Transformer Removal / Replacement - A.O. Smith 12 40GPC T 100 Service Handbook

Standard residential high efficiency atmospheric vent (fvir) gas water heaters

Hide thumbs

Table Of Contents

Table of Contents

Important: Use only factory authorized replacement parts.

If you lack the necessary skills to properly perform the

installation, you should not proceed, but get help from a

qualified service technician.

Tools required: Ratchet with

Driver, Phillips Head Screwdriver.

Removing the Transformer:

1. Set the gas control valve/thermostat to its lowest

setting by pressing the "COOLER" and "HOTTER"

buttons together at the same time holding for 1

second. Then press the "COOLER" button to the

lowest setting (Figure 40).

2. Turn gas control switch to the "OFF" position

(located right side of the gas control valve/

thermostat) and turn off the gas supply to the unit

(Figure 41).

3. Disconnect the electric connection by unplugging

the transformer from the wall outlet (Figure 41).

4. Remove the manifold cover outer door from the

heater by depressing on the lower portion and

pulling outward.

5. Unplug the power supply transformer connector

from the bottom of the gas control valve by

pressing the snap connector and pulling

downward (Figure 42). (NOTE: The transformer is

located inside the transformer box adjacent to the

gas control/thermostat valve).

6. Using a phillips head screwdriver, remove the

transformer box from the side of the water heater

by removing the single screw securing it to the

water heater's side (Note: keep screw in a safe

place for reinstalling later).

7. Using a phillips head screwdriver remove the

ground screw from the inside of the transformer

box (Note: save the screw for reinstallation later)

(see Figure 43).

8. Take note of the position of the transformer, use

a 5/16" nut driver or a ratchet with a 5/16" socket

to remove the 2 hex head screws on the front of

the transformer box (Note: save the screws for

reinstallation later) (see Figure 43).

9. Unplug the two flag terminal electrical connections

on the transformer and pull the wiring and

connector through the wire protector (Figure 43).

Figure 42.

GAS CONTROL

VALVE/THERMOSTAT

Valve/Thermostat

POWER SUPPLY

Gas Valve

TRANSFORMER

Wire Connector

CONNECTOR