While you wait for answers, we may have found some information which could help you.
Click here for Replace Cord Electriceureka 4870B smartboss, upright vaccum?
Eureka 4870 vacuum?
How to fix idler clamp assembly (hardwood/carpet switch) on Eureka SmartVac?
how can i fix eureka boss capture?
how can I fix my Eureka 431?
Eureka "boss" #5893 stops sucking after 10mins?