Today’s electric tank water heaters are all well insulated to keep the water that we’ve paid to heat stay hot until it’s needed. But with just a little bit of knowledge, there are things we can do as homeowners to keep them operating efficiently long beyond the life of their warranty. Here are things I recommend:
• Raise it up. Electric water heaters do not rust out on the bottom if they are set up on bricks or plastic PVC couplings to allow air to circulate under them. Water vapor comes through concrete and will cause the metal to rust much quicker on a unit that sits directly on the concrete floor.
• Drain and turn back the heat. Draining an electric tank water heater regularly can help flush out accumulations of calcium. But it must be done frequently. Follow the manufacturer’s directions when you do. But draining yearly is not likely often enough. Another strategy to reduce the calcium buildup is to lower the thermostat setting to 120 degrees. Calcium production is based on water pressure and temperature. There is not much a homeowner can easily do to the water pressure that is delivered by the water utility company. But you do have easy control over the temperature of your water heater.
Water at a 140-degree F setting produces more calcium buildup than at 120. And the buildup from 160-degree water is much higher yet. So turn the temperature down. Not only will the reduction in temperature reduce the calcium buildup, a setting of 120 is also recommended for safety to prevent accidental scalding, especially if there are young children in the house. A water softener also prevents calcium buildup in a water heater tank.
• Kick off the blanket. Electric water heaters today have foam insulation all over the unit to include the bottom. Since April 2015, the insulation is thicker to provide a small 5 percent increase in energy efficiency
for a 50-gallon model. So no insulation pad is necessary for the unit to sit on to disconnect it from the cold floor. In fact, some manufacturers do not honor their warranty if an insulation blanket is installed on some of today’s new models as it might cause controls to get too warm for proper operation.
• Don’t spare the rod. Though the metal tank of electric water heaters is lined with glass to keep the tank from corroding, the glass coating is not perfect where the threaded hot/cold water connections, heating elements, relief valve and the bottom drain valve penetrate. This makes the tank vulnerable to corrosion and leaking.
Manufacturers install an anode rod that sacrifices itself to protect the tank. As long as there is material on the rod, bare steel exposed under water will not corrode. The amount of anode material is calculated to last as long as the tank warranty of the unit. So a six-year tank replacement warranty has enough anode rod material to last for six years. After that, your tank is subject to corrosion that will eventually result in a leak and the need for replacement of the unit.
But you can make a tank last many years longer if you replace the anode rod before it is completely used up. Some anode rods are in the $20-$25 range. Want to make your present electric water heater last a lifetime? Replace the anode rod before the warranty period has expired and every five years or so thereafter.
• The hole in the truth in advertising. Do you have an old water heater you think that’s too late to save and are looking for a replacement? The advertising is not always the whole story. Tankless water heater promotions infer they will save a large quantity of electricity compared to a tank style water heater. They imply there is a large amount of electric power consumed by a tank model to keep water hot when no one is home to use the hot water.
At Harrison REMC, we have a meter on a tank version of an electric water heater to monitor the use of electricity in a standby situation. The amount is less than $2 per month. So be careful about allowing that issue to be a deciding factor in wanting to invest in a tankless electric water heater. The conclusion you are led to is, the dollar cost is a unsubstantiated large figure that will be saved when you have a tankless electric water heater because there is no tank to keep hot 24/7. But for those worried about the cost of electric power, an electric tankless water has a 5 times larger electric heater than a tank version. It will increase the peak electric power demand by 5 times compared to a tank model. If a large number of REMC members invest in tankless electric water heaters, that technology will cause higher electric rates.
When following any advice, know your limits before attempting maintenance. First, and foremost, always make sure the power supply is off. A water heater is directly wired and must be shut off at the circuit box. Your electric cooperative’s energy advisor is always a phone call or email away if you have questions about ways to use energy more efficiently and safely.
Bob Geswein is energy advisor at Harrison REMC. The electric cooperative is based in Corydon, Indiana.