SERVICE PROCEDURE MCE-VIII
Thermostat Testing
Water In TankIs Cold With PowerON.
1. This procedure assumes line voltage , ECO, transformer
thermostat, and elements are in working order.
2. TURN OFF POWER TO WATER HEATER.
3. Remove access cover from lower control box.
Remove insulation from inside of control box.
4. Using a phillips head screw driver, disconnect the wire lead at
terminal 2 of the thermostat. Only check one thermostat at a time
to insure wires are correctly reinstall ed upon completion.
Mark wires if necessary for reinstallation.
5. Set multi-meter tocheck continuity.
6. Check continuity across terminals 1 & 2 of thermostat
(see illustration 11).
A) Continuity NOT present, replace thermostat.
B) Continuity IS present, thermostat is okay.
Water Temperature In Tank Is Above Thermostat Setting.
1. This procedure assumes line voltage, ECO, thermostat, transformer, and
elements are in working order.
2. TURN OFF POWER TO WATER HEATER.
3. Remove access cover from lower control box.
Remove insulation from inside of control box.
4. Using a phillips head screw driver, disconnect the wire lead at
terminal 2 of the thermostat. Only check one thermostat at a time
to insure wires are correctly reinstalled upon completion.
Mark wires ifnecessary for reinstallation.
5. Set multi-meter to check continuity.
6. See illustration 11 above, check across terminals 1 & 2 of thermostat.
A) Continuity IS present, replace thermostat.
B) Continuity NOT present, thermostat is okay.
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600V Surface Mounted Thermostat Models.
Operation Testing DANGER
High voltage exposure. To avoid hazard to
life or property, use extreme caution when
making voltage checks .
Illustration 11
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