Many Bosch stoves are manufactured with an on-board component designed to automatically ignite gas as soon as a control tap is switched on; this component is called a "spark module." Spark modules are not intended to create sparks when burner control taps are switched to "Off" or when the burners are lit; either behavior is a malfunction.
Bosch products are sold in more than 100 countries worldwide. In common with most modern marques, Bosch manufactures stoves with self-igniting hot-plate and oven burners; both gas-only and dual-fuel models are fitted with self-igniting burners. Bosch warranties all its products for 12 months from the date of purchase; replacement of a malfunctioning igniter module, after that period, is the responsibility of the owner.
The cause of incessant sparking is invariably a malfunctioning spark module. Spark modules are sealed electronic components that interpret information from sensors and switch the sparking function on and off accordingly. There are no user- or professionally-serviceable parts inside a spark module; a malfunctioning unit must be replaced.
Constant sparking can be temporarily stopped by unplugging the stove from its power outlet. This is intended only to stop the irritating noise; the root problem must be addressed immediately. Disable the gas connection as well. Unignited gas from a tap that is accidentally turned on can very quickly build up to dangerous levels. Unplugging the stove will also keep many of its other functions, including the timer and integral lighting, from working.
Troubleshooting and Ordering Parts
Plug the stove back into the electrical supply to make the diagnosis. Determine where on the stove the constant sparking noise is coming from. Bosch stoves use a single igniter module for all self-igniters on the stove-top burners and separate units for the main burner and the broiler-grilling burner in the oven. Write down the name and model number of the stove; the name is typically printed on the visible parts of the stove while the model number is likely embossed on a metal plate attached to the rear. Obtain a replacement spark module from a home improvement warehouse that stocks Bosch products or order one from Bosch or an electricians' supply company.
Spark modules are simple to replace. Ensure that the stove is still disconnected from the power outlet. Locate the malfunctioning module. The packaging or instructions supplied with the replacement module should stipulate where to look; typically, the spark module is under the cook top or toward the back of the receiver into which the storage drawer slides. Hold the new and old modules side-by-side, pull a wire from a terminal on the old unit then fit it onto the corresponding terminal on the new unit. Work one wire at a time. When all of the wires are swapped over, retract the two screws that hold the old unit to the stove, discard it and screw the new unit in place. Restore the electrical supply to the stove.