A door closer is a spring-loaded hydraulic device that closes a door automatically after being opened manually. often used in offices and commercial buildings.
The most common kind of door closer is the surface mounted door closer, so called because it is mounted to the surface of the door or header. Another type is the concealed overhead door closer which is mounted inside the header above the door.
High usage and changes in wind-loading are factors that may affect the performance of a door closer.
A malfunctioning or incorrectly adjusted door closer could present itself as a door slamming shut, or, not closing and locking securely. These conditions create safety and /or security risks and may also damage the door and associated fixings and fittings.