SERVICE PROCEDURE RE-III
Residential Thermostat Testing
WARNING
High voltage exposure. Use caution to avoid
personal injury during this procedu re.
Illustration 6
Single ElementOperation or
Double Element, 4 Wire, Simultaneous,Single Phase
Operation.
Water In Tank Is Cold With Power ON.
1. This procedureassumes line voltage, ECO and
elements are in working order.
2. Turn power “ON” to water heater.
3. Set multi-meter to “Volts AC”.
4. Check acrossterminals L4 and T2 of
thermostat (see illustration 6).
A) Rated voltageNOT present,
Recheck ECO. If ECO is okay,
replace thermostat.
B) Rated voltageIS present,
proceed to next step.
5. Check acrosselement terminals
(see illustration 7).
A) Rated voltageNOT present,
check wire connections from
thermostat to element.
B) Rated voltageIS present,
Repeat element testing
see page 15.
Illustration 7
Water Temperature In Tank Is Above Thermostat Setting.
1. This procedureassumes line voltage, ECO and
elements are in working order.
2. Turn power “ON” to water heater.
3. Set multi-meter to “Volts AC”.
4. See illustration 6 above, check across terminals L4 and T2
of thermostat.
A) Rated voltageIS present,
replace thermostat.
B) Rated voltageNOT present,
thermostat is okay.
C) Lower than rated voltage IS present,
recheck for grounded element
(see page 15).
Reference 4 Wire, Simultaneous,Single Phase
Wiring diagram.
NOTE: Wiring consists of two s ingle element configuratio ns
operating independently .
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