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Servicing should only be performed by a Qualified Service Agent
19
OPERATION & SERVICE
Thermostat & ECO Test
1 Secure power to the water heater at the main breaker or disconnect switch.
2 Ensure tank temperature is less than 100°F/38°C - dump water to lower tank temperature if necessary.
3 Press the red reset button firmly on all thermostat/ECO controls.
4 Raise the temperature setting on all thermostat/ECO controls to 140°F or higher.
5 Restore power to the water heater.
6 With an AC volt meter check for voltage between the L1 and L3 terminals on the control - see illustrations
below. Measured voltage should match the power supply to the water heater.
Service Note: If the measured voltage is zero volts or not the correct voltage ensure heating element
power circuit wiring is correct (see wiring diagram on water heater) check fuses (page 17) and/or restore
power to the water heater - see pages 12 - 14.
7 With an AC volt meter check for voltage between the L4 and T2 terminals on the control - see illustrations
below - if the measured voltage matches the power supply to the water heater the ECO is resetting
properly. If the measured voltage between L4 and T2 is low or not present the control is defective - replace
the control.
Service Note: Grounded heating elements, defective thermostats and/or a defective ECOs can all cause
frequent ECO activation. If an ECO is being frequently reset on any of the thermostat/ECO controls check
all heating elements to ensure they are not grounded (see page 26) first. Replace any grounded elements.
If no elements are grounded replace the thermostat/ECO control(s) that require frequent resetting.
L1 L3
L4
T2
L1 L3
L4
T2
STEP 6 CHECKING POWER TO THE CONTROL
STEP 7 CHECKING POWER TO THE HEATING ELEMENT