When RR knob is turned to "spark", there is no spark on RR burner. But, when I turn R front knob to "spark", both RR and RF burner spark - since there is no gas to RR burner (since that knob is "off") the RR burner doesn't light. In order to light the RR burner, I have to turn RF knob to "spark" and simultaneously turn on RR burner. The unit is 3 yrs old and the RR burner has always been a little "touchy" when lighting. Only in the last week has it totally stopped sparking.

Cooktops - Dacor - Preference SGM365SS Gas Cooktop