Simplex 900 Series User Manual

9. Resecure the combination change plug assembly by screwing it in clockwise with the DF-59 key — do not
overtighten (see figure 6). Remove the key and store it in a secure area with these instructions and the spanner
wrench.
Troubleshooting
Symptom/problem: Outside knob when turned always retracts latch without depressing any buttons.
Cause: Lock is in zero combination.
Solution: Follow the procedure for changing a combination except omit step 3 (do not enter the existing
combination).

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)