We have a magnetic lock on the front door of our apartment building. From time to time it stops working - it just doesn't lock the door. It seems as it doesn't have power or is somehow turned off because the little light on the button for unlocking it from the inside is not lit. The box with the power suppply inside is locked and I think nobody from the building has a key for it (only the company which installed the door has a key). However, yesterday I found the door propped up with a small rock in order not to close. This was done by a dentist in the building so she doesn't have to click the button from her consulting room everytime a patient comes in.

Is there a possibiliy that she did something and turned the system off? Could it have broken because it had stayed open for hours?

The box with the power supply inside which can't be opened (I hope). This is the box with the power supply inside

The magnetic part of the lock. The green thing on the magnets is something sticky. I think it wasn't cleaned good enough when unboxing the lock. This is the magnetic part of the lock

The back part of the lock. Everything seems connected. This is the back part of the lock

  • you can easily open that box with very common tools...
    – dandavis
    Jul 26, 2018 at 17:39
  • Does anyone ever lubricate the sliding bolt? Has the building settled, changing angle between bot and hole? Jul 26, 2018 at 21:23

1 Answer 1


Magnetic locks are set up in one of two modes: 1) fail safe, or 2) fail secure. Sounds like yours is “fail safe”.

1) Fail safe mode allows the door to open when the electricity goes out. We use this mode in apartments, commercial buildings, etc.

2) Fail secure mode locks the door and prohibits access when he electricity goes out. We use this mode in jails, etc.

It appears you have a circuit breaker that is very sensitive or overloaded, which is causing the circuit to trip and making the magnetic lock go into “fail safe” mode...leaving the door unlocked and open.

One means of fixing your problem is to add a battery backup.

  • Thank you so much for the information! Could it have get broken because it stayed open? Sorry if it's a dumb question - I don't know much about electricity. Jul 26, 2018 at 11:46
  • Yes, it could cause the circuit to “trip”.
    – Lee Sam
    Jul 26, 2018 at 15:17

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