A question about Bosch NGM5024UC/03 cooktop.
When I turn one knob on, igniters for all burners start sparking. They stop after the gas lights up.
Is this normal or should only one igniter spark at a time?
If this is not normal, what could be causing this?
Stevekauss, this is normal behavior in this case. When a burner is turned on, it sends 120VAC to the spark module (all switches will send voltage to the same spot) and the spark module will send voltage to all of the electrodes until it "senses" that a flame has ignited.
— Begin quote from WilliamM/APP Team;927098
Stevekauss, this is normal behavior in this case. When a burner is turned on, it sends 120VAC to the spark module (all switches will send voltage to the same spot) and the spark module will send voltage to all of the electrodes until it "senses" that a flame has ignited.
— End quote
I read that this "sensing" is done by thermocouple. I checked the parts diagram for this cooktop here-
https://www.bosch-home.com/us/supportdetail/product/NGM5054UC/03#/Tabs=section-spareparts/
It does not show any thermocouple. Is it using another technology?
The spark module has a grounding wire that is used to help "sense" current. When the spark module sends voltage out, the electrodes will send the voltage through the grounded burner head. When a flame ignites, the resistance of the burner head changes, allowing the small amount of leftover voltage to pass through and be sensed by the spark module through its ground wire.