Ohms Check - A.O. Smith TC-049R3 Service Handbook

RESIDENTIAL GAS AND ELECTRIC WATER HEATER
Residential Electric – continued
Testing A-6 - two element, two thermostat, one high limit, two wire circuit type water
heaters.
Wired non-simultaneously – When the upper element satisfies, power switches to the
lower thermostat and element.
Element Test
OHMS Resistance Check**
Test Conditions:
This test uses the multimeter's battery as the electrical
supply.
Power to the water heater is "OFF".
Multimeter set to OHMS scale testing.
Black lead "Common" port.
Red lead in "Ω" or " OHMS" port.
Dial indicator set to scale above expected indication.
Note: Volts divided by amps = OHMS
Disconnect wires from the element terminals.
Test probe on each terminal of an element
See OHMS Resistance Table – Page 45
If ...
proper resistance (+7.5%) is
present
meter reads "0"
meter reads "1" or off scale
** The above test can also be conducted with the element removed from the tank.
A.O. Smith Water Products Company
©2005
SERVICE HANDBOOK
A-6 Circuit Servicing
... then
continue testing.
• check OHM scale setting.
• replace element.
replace element.
42
Element
Technical Training Department
Ashland City, TN