Planned replacement rather than emergency lockouts
A scheduled appointment allows time to identify the lock, consider suitable replacement parts and understand any related door problem. This may be relevant when keys have changed hands, hardware has worn or an existing lock no longer operates smoothly. Explain whether the door remains usable and whether it can be opened normally.
This page does not offer emergency lockouts, forced entry or an immediate response to a property that cannot be secured. If you are locked out or need urgent security assistance, contact an appropriate emergency locksmith. Do not force the key or dismantle a closed door mechanism in an attempt to prepare for a routine booking.
Euro cylinders and compatible dimensions
Euro cylinders appear in many external door arrangements, but they are not interchangeable solely because their profiles look alike. The internal and external lengths, handle arrangement and required operation all need checking. A cylinder that projects excessively beyond the door furniture or prevents the handle from working properly is not an acceptable match.
Discuss whether the current cylinder uses keys on both sides or a thumbturn inside, and identify any requirements affecting escape or access. Product choice should also take account of your insurer’s stated conditions where relevant. Check the actual product specification against those conditions rather than assuming every replacement cylinder meets the same requirements.
Mortice locks and the condition of the door
A mortice lock sits within a pocket cut into the door, with its keep fitted to the frame. Replacement depends on the case size, backset, fixing positions and relationship with the existing handles or keyholes. Similar-looking locks can have different dimensions, making identification important before a replacement is purchased.
Loose timber, split edges or a moving frame can affect how the new lock is supported. A door that catches may need adjustment rather than a different lock alone. For associated joinery, see internal doors; changing an internal latch or handle should also be distinguished from replacing an external security lock.
uPVC mechanisms need their own assessment
On a uPVC door, the cylinder is only one part of the locking arrangement. The gearbox, handle spindle and multipoint strip may also be involved when the handle feels stiff or locking points fail to engage. Door alignment and the position of the keeps can create symptoms that resemble a failed mechanism.
Replacement mechanisms must match the relevant dimensions and operating arrangement. Manufacturer markings and clear photographs of accessible hardware can help, but specialist or unavailable components may limit what is suitable. Avoid buying a complete strip merely from its overall length, and do not assume that replacing the cylinder will correct every multipoint fault.
Agreeing the job and checking operation
Provide photographs of the door, handles, visible lock markings and the door edge where it opens normally. Mention sticking, dropped hinges, unusual key movement or previous adjustments. Any agreed replacement should include checking the operation with the door open and closed, without relying on excessive pressure to align the locking parts.
The property maintenance hub covers related small domestic tasks. If entrance work also involves a chime or video device, discuss that separately through doorbell installation. Electrical connections, door joinery and lock hardware have different requirements, so describe each item rather than treating them as one interchangeable repair.