A.O. Smith 100 Series, Руководство по обслуживанию

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Servicing should only be performed by a Qualified Service Agent
SPARK IGNITER
The Spark Igniter is made of a ceramic composite material, see Figure 11 below. The Control System powers the Spark Igniter (120
VAC) from the pin 6, J5 connector on the Control Board to the External Spark Transformer.
Spark Igniters are service parts, over time Spark Igniters will wear out and must be replaced as they will no longer generate enough
spark to cause ignition.
Before troubleshooting the Spark Igniter it is recommended to check the reasons for ignition failure such as no gas, air in the gas line,
gas supply pressure being too low or improper air-gas mixture caused by incorrect gas valve setting. Only when it is identified that
ignition failure is not caused by these reasons, troubleshooting the Spark Igniter is recommended.
External Ignition System Components:
The three main components of the spark ignition system are the Burner Control Board, the Ignition Transformer and the Spark Igniter.
The Burner Control Board sends 120 VAC to the Ignition Transformer during the pre-ignition and startup cycle only. The Ignition
Transformer takes the input voltage and outputs the ignition voltage as high as 14 kV to the Spark Igniter for reliable ignition.
Service Notes/Troubleshooting the External Ignition System:
• Turn OFF all the gas supply valves internal and external to the unit (Turn ON only when safe and before ignition tests).
• Identify the pin 6 on the J5 connector block, using a voltmeter measure the volts on this terminal with reference to ground
during the pre-ignition/start up cycle of the boiler/water heater. Use the display to exactly time the ignition cycle (Burner state:
Pre-ignition, as the sparker does not operate continuously). This should read approximately 115-120 VAC. If the voltage range
matches, then the Ignition Transformer or the Spark Igniter could be causing the failure. If there is no voltage during the ignition
cycle, then check pin 7 on J5 connector for the supply voltage of 115-120 VAC. The pin 7 on J5 connector is connected to the
main power terminals.
• If there is voltage at pin 6 on J5 connector, replace the Ignition Transformer and retest. If it still fails, reaplce the Spark Igniter
and test.
FIGURE 11. SPARK IGNITER