A.O. Smith Water Heater Piezoelectric Igniter System, Testing the Igniter System

7.Reconnect the igniter wire.

8.Turn gas supply on and refer to the Lighting Instruc- tions.

,With the burner lit, check the gas control valve/ thermostat supply line, two piece wire connector, manifold tube, and pilot tube connections for leaks. Check for leaks by brushing on an approved noncorrosive leak detection solution. Bubbles forming indicate a leak. Correct any leak found. IMPORTANT: All leaks must be fixed immediately.

10. Replace the outer door.

FLAMEARRESTOR BRACKET

DOOR GASKET

TIP

FIGURE 30.

CLOSE-UP INSIDE VIEW OF

THE COMBUSTION CHAMBER.

l

BRACKET

MANIFOLD TUBE

FIGURE 31.

Piezoelectric Igniter System

The piezoelectric igniter system consists of the igniter button, electrode, and wire. The pilot is ignited by an electric spark generated when the igniter button is pressed. The spark gap of 0.125 inch is set when the electrode is installed at the factory. (Figure 32 ). Use only factory authorized piezoelectric igniter parts for replacement.

IGNITER

BUTTON

		THERMOCOUPLE
		/2P,LOT
-WIRE	PILOT _	\ TIP
/ TO
	BRACKET/.	ELECTRODE
ELECTRODE

SNAP-ON CONNECTOR

*NOTE: SPARK GAP DISTANCE MEASURED FROM ELECTRODE TIP TO PILOT.

FIGURE 32.

Testing the Igniter System

Turn off the gas to the water heater at the manual gas shut-off valve. Watch the electrode tip while activating the igniter. A visible spark should jump from the electrode. To avoid shock, do not touch the burner or any metal part

on the pilot or pilot assembly. If no spark is visible, check the wire connections and make sure the electrode is not

broken. Replace the igniter if defective. Dirt and rust on the pilot or electrode tip can prevent the igniter spark. Wipe clean with a damp cloth and dry completely. Rust can be removed from the electrode tip and metal surfaces by lightly sanding with an emery cloth or fine grit sandpaper.

Removing and Replacing the Gas Control Valve/Thermostat

IMPORTANT: This water heater has a resettable thermal switch installed. Do not attempt to disable or modify this feature in any way. Use only factory authorized replacement parts.

Removing the Gas Valve:

1.Turn off the gas supply to the water heater at the manual gas shut-off valve. This valve is typically located beside the water heater. Note the position of the shut-off valve in the open/on position then proceed to turn it off (Figure 3).

2.On the lower front of the water heater locate the gas control valve/thermostat (see Figure 23). Before performing any maintenance, it is important to turn the temperature dial on the gas control valve/thermostat to its lowest setting.

3.On top of the gas control valve/thermostat turn the gas control knob to the "OFF" position. NOTE: On the Robertshaw gas control valve/thermostat the knob stop must first be depressed before turning the gas control knob. See Lighting Instructions on the water heater.

4.Drain the water heater. Refer to the section of "Draining and Flushing" section and follow the procedure.

5.Disconnect the igniter wire from the igniter. NOTE: There are two types of igniters. If you have the square igniter, slide the igniter bracket backwards away from the gas valve to remove it. If you have the round igniter, first remove the igniter from the bracket by depressing front and rear holding tabs and lift. Next remove igniter bracket from the gas valve. Disconnect the thermocouple (right-hand threads), pilot tube, and manifold tube at the gas control valve/thermostat (Figure 22). NOTE: L.P.

gas systems use reverse (left-hand) threads on the manifold tube.

,Refer to "Gas Piping" section (Figure 3) and disconnect the ground joint union in the gas piping. Disconnect the remaining pipe from the gas control valve/thermostat.

,To remove the gas control valve/thermostat, thread a correctly sized pipe into the inlet and use it to turn the gas control valve/thermostat (counterclockwise.) Do not use pipe wrench or equivalent to grip body. Damage may result, causing leaks.

Do not insert any sharp objects into the inlet or outlet connections. Damage to the gas control valve/thermostat may result.

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