Service Procedure Xii: Transformer Replacement - Bradford White UCG100H3993N Service Manual

Transformer Replacement Procedure
Step 1. Position main power switch to "OFF."
Step 2. Disconnect (Unplug) water heater from 120 Volt
power source.
Step 3. Un-latch & remove surround cover from top of water
heater.
Step 4. Disconnect primary leads (black & white) and secondary leads (blue & yellow) from the transformer.
(connections are different sizes to prevent interchanging)
Step 5. Remove the 2 nuts (7/16 nut driver) holding the transformer in place and remove transformer from control
panel. (see photo below)
Step 6. Install new transformer and secure in place with screws from step 6.
Step 7. Reconnect primary and secondary wires to transformer (leads are different sizes to prevent interchanging).
Step 8. Restore 120 volt power supply to water heater and confirm proper operation following the lighting instructions
on the lighting instruction label or the lighting instruction located in the installation and operating instruction
manual.
Step 9. Replace surround cover on top of water heater.
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Service Procedure XII:
Transformer Replacement
120 volt potential exposure. Isolate the
appliance and reconfirm power is disconnected
using a multi-meter.
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WARNING