Simplex 900 Series User Manual

11. Replace the screw on the top of the lock housing.
[Note: The outside thumbturn cannot be forced to retract the latch / bolt because it is connected to the lock
housing by a friction clutch. If the thumbturn has been forced, it can be turned back to the vertical position by
hand without damaging the lock.]
Troubleshooting
Symptom/problem: Turning outside thumbturn always retracts latch/bolt without depressing without any
buttons.
Cause: Lock is in zero combination.
Solution: Follow the procedure for changing a combination, but omit step 2.

Simplex 900 Series Specifications

General

Key Override	Optional
Door Thickness	1-3/4" to 2-1/4"
Backset	2-3/4"
Number of Codes	Not applicable
Code Length	Not applicable
Finishes	Satin chrome
Operating Temperature	-4°F to 150°F (-20°C to 66°C)