Bradford White DB-80R3DS - Manual (Page 32)

SERVICE PROCEDURE RE-IV
Light Duty Commercial
Thermostat Testing
WARNING
High voltage exposure. Use caution to avoid
personal injury during this procedure.
Double Element, Simultaneous, Three Phase
Operation (continued).
Water Temperature In Tank Is Above Thermostat
Setting.
1. This procedure assumes line voltage, ECO and
elements are in working order.
2. Adjust upper and lower thermostat to the lowest setting.
3. Turn power “ON” to water heater.
4. Set multi-meter to “Volts AC”
5. Check across terminals L4 and T2 of
upper thermostat (see illustration 51).
A) Rated voltage IS present,
replace upper thermostat.
B) Rated voltage NOT present,
upper thermostat is okay. Go to step 6 below.
C) lower than rated voltage IS present,
recheck for grounded upper element
see page 15.
6. Check across terminals L4 & T2 of lower thermostat
(see illustration 52).
A) Rated voltage IS present,
replace lower thermostat.
B) Rated voltage NOT present,
lower thermostat is okay.
C) lower than rated voltage IS present,
recheck for grounded lower element.
Illustration 51
Illustration 52
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