S&G 6120 Electronic Safe Lock Programming

Change master and user codes, set time delay, and manage access on the Sargent & Greenleaf 6120 electronic safe lock.

S&G 6120

⚠️ CAUTION — Read Before Changing Your Safe Combination

Always open the safe first and keep the door open while changing your combination. Test the new code at least 3 times with the door open before closing it. If you get locked out, drilling alone starts at $450+ depending on the safe's TL rating — and that doesn't include the repair and lock replacement, which adds another $250–$500 depending on the brand. A non-TL rated safe lockout can easily run $800 or more total for drilling, repair, and a new lock. Don't risk it.
Watch out for spring-loaded bolts. Many safes have spring-loaded locking bolts that automatically extend when the door swings shut. Before you start, open the safe door and put the lock in the locked position to retract the bolts. Look for a bolt release button on the inside edge of the door — it may be on the hinge side or the open side, depending on the model. Push it to lock the bolts in the retracted position so the door won't accidentally lock shut on you while you work.
If your lock is acting up randomly — beeping erratically, not responding consistently, or rejecting known-good codes — have it serviced or replaced immediately. A safe lock that fails completely is far more expensive to deal with than a planned repair. Don't wait until you're locked out of your valuables.

About the S&G 6120 Electronic Safe Lock

The Sargent & Greenleaf Model 6120 is a motorized electronic combination lock widely used on commercial and home safes. It features one Master Code and up to 8 User Codes, a programmable time delay (0-9 minutes), and EMP-resistant construction. The 6120 is a direct retrofit for S&G mechanical dial locks.

Model	S&G 6120
Factory Master Code	1-2-3-4-5-6
Code Length	6 digits
Max User Codes	8
Time Delay	0-9 minutes (programmable)
Power	Two 9V alkaline batteries (Duracell recommended)

Open the Lock

Basic Operation

Enter your 6-digit code followed by #.
The lock bolt retracts for 6 seconds.
Within those 6 seconds, turn the safe handle to the open position.

⚠️ Do NOT put pressure on the safe handle until AFTER entering the complete code and pressing #.

Change the Master Code

Steps to Change the Master Code

With the safe door OPEN, press 7 4 * (which spells "SG*").
Enter the existing 6-digit Master Code.
Press #. The lock chirps 5 times.
Press 1 *.
Enter the new 6-digit Master Code.
Press #.
Enter the new Master Code again.
Press #.

74* → [old MC] → # → 1* → [new MC] → # → [new MC] → #

✅ Success: 3 distinct chirps confirm the new code.

❌ Failure: A long continuous tone (brap) means an error occurred. The old code is still valid — start over.

⚠️ ALWAYS keep the safe door open when making programming changes. Test the new code 3 times before closing the door.

Add/Change a User Code

Steps to Add or Change a User Code

Press 7 4 *.
Enter the 6-digit Master Code.
Press #. Lock chirps 5 times.
Press the user position number (2 through 9), then *.
Enter the new 6-digit User Code.
Press #.
Enter the new User Code again.
Press #.

74* → [MC] → # → [2-9]* → [new UC] → # → [new UC] → #

✅ Success: 3 distinct chirps.

Delete a User Code

Steps to Delete a User Code

Press 7 4 *.
Enter the 6-digit Master Code.
Press #. Lock chirps 5 times.
Press the user position number (2-9), then * #.

74* → [MC] → # → [2-9]* → #

Set Time Delay

Enable or Change Time Delay (0-9 minutes)

Press 7 4 *.
Enter the 6-digit Master Code.
Press #. Lock chirps 5 times.
Press * *.
Enter the desired delay (single digit: 0 for off, 1-9 for minutes).
Press #.

⚠️ When time delay is active: enter your code → lock chirps 3 times → wait for the delay period → lock chirps 10 times → re-enter your code within 2 minutes to open.

Low Battery Warning

If the batteries are low, you will hear 20 consecutive beeps after pressing the # key on a valid code entry. The lock will still open, but replace batteries immediately. The lock uses two 9V alkaline batteries (Duracell or Energizer). Your codes are NOT lost during battery changes.

Wrong Code Lockout

After 4 consecutive incorrect codes, the lock enters a lockout period of 5 minutes. Do not press any buttons during this time — pressing buttons resets the lockout timer.

Troubleshooting

Beeps but won't open: Make sure you're pressing # after the code. Do not put pressure on the handle before entering the code. Replace batteries if low.
Long tone on code change: You made an error in the programming sequence. The old code is preserved — start over.
Lost Master Code: Contact S&G or your safe manufacturer. A Management Reset Code (MRC) may be available for your lock. This requires the safe to be drilled in some cases.
Lock clicks but door won't open: Move the handle to the fully locked position, then re-enter your code. The bolt work may be binding.

Manufacturer Documents

📄 Official Sargent & Greenleaf Support & Manuals

Frequently Asked Questions

What is the factory default code on an S&G 6120?

The factory default Master Code on the S&G 6120 is 1-2-3-4-5-6. You should change this immediately after installation. All programming sequences begin with 74* (which spells "SG*" on the keypad).

Will I lose my safe combination if the batteries die?

No. The S&G 6120 stores all codes in non-volatile memory that persists without power. Your codes will survive battery changes. Simply replace the two 9V alkaline batteries and your existing codes will still work.

How do I know if the batteries are low on my S&G 6120?

When batteries are low, you'll hear 20 consecutive beeps after entering a valid code and pressing #. The lock will still open, but you should replace both 9V batteries immediately. S&G recommends Duracell alkaline batteries.

What happens if I enter the wrong code too many times?

After 4 consecutive incorrect codes, the S&G 6120 enters a 5-minute lockout period. Do not press any buttons during this time — pressing keys resets the lockout timer. Wait the full 5 minutes, then try again with the correct code.

Need More Help?

If these instructions didn't solve your issue, contact the manufacturer directly or call your local locksmith:

📞 Sargent & Greenleaf Support 1-800-826-7652 Mon-Fri 8am-5pm ET

🔧 Key-En-Lock Locksmith (321) 224-5625 Brevard County, FL · Available 24/7

Can't reach the manufacturer? Our licensed safe technicians service all S&G models throughout Brevard County.