COPYRIGHT 2018 JAMES DULLEY ( www.dulley.com/sea/ ) - April 2018 - (graphics ref. No. 319u at www.dulley.com/sea/column/2018-apr.htm 

"Methods to reduce operating cost for old electric water heater"

Dear Jim: My electric water heater is 18 years old, but still works. I want to reduce my water heating costs. What can I do to make it more efficient? Do you have any tips for selecting a new one? - Marc H.

Dear Marc: New water heaters are more energy efficient than old ones like yours, but many homeowners cannot afford to replace an older less efficient one. For a typical family or four, it is not unusual for water heating to consume 20 to 25 percent of the total annual energy usage.

Electric water heaters are simple devices. There are two electric resistance heating elements, top and bottom, in the water tank. They are not on at the same time because that would draw too much electric current. The bottom one is used to keep the tank water hot. When the tank starts to run out of hot water after many long showers, the top element comes on instead to supply hot water faster.

From the energy-usage standpoint to heat the water, all electric water heaters, even old ones, have nearly 100-percent heating efficiency. All the electricity used end up heating water because the heating elements are submerged. The difference in the overall efficiency and your water heating costs are determined by how much heat is lost from the water tank.

In old water heater tanks, the lower heating element has to come on fairly often just to make up the heat lost through the insulation to the surrounding air. The most energy efficient electric water heaters have many inches of high-R-value insulating foam in between the water tank and the outer skin. Your water heater probably has just a couple of inches of fiberglass insulation.

The efficiency can be increased by adding tank insulation. Test your water heater tank to see if it needs more insulation. Place your hand on other metal objects in your basement or utility room to get a sense for their temperature. Next, put your hand on the water heater tank near the top. I bet your old water heater will feel much warmer because it is losing heat.

Water heater insulating jackets are available at most home center stores. These wrap around the tank and cover the top. R-13 fiberglass batt wall insulation also works well. Face the vapor barrier to the outside and covered this with construction foil to also create a low-emissivity barrier. When insulating a gas water heater, do not to block the combustion air inlet at the bottom and the draft diverter at the top.

Your water heater probably does not have heat trap fittings in the inlet and outlet pipes as new water heaters do. Hot water, because it is less dense than cold water, naturally circulates up into the section of the pipes above the water heater. This hot water loses heat and drops back down. This continuous convection current wastes energy.

Put tubular foam insulation over the pipes immediately above the tank to minimize this heat loss. You can also have heat trap fittings installed in your old tank to stop this.

Although it is not as important with an electric water heater as it is with a gas one, drain a gallon of water from the valve at the bottom of the tank every several months. If you have never done it before, you will likely see a lot of sediment come out.

Check the temperature of the hot water at the kitchen faucet with a thermometer. You will find two covers on the side of the water heater over the heating elements and thermostats. Switch off the circuit breaker and adjust the thermostats. Switch the power back on and let the temperature stabilize. A temperature of 110 to 120 degrees is adequate.

Install a water heater timer to switch it off during the daytime when away working. The water will stay reasonably hot. Set the timer to come back on late at night. This helps your electric cooperative control peak demand. Check with your cooperative about incentive programs for them to install a timer which they can control during peak times.

If you end up deciding to get a new electric water heater, select a 12-year warranty model. These have higher R-value foam insulation in the tank walls than a cheaper 6-year model. Also, most of the 12-year models have accurate electronic digital controls. They also have a vacation-mode to save electricity when you travel.

Dear Jim: During winter, a small gap forms where the walls meet the ceiling and I am afraid that it leaks air. During summer, it disappears. What causes this and how can I stop it? - Rhonda L.

Dear Rhonda: During winter, temperature differences between the exposed truss top members and the bottom members buried in the attic insulation cause the gap to form. These thermal stresses create truss uplift.

This gap can leak some indoor air into the attic. It can be quite a job to fix it permanently. The easiest method to correct it now is to just nail a molding strip to the ceiling. This looks better and blocks most of the air leakage.

Send inquiries to James Dulley, Publication Name, 6906 Royalgreen Dr., Cincinnati, OH 45244 or visit www.dulley.com.