BS Nightlatch won't unlock from outside

[dentonj]

I just fitted a high security ERA nightlatch (BS3621:2004) to my door to replace an old one. Followed instructions carefully and all in place and works fine - almost.

When I push the door closed and the small protruding point below the bolt is depressed as it touches the striker, the bolt protrudes further into the catch than it does normally - I presume this is the 'bolt throw'? Once this happens however, the lock cannot be unlocked using the key from outside. It's completely deadlocked - but it can be unlocked fine by using the handle on the inside.

If the door isn't closed, and the bolt throw isn't activated, the lock unlocks fine from the outside.

I am a bit stuck about what to do or what exactly the problem is - whether it's something gone wrong in fitting, or if I'm just not operating it properly, as I've never had a high security nightlatch before! But at the moment it means I can't use the lock as that's the only entrance/exit to my flat. Grateful for any opinions/suggestions before I call out a professional!

Thank you!

This is the lock: http://www.screwfix.com/p/era-bs-night-latch-polished-chrome-effect-60mm/37712

[mhole]

The tail piece on the cylinder is too long. Ensure it protrudes past the backplate by no more than 2 sections.

[mhole]

So, was this answer helpful? Did it resolve your problem?

If the answer is yes, a thank you costs nothing. If the answer is no, maybe we can help find an answer that will.

Anyone... Bueller?

[horsefeathers]

That's one of the reasons i don't offer to help out that much when a one time poster says..'i dont want to have to pay a locksmith, can you tell me what to do instead'. Helping a hobbyist or fellow locksmith is ok of course (to me).

in response to the actual question, i don't know if too long a tail is the cause as I never fit era BS nightlatches, prefer Yale. It probably is though, as i can see how it could interrupt the retraction of the boltwork.