Washington State Conservation Fact Sheet

• Project Type: General OWC
• Applicant: Grand Junction - City of
• Project Name: Grand Junction Retrofit Pilot Project
• Title: Hot Water Conservation Fact Sheet
• County: Mesa
• Water Conservation - Doc Type: Reports

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INCREASING WATER HEATING SYSTEM EFFICIENCY

In addition to reducing the demand for hot water, there are a number of measures you can take
to improve the efficiency of your hot water system.

. Turn Down Temperature on Hot Water Tank

Many water heaters come from the manufacturer with the thermostat set at 1500F or higher. If
you can't comfortably hold your hand under the hot water as it comes from the tap, chances are
that your thermostat is set too high. Hot water temperatures greater than 1300F are not
necessary and can cause scalding problems. At 150o scalding time is two seconds, while at 1300
it is 30 seconds.

High thermostat settings, besides being dangerous, will cause your water heater to lose heat at a
much more rapid rate than would occur if the temperature was kept lower. This is because the
rate of heat loss from an object increases as .the temperature difference between the object and
the surrounding air increases. This can be f.airly significant since most hot water tanks keep 50
to 80 gallons of water hot 24 hours a day.' A lower temperature setting will also reduce the rate
of oxidation. Oxidation contributes to tank failure, therefore, by lowering the temperature you
will increase the life of your tank.

You can minimize heat loss from your hot water tank by setting your thermostat at 1300F, If
your thermostat is currently set at 1500F and your tank holds 60 gallons, you can expect to
reduce your energy demand by about 10 percent. Here's how to do it if you have an electric
water heater:

1. Turn off y'our circui t breaker or remove fuses
to break the circuit to the heater.

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2. Remove the cover plates that cover the
thermostat. Most electric water heaters have
two thermostats: one at the bottom of the
tank, and a second about two-thirds of the way
up the tank. Sometimes a Phillips head
'screwdriver is needed.

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3. Caution should be taken at all times when the
coverplates are off. It will be safest if you
treat the heater as if it still has current
running through it. Push the insulation aside
using something nonconductive. Use a flat
blade screwdriver with an insulated handle to
turn each thermostat so that the pointers are
set at l300F. Make sure both pointers are set
at the same number. Do not touch the brass
screws that hold the wires when making the
adjustment.

4. Push the insulation back over the thermostat and replace the cover plates. Turn on the
power at the fuse box or circuit breaker.

5. Check the temperature at the tap on the following day using a meat or candy thermometer.
Differences between the actual temperature of the water at the tap and the thermostat
setting can be the result of how accurate your thermostat is and heat loss through the water
pipes. If the temperature at the tap is not satisfactory, adjust the thermostat accordingly.

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