Our locksmith was called to a home in Arnos Grove as a customer was unable to open a wooden door with their keys. The door had dropped slightly and warped partly due to the change in temperature recently. Our locksmith was able to open the door fairly quickly then he adjusted the keep so it was inline with the lock and easier to open.
Quite often locks fitted to wooden doors can become stiffer and increasingly harder to use as the weather changes. If you notice this happening to your locks then it is a good time to check if the lock is lining up correctly before it gets any worse.