Service Procedure Iv: Hi Limit Switch Testing - Bradford White ElectriFLEX HD CEHD 50 Service Manual

Single Phase Line Voltage Testing
1. This procedure assumes line voltage, transformer, fuses,
and thermostat are in working order.
2. Turn power "OFF" to water heater.
3. Open door or remove lower panel, and remove insulation
from inside of the control box.
4. Check for continuity across terminals 1 & 2.
(See illustration 6)
A. Continuity IS present, Hi Limit Switch is okay.
B. Continuity NOT present, proceed to step 5.
5. Verify power to the heater is "OFF", firmly press the Hi Limit
switch reset button. Recheck continuity across terminals 1 &
2. (see illustration 6)
A. Continuity IS present, the Hi Limit Switch has
previously opened indicating the water in the tank,
at some point, did overheat. Check the following:
1. Be sure heating element(s) is not shorted to
ground (see page 12).
2. Proper thermostat operation (see page 16).
B. Continuity NOT present, water in tank may be over
heated.
1. If water is overheated, verify that power to
water heater is "OFF". Flow water through
the tank to cool below set point of the
thermostat. Reset Hi Limit Switch and
recheck continuity.
2. If water is cool, replace Hi Limit Switch.
Service Procedure IV:
Hi Limit Switch Testing
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WARNING
High voltage exposure. Use caution when making
voltage checks to avoid hazard to life or property.
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