Front doors that can't open from the inside

cookie365

Hello, can anyone who knows about door locks explain this to me?

An elderly neighbour has a front door that has a Yale type lock plus a regular mortice lock.

The Yale lock has no keyhole on the inside. On the inside is an oridinary little rocker thing that fixes the bolt in position, either out or in if you turn the handle then press it. Nothing unusual there.

He unlocks the door from the outside by turning the key 90 degrees clockwise (the lock is on the right side of the door from the outside).

If he turns the key 360 degrees anti clockwise a special extra locking mechanism kicks in, which I don't quite understand.

Today, he discovered he couldn't open the door from the inside. His lifestyle is a bit shall we say haphazard meaning he couldn't get out through the backdoor. He had to call me, pass me the keys through the letterbox so I could open the door from the outside.

I assume that the last time he went inside he must have turned the key 90 degrees clockwise to unlock it, opened the door, then instead of turning it back 90 degrees anticlockwise and removing the key he must have somehow turned it back 450 degress anticlockwise to activate the double lock.

Is that right?

Apart from the embarassment of having to get somebody else to let him out of the house, what happens if there's a fire?

I guess it works like that to stop people slipping the latch with a piece of plastic, but as there's a mortice lock to provide extra security it seems like a dangerous risk to take.

What do people in the know think? Can he somehow turn off this double locking thing so he doesn't accidentally do it again, or will he have to buy a new lock?

Ectophile

It is a deadlock mechanism that you can get on Yale-type locks. If you put the key in and spin it around once in the "wrong" direction, it deadlocks the latch so it can't be pushed open using the credit card trick.

It shouldn't be possible to lock yourself in. With the lock deadlocked, it won't be possible to close the door. However, it would be possible to lock somebody else in - so these locks should never be used on communal front doors.

I did have such a lock malfunction on me once, and found I was stuck inside my flat. I ended up taking the window out of the door and reaching through with the keys to escape. I took the lock apart and put it back together again, and it never did it again. I still have no idea what caused it to lock.

cookie365

Thanks Ectophile. I'm not sure how he managed to trigger it when he opened the door from the outside.

I guess that short of him buying a new lock he's stuck with it, no way of disabling the deadlock?

Ectophile

I don't think there's any alternative but to buy a new lock.

cookie365

Thanks, it's really none of my business but I'll try to suggest to him that he ought to get a new lock.