If you have a Z1 showing a Fault 33 or 21 it means that the internal battery has stopped working and can no longer save data in its memory. Please be aware that the life span on all batteries is limited. Most likely the Z1 is outside of the warranty period. If the manufacture date, located on the back of the unit under the serial number is after 2015-03, then your unit is  repairable. If the device was manufactured before 2015-03, it can no longer be repaired, as improvements to the design after that date make the old parts incompatible with the newer parts.

Please contact us at 855-436-8724 about replacing or repairing your device.