Electronic (solid-state) ignition systems have been developed to improve the energy efficiency of gas furnaces, boilers, and water heaters. These electronic ignition systems replace the less energy-efficient standing pilot used in traditional gas-fired appliances. There are three different types of controls used in electronic ignition systems:
• Intermittent pilot ignition module
• Direct ignition gas module
• Hot-surface ignition module
Ignition modules do not have replaceable parts. If defective, the entire unit must be replaced. A replacement module must be of the exact same model and type as the defective one.
Manufacturers of electronic ignition modules offer a wide range of models designed to fit a variety of different applications (see Figure 5-64). Always make certain that the make, model, and operating specifications of the original gas valve control module match those of the replacement one. Specification sheets and installation instructions for electronic ignition modules are available online at the manufacturer’ s Web site or by writing directly to the manufacturer.
The following three sections briefly describe the three types of electronic ignition modules used in gas-fired furnaces, boilers, and water heaters. For more detailed and model-specific information, consult the owner’ s manual, installation manual, and/or the specification/data sheets provided by the manufacturer.