Service Procedure X: Transformer Replacement - Bradford White EF120T4003N3 Service Manual

Transformer Replacement Procedure
1. Position main power switch to OFF.
2. Disconnect (unplug) water heater from 120 volt power source.
3. Unlatch and remove surround cover from top of water heater.
4. Disconnect primary leads (black and white) and secondary leads (blue and yellow) from the transformer
(connections are different sizes to prevent interchanging).
5. Remove the 2 nuts (7/16" nut driver) holding the transformer in place and remove transformer from control board
(see image below).
6. Install new transformer and secure in place with screws from Step 6.
7. Reconnect primary and secondary wires to the transformer (leads are different sizes to prevent interchanging).
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 instructions located in the Installation and Operating Manual.
9. Replace the surround cover on the top of the water heater.
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Service Procedure X:
Transformer Replacement
Black &
White wires
Blue &
Yellow wires
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WARNING
120 volt potential exposure. Use
caution making voltage checks
to avoid personal injury.