I own a 2012 model 3100. My low point drains are located under the bottom drawer under the sink. Pull that drawer out and there should be a lever on each side of the slide rail of the drawer. Mine are black. Lift one up. Push the other down and you can remove that drawer. You should see two "T" handles. Don't turn. Pull levers up.
do not pull the oval valve handles. The pipes are in the shape of an "H" - the feet of the H, closest to you, turn down and go through the floor. Those are your low drains. The little "T" shape valve is just before the elbow bend toward the floor. One for each leg.My bypass valves are oval silver and turn. My low drain valves match the pipes and pull up.Note: low drain is low spot when level.