Bradford-White Corp M-2-50T6DS SERVICE PROCEDURE RE-IV Light Duty Commercial Thermostat Testing, Page 25

SERVICE PROCEDURE RE-IV
Light Duty Commercial
Thermostat Testing
WARNING
High voltage exposure. Use caution to avoid
personal injury during this procedure.
Double Element, Non-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
upper thermostat (see illustration 29).
A) Rated voltageNOT present,
Recheck ECO (see page 14). If
ECO is okay, replace thermostat.
B) Rated voltageIS present,
proceed to next step.
5. Check acrosselement terminals
(see illustration 30).
A) Rated voltageNOT present,
check wire connections from
thermostat to element.
B) Rated voltageIS present,
Repeat element testing
see page 15. Illustration 29 Illustration 30
Tank Does Not DeliverE nough Hot Water.
1. This procedureassumes line voltage, ECO and elements are in
working order.
2. Turn power “ON” to water heater and set multi-meter to “Volts AC”
3. Adjust temperature settingof upper & lower thermostat to the
Highest setting. Water temperature in tank must be belowthermostat
setting for this test.
4. See illustration 29 above. Check voltage across terminals L4 & T2 of
upper thermostat.
A) Rated voltageIS present, okay, upper thermostat is calling
for heat. Go to step5 below.
B) Rated voltageNOT present, replace upper thermostat.
5. Adjust temperature settingof upper thermostat to the minimum
setting. Water temperature in tank must be above thermostat setting
for this test.
6. Check voltageacross terminals L3 & T4 of upper
thermostat (see illustration 31).
A) Rated voltageNOT present, replace upper thermostat.
B) Rated voltageIS pres ent, upper thermostat is okay. Go to
step 7 on next page.
Illustration 31
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