How Do I Troubleshoot My AO Smith Electric Water
Heater
Troubleshooting and
repairing an AO Smith electric water heater only takes a few minutes, and can save you hundreds in service calls
and plumbing bills. The main indications of electric water heater problems are; no hot water, not enough hot
water, slow hot water recovery, overheating and loud or unusual noises. Each of these problems has its own cause
and repair requirements. We recommend calling a professional; however, you can repair most hot water heater
complications yourself. Remember, if your water heater is still under warranty, or you are not sure, call the
1-800 number on your AO Smith water heater and ask for help and parts free.
Make sure the main electric
circuit breaker(s) or fuses are in their “On” position inside the home’s main electric panel. If a breaker(s)
looks to be half on and half off, close the breaker and open it rapidly. If the breaker does not stay in the on
position, replace the water heater breaker(s) and/or inspect the wiring from panel to heater. We recommend
contacting a licensed, bonded and insured electrical contractor to troubleshoot the
problem.In some cases, a bad breaker is a sign of trouble within the wiring system or water heater
itself.
Testing AO Smith Electric Water Heater
Thermostats
Turn off all circuit
breakers and/or disconnect the fuses. Remove the thermostat cover plate(s) with a Phillips screwdriver. Turn the
power back on.
Check for incoming power
using a voltmeter. Set the meter to read 250 Volts. Touch and hold one lead wire to each of the top left and
right screws of the top thermostat (or top two screws of the lower, if only one thermostat is present.) The
meter should read approximately 210 to 230 volts of electricity. If no voltage is present with the breakers and
fuses on, contact an electrician.
Turn on all the hot water
faucets in the house until the water runs cold. This will ensure that the thermostat(s) will call for
heat.Turn
the faucets off.
Place one lead of the
voltmeter on the top left thermostat screw and one lead on the second screw down on the right side of the
thermostat. There should be 210+ volts of power. If not, turn the power off to the heater and push in firmly on
the red reset button in the middle of the thermostat. You should here a click (but not
always.)
Turn the power back on and
check for voltage again. If no power, or limited power- fewer than 210 volts are present, check the top
water-heating element for proper operation. If full power is present, but you still have no hot water after an
hour or two, replace the top heating element. If no voltage, replace the thermostat.
Testing the AO Smith Electric Water Heater Heating
Elements
Turn the power off to the
water heater; remove the cover plate(s).
Test for incoming voltage
with your voltmeter. Do not proceed until you verify that no voltage is present.
Loosen the two screws on
each side of the heating element with a Phillips screwdriver.
Wearing heavy, electrical
certified gloves remove each wire from the heating element and bend it slightly back out of the way.
Set your multi-meter to the
Ohms position.
Place one lead on each screw
of the element. The Ohm or resistance should read 12 to 16; averages are 13 to 14. If the reading is below 12
ohms of resistance, replace the water-heating element.
Reinstall the element’s
wiring.
Turn the power back on and
test the circuit again. Reset your voltmeter to 250V. Full power should now be present. Turn the power off and
replace the front cover(s).
Turn the water heater power
on and wait an hour or two to check the hot water temperature at several faucets. The recovery time of an
average AO Smith residential elect water heater is around 22 gallons an hour. It may take a while to reheat,
depending on the size of your unit;