I can't lock my safe. The door handle won't go into the horizontal position even when you depress the keylock. Any other suggestions?

SSounds like the mechanism is rusty. Spray some wd40 oon the rod and levers that go in the door of the safe and on the pivots of the handle.

Lift the door handle as if you were opening it

Hold the handle & use a round phillips to hook
& rotate the white door latch to the open position

To close and lock

You can relock the safe in two ways. With the door

closed, depress the key lock (if equipped) with your

finger, or spin the combination dial one full turn.

For greatest security, do both. (Make sure the door
handle is in the horizontal position.) There is a link to the manual at the bottom of this page...
http://www.sentrysafe.com/Products/380/SW3750_Electronic_FIRE-SAFE_

To avoid damaging the mechanism, you must remove the cover of the dishwasher and with a screwdriver blade can unlock the door from inside.

you have 2 options or a) call locksmith b) follow the steps mentioned.
Instructions

1. • 1 Unwind the metal coat hanger so it's straight. Bend the end of the hanger so the tip resembles a hook.
     
   • 2 Slide the hooked end of the hanger between the window and the door frame right in front of the side of the door handle that is closest to the side mirror. Push the hanger down 1 1/2 feet and make sure the hook is facing you.
     
   • 
     
   • 3 Pull up and down on the coat hanger until the hook grabs the metal lock arm. The door lock handle will start to move once the hook has grabbed it. Pull up on the coat hanger until the door lock releases, then open the door.
     
   GOD BLESS YOU
   

SOUND LIKE IGNITION SWITCH KEYLOCK CYLINDER BROKEN. IN WHICH YOU CANT GET CAR OUT OF PARK.THE KEY LOCK CYLINDER BY TURNING THE KEY.IT MOVES A GEAR AND RACK ASSEMBLY THAT IN TURN MOVES THE IGNITION SWITCH ACTUATOR ROD AND PLUNGER TO VARIOUS POSITIONS REQUIRED FOR PERFORMING IGNITION SWITCH FUNCTIONS. IF KEYLOCK BROKEN YOU WONT BEABLE TO TURN IGNITION KEY OR GET CAR OUT OF PARK.

REMOVE IGNITION SWITCH TORX HEAD MOUNTING SCREWS DEPRESS THE IGNITION SWITCH RETAINING TABS THEN DETACH THE SWITCH FROM THE STEERING WHEEL. BEFORE INSTALLING THE IGNITION SWITCH MAKE SURE THAT THE KEY IS IN THE ON POSITION AND THE ACTUATOR SHAFT IN THE KEY LOCK CYLINDER HOUSING IS IN THE ON POSITION. ALSO MAKE SURE SQUARE RECEPTACLE IN THE IGNITION SWITCH IS IN THE ON POSITION.THEN INSTALL THE IGNITION SWITCH. MAKE SURE THAT THE RETAINING TABS SNAP IN TO PLACE. TO REMOVE KEYLOCK CYLINDER.PUT THE KEY LOCK CYLINDER IN THE ON POSITION, DEPRESS THE KEY LOCK CYLINDER

Locksmiths agree
1. Remove and discard the screw (if
equipped) at the base of the lock case.
2. Turn the electronic lock case to the
right (clockwise), from 12 o’clock to
2 o’clock, and remove.
• Insert 4 new AA batteries (not included) to power
this lock.
• Replace the electronic lock case and turn to the
left (to 12 o’clock) to reassemble.
NOTE: The yellow LED will light when the batteries
need to be replaced.
3. Turn the key (if your safe is equipped with a key
lock) to the right so the lock cylinder pops out.
4. Enter the factory code. When the green light appears, you
have four seconds to turn the handle down to
open. Try this several times before proceeding to
the next step.
To unlock safe:
Enter the 5-digit factory code, a pre-programmed
user code, or a pre-programmed user pin
programming instructions. When the
green LED lights you have 4 seconds to turn the
handle and open the safe.
To lock safe:
Close the door and return the handle to the
horizontal position. For greatest security, depress
the key lock (if equipped) with your finger.

This is locked in the open position.

You will need to go through the opening procedure to open the mechanism. You will then be able to close the door before locking it again securely.

I have a different model but I had the same problem. Called customer service and they had me push up on the handle and enter the code. That didn't work but then they had me tap the safe with a rubber mallet 5 times above the panel and 5 times to the right of the panel. That worked for me. Hope one of those works.