back to Ways to Save Energy