While you wait for answers, we may have found some information which could help you.
Click here for Suction Full Vacuumhow can I fix my Eureka 431?
Eureka "boss" #5893 stops sucking after 10mins?
how can i fix eureka boss capture?
Eureka Boss Smart Vac Thermal Cutoff ?
Eureka Model 4870 Motor Replacement?
eureka 4870B smartboss, upright vaccum?