In this guide
First, stop if the key is resisting
Avoid twisting harder, using pliers or repeatedly trying a visibly damaged key. If it is bending, cracked or partly broken, leave it alone and explain that when you ask for help. If you are already safely inside, keep another authorised way out available while the problem is assessed.
Check that you have the intended key for this door. Similar-looking household keys are easy to mix up. If you have a known working spare that is undamaged, note whether it behaves differently without forcing either key.
Describe the symptom precisely
The point at which operation stops is useful information. The table below suggests what to record; it cannot diagnose the fault from a distance.
Scroll across the table to see every column. →
| What happens? | What to note | What to explain |
|---|---|---|
| Key will not enter fully | Correct key? Visible damage? Anything unusual at the opening? | When it last worked and whether a spare behaves the same |
| Key enters but will not turn | Does it stop immediately or part-way? Has the door been catching? | Whether the issue is new, intermittent or getting worse |
| Key turns but door stays closed | Does the handle move normally? Is the door sticking? | What moves and what remains stuck |
| Operation differs with door open | Only observe if the door is already open and you know normal operation | Whether closing the door changes the symptom |
Key will not enter fully
What happens?
- What to note
- Correct key? Visible damage? Anything unusual at the opening?
- What to explain
- When it last worked and whether a spare behaves the same
Key enters but will not turn
What happens?
- What to note
- Does it stop immediately or part-way? Has the door been catching?
- What to explain
- Whether the issue is new, intermittent or getting worse
Key turns but door stays closed
What happens?
- What to note
- Does the handle move normally? Is the door sticking?
- What to explain
- What moves and what remains stuck
Operation differs with door open
What happens?
- What to note
- Only observe if the door is already open and you know normal operation
- What to explain
- Whether closing the door changes the symptom
Look at the door as well as the lock
A lock operates within a larger assembly. The latch and bolt need to meet the relevant openings in the frame. Changes in the door position, loose or worn hinges and misalignment can affect that relationship.
Notice whether the door rubs, needs lifting or has recently become harder to close. Do not loosen hardware or adjust the strike plate simply to test an assumption. Record what happens during normal use so the assessment covers the door and frame as well as the cylinder.
Check the care instructions before adding products
There is no single maintenance product suitable for every lock. Check the manufacturer’s instructions for the exact model before introducing a lubricant or cleaner. If you cannot identify the hardware, ask rather than mixing products or spraying household cleaner into the keyway.
Wiping an exterior surface is different from servicing internal components. Do not push objects into the cylinder to investigate resistance. Tell the person assessing the lock about any product already applied, as well as any previous repairs.
Decide what kind of help you need
If you cannot get inside, explain the access problem when arranging lockout assistance. If the door is accessible but unreliable, describe that instead. The work should address the cause rather than assume that changing a key will fix every symptom.
For example, rekeying changes key access on suitable hardware. It is not a general repair for door alignment. Where parts are damaged or unsuitable, replacement options may need discussing after assessment.
Common questions
Stop if it resists or the key is deforming. Repeated force is not a useful diagnostic test.
The symptom alone cannot establish that. Describe any visible damage and seek assessment without assuming the cause.
A photo can help identify hardware and visible issues, but it cannot show every internal fault or how the door behaves in use.
Describe what the key does. Include your suburb and where operation stops.