Safety Alert for Lift with defective Worm Gear

A safety alert is issued to warn of elevator lifts with defective worm gear following a fatal accident in the Netherlands.

Description:  Ziehl-Abegg Elevator with worm gear of Type / Model No:  ZAS0, ZAS1, ZAS2, ZAS3

defective worm gear

Reference – Notification to EU rapid alert system for dangerous products (RAPEX). Rapex Alert no. A12/1214/19 which can be viewed here

Risk: It has been identified that one or more of the six hard steel nuts which secure the worm gear to the flange from the axle to the traction sheave may become loose. The worm gear may thus become detached from the drive shaft and result in an uncontrolled movement of the lift cabin.

The Authority wish to bring this safety alert and relevant information to the attention of owners and users of this lift type as well as maintenance and inspection personnel.

Measures to be taken:

  • Elevator lift installations with this worm gear should be taken out of use until an inspection by a competent engineer has been carried out and any necessary remedial action taken.
  • Elevator maintenance and inspection personnel to check security of nuts during inspection / maintenance. 

Please notify the HSA should you come across this product, at LoCall: 1890 289 389 or email

Further Information:

The elevator lifts in question were marketed by Ziehl-Abegg between 2012 and 2018. These machines are used in elevator installations with a separate engine room and can be recognized by the grey color in combination with a bright yellow traction sheave. The shortcoming does not occur for other ZA types. For more information you should contact the manufacturer at: