door lock problems

Key not turning in lock – Key won’t fit in lock?

key wont turn in lock. key wont fit in lock.

On a daily basis most locksmiths will get calls from customers complaining of different lock problems they, such as ‘key not turning in lock’ or their ‘key won’t go into the lock’. Some issues can be fixed easily by the householder. However, some issues are a little more complex, and may need the attention of a professional locksmith.

Listed below are some of the most common complaints regarding keys not turning in locks, and keys not fitting in locks.

Key won’t turn in UPVC / multi point door lock

Multi point locking doors operate by multiple locks coming out of the door when the handle is lifted. These locks then insert into the door frame, and lock the door in place.

These are the doors of choice nowadays for most homeowners and builders alike. This is due to their high security features, as well as being aesthetically pleasing to the eye.

When the key is suddenly not working in lock, its is usually down to 2 reasons. Either a broken barrel (Euro lock) or a broken bit metal within the door mechanism gearbox, both scenarios will make the door lock hard to turn key.

Broken barrel

If the Upvc door key won’t turn all the way, it could be the cam in the middle of the lock that has detached. Therefor preventing the lock from being turned open. Sometimes if the cam has detached fully from the lock, the key turns but door wont open. Unfortunately, when this happens there is no simple way for the person to get the lock out the door to swap it over. This is because to extract a euro lock from a multi point locking door you must take out the screw in the side of the door, put a key in the lock and turn whilst pushing the lock out the door. However because the key will not turn in the lock, this makes a conventional extraction impossible.

A locksmith would tackle this type of job by taking the handles of the multi point locking door to expose more of the lock barrel. They would then place an eurolock snapper over the barrel and snap the barrel in half. Once this is done the broken barrel can be picked out the door and a new one can be fitted.

Broken gearbox

If it is not the barrel that is broken, and in fact it is the gearbox has broken, that will need replaced for the door to function properly again.

It is possible for a householder to do this type of job themselves. However, they would need to snap the barrel out as described above. Also most parts for multi point locking doors are not readily available to the public. Not to mention the householder would need the tools, and a little bit of knowledge of how these mechanisms come apart, and get put back together again.

For a locksmith who specialises in UPVC door lock repairs this type of job is relatively straight forward, and would be done hundreds of times a year. Most locksmiths carry the most popular gearboxes in their van. That way they can take off a broken gearbox, and replace it with a new one on the same day. This means the customer can have a secure property, and the locksmith doesn’t need to make a return visit.

Key won’t turn in Yale lock (nightlatch)

Broken lock body

One of the most common locks on a wooden door is a nightlatch. Although some people refer to them as Yale locks, this is because the vast majority of Nightlatch locks have been made by the lock manufacturer Yale.

When a key won’t turn in a nightlatch lock it could be that that the lock mechanism is broken inside, and is preventing the key from turning. In this scenario the lock body can simply be screwed off the door, and a like for like replacement can be placed on to the existing holes in the door.

If however the broken lock body on the door is not available in the shops, the services of a joiner or locksmith may be required to install a new lock. This is because very few locks come in the exact same shape and size as each other. Usually new drill holes and wood will need chiselled away. This is to allow the new shaped lock body to fit comfortably on the door.

Seized or vandalised pins in the lock cylinder

Within almost every lock cylinder (part where the key goes in) there are a series of serrated pins which move up and down when a key is entered and extracted from the lock. These pins are cut to specific heights which will only allow the key that is matched to those pins, to open the lock.

When someone is unable to put their key into the keyhole is is usually down to 2 reason.

The first reason being the pins within the lock no longer have any lubrication, and are unable to move up and down freely to allow the key to lift them up. Usually this is a gradual process where opening the lock and extracting the key will become increasingly fiddly. If caught early enough the damage can usually be reversed. Simply spraying some lubricating oil into the keyhole will be enough to coat the pins and enable them to move up and down freely again. If the cylinder is allowed to go too long without lubrication, the pins can eventually fuse together. When this happens a new cylinder will be required in the nightlatch.

The second reason someone would find a Key hard to get in lock is due to vandalism. If a lock has had glue sprayed into it, or someone has put a foreign object in the keyhole. The pins inside the lock will no longer lift to the desired height, to allow the key to turn. When this has happened the lock will need to be extracted and a new one fitted. If the door is open the customer could buy a new cylinder from a hardware store and swap the damaged cylinder for a new one.

If The door is locked when the customer realises the lock is damaged, the may need to call a locksmith to drill open the lock and replace with a new one. Most Emergency locksmiths with be able to open and replace the cylinder without having to replace the whole lock.

Key won’t turn in mortice lock

Mortice locks are the type of locks that are fitted into most older type wooden doors. They consist of a lock body with some levers inside which lift up, when a key is put in the hole and turned. The key Grabs onto a bolt when it passes these levers, and slides the bolt open and closed – depending on which way you turn the key. The main issues people have with these locks are a faulty keyhole curtain (bolt thrower), faulty levers, and damaged keys

mortice lock curtainbroken curtain / Bolt thrower

When a mortice key cannot be entered into the keyhole, this is usually because the curtain (metal flap onside keyhole) has spun out of position, and is blocking the entrance to the keyhole. This usually happens when the curtain begins to lose its spring through time. The householder can simply get a screwdriver, insert it into the keyhole and turn the curtain back into its normal position. They will know its in position because the will be able to look straight through the keyhole – meaning a key can now be entered. This curtain moving out of position could just be a one off freak occurrence, However if it happens again a local lock fitting service is probably the best the route to go down.

Faulty levers within the lock

When the mortice key can be entered into the keyhole, but the key will not turn, that is a sign there is a problem with the levers in the lock, or the key has a piece missing from it.

Problems with lock levers can be caused by them fusing together, due to lack of lubrication, or if  levers have detached from the post that holds them in place. If any of these issues happen when the door is locked it will be a job for a locksmith or someone with a knowledge of the inner workings of a lock. The lock will need to be drilled open, and in some cases the lock levers manually extracted through the drill hole. Although this is less than ideal, locksmiths do carry special key hole covers which are designed to cover up where the drill hole is on the door.

If the deadbolt won’t turn in the lock, or the key won’t turn fully in the lock, it could also be down to a broken key. If one of the teeth has fallen off the key, it will no longer lift all the levers to the desired height. This can be a simple fix though. If the home owner has another fully intact key, they can take it to a key cutting shop and have a replica key cut. Once this is done the lock will Fully open and close again like normal.


Although there are many other reasons why a key won’t turn in the lock, The scenarios detailed above are the most common encountered by locksmiths on a daily basis. For any further advice have a look at some other lock related articles have a look at our locksmith blog page.