Thomas W Santa Rosa , CA July 03, 2017 Appliance: Thermador RDSS30 S/N 9707 & UP 1 burner not working 1 would not "simmer" Replaced potentiometers, simmer control unit, and 2 solenoids. Could have been a fairly easy project, except 1 of the venturi's had "seized" preventing even the removal of the range top. After attempting to use an "easy out", which failed, I had to drill out the brass venturi, destroying it, and the jet assembly below. Once the range top was removed, the rest of the repair went well. Took photo's of all the wiring connections to ensure I put it back together correctly. All burners are back to functioning as designed - simmer works on the 2 left side burners. Used anti seize lubricant to re-install the new venturi. 8 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 1-2 hours