Here we show how to repair a Grundfos Medium CR, CRI, and CRN pump. This includes the 10, 15, and 20 series pumps. This video shows how to change the mechanical seal, impeller/chamber "stack kit" assembly, and o-rings. The model shown is a CR10-10.We are a factory authorized service center for Grundfos for the state of Florida with a warehouse in Orlando. This is for instructional purposes only.For more information see our website at www.blumenauerpumps.com