We have our home’s water heaters to thank for delivering hot water for domestic tasks, like washing the dishes or taking a shower. But traditional water heaters have a built-in inefficiency: they heat water whether you need it or not. Set the temperature to 120 degrees or so, and the water heater maintains that temperature 24/7, even when the water is not being used.
This problem can be conquered by installing a tankless water heater, but if you’re looking for ways to make your existing tank water heater more efficient, you do have some options. Your best strategy will depend on whether your water heater is fueled by gas, electricity or oil.
If your water heater is gas-fired, it is important that it be serviced. Gas water heaters can develop combustion deposits that make the burner inefficient. Plus, that combustion gas is about 80% water vapor and very corrosive, leading to lots of large rust flakes that can form and land on the gas burner. Just like any fossil fueled appliances, it needs to be cleaned regularly to operate safely and efficiently.
Electric water heaters exhibit wear and tear a bit differently. These heaters rely on electric coils, usually two of them, with each heating one half of the tank. As the coils age, they burn out. The surest sign of this is when you all of a sudden start running out of hot water quickly. Repair is a matter of draining the tank and replacing the coil, a job best left to an experienced plumber or electrician.
One way to save operating costs with an electric water heater is to have a 240 volt timer installed that allows the water to come on only when you need it. In a typical day, you’d set the water heater to come on an hour before you wake up to handle the morning showers, then go off during the day only to come back on in the late afternoon and into the evening to handle chores like washing dishes and even baths. Set correctly, you’d only need to heat water 8 to 10 hours a day, rather than 24.
Oil water heaters need the same sort of maintenance that any oil-fired boiler or furnace might, regular cleaning and adjustment of the burner. But oil water heaters have one very distinct advantage over gas or electric heaters: an extremely high recovery rate. A 30 gallon oil-fired water heater can easily serve a family of 6. You’d need a 40 gallon gas or 50 gallon electric unit to even come close to that.
Regardless of the type of fuel you have, it makes sense to spill out 2-3 gallons of water from the drain valve every 6 months or so to clear any sediment that may have settled in the tank. Sediment can act as an insulator between the heat and the water and make the unit inefficient. To do this, hook up a garden-type hose to the drain valve at the bottom of the unit. Open the valve, and let the water drain into a sink or to the outside. Then close the valve, remove the hose and dry the area up, and double-check that it is fully closed and water is no longer leaking out of the drain.
It’s also a good idea to add a water heater blanket to gas or electric units to reduce loss through the shell of the water heaters. Water heater blankets cost only a few dollars and are easy to install by following the manufacturer’s instructions.
If your water heater is in the eight- to 12-year-old range, you’re due for an upgrade and can choose a higher efficiency model. In the meantime, following the above tips will help you ensure greater efficiency for your existing tank water heater.