As part of a Tenant's Tenancy agreement they are required to undertake minor repairs and maintenance to the property and this includes keeping door handles tight. In the event that they don't and they come loose or fall off they may be charged to repair the handle.
As a tenant you may consider tightening a loose handle as too big a task but in fact it is a simple task and will take no more than a few minutes. Of course you can call a contractor to do it but this will likely cost £80 upwards.
Below is a video and step by step guide which explains how to tighten a loose door handle.
Fix a Loose Faceplate With Exposed Mounting Screws
On many newer, less expensive locksets, the faceplate—the round plate that fits against the door surface itself—has two exposed screws that may loosen over time, causing the doorknob mechanism to wobble. When this occurs, it's an easy matter to simply tighten these screws to snug up the door again.
On lever-style handles, you can almost always access the mounting screws easily. With round doorknobs, though, you may need to remove the knob in order to make the faceplate mounting screws accessible to your screwdriver. The doorknob may be attached with a set screw (see above) or with a detent button or slot.
Tighten up the faceplate with a screwdriver. If the screws have detached completely from the mounting threads on the opposite side of the door, you may need to begin threading them by hand before using the screwdriver.
Fix a Loose Faceplate With Hidden Mounting Screws
On high-end newer locksets, the mounting screws holding the lockset mounting plate to the door may be hidden under an outer faceplate.
To get at these mounting screws, release the doorknob or lever by depressing a spring-loaded catch, known as a detent, and sliding the knob or handle off the spindle. There are three common ways to access and depress the concealed detent which secures the handle:
A small round hole: This type is found commonly on lever-style door handles. To depress the detent, use the end of a metal paperclip or the point of an awl, inserting it into the hole and pressing the detent down while twisting and removing the door handle shaft off the spindle.
A slotted hole: This type is usually found on round doorknob hardware sets. To depress the detent, insert a small flat-blade screwdriver through the slot to press and release the detent while twisting and removing the doorknob off the spindle.
A button: Button-style detents are often found on less expensive round doorknob hardware sets. They have a button that is near flush with the surface of the doorknob shaft. Depress the button using an awl or tip of a small flat blade screwdriver while twisting and removing the doorknob off the spindle.
Pry off the faceplate—a decorative trim plate that covers the lockset mounting ring. Sometimes this is a simple friction-fit ring that can be pried off the spindle; there may be a small notch in the plate designed for this purpose. With other styles, the faceplate is threaded and removed by unscrewing counterclockwise.
Tighten the long screws that secure the lockset's mounting ring to the door. These screws generally run all the way through the door and secure to the lockset mounting plate on the opposite side. Tighten them until snug.
Once the lockset is tight, reinstall the decorative faceplate and the doorknob.