An expert explains how to change a lock and secure your home

Step 3: Measure the size of your existing cylinder

To ensure your new lock fits correctly, you will need to measure the size of your existing cylinder. You can do this by measuring the length of each half, either side of the cam, to the centre of the cam. This will give you two measurements to work with, for example – 60mm and 40mm.

You’ll need to remember which measurement is for the external side of the cylinder and which one is for the internal side, as this affects the size of the cylinder you purchase. This is because the external side offers the protection against any attacks, so will provide the security for your door.

Step 4: Align the cam with the centre of the cylinder

Once you have purchased your new cylinder, you will then need to align the cam with the centre of the cylinder. You will need to insert the key and align the cam with the centre of the cylinder, and then place the lock into the door/handle. As you did in step 2, you may need to twist the key slightly to ensure the cylinder slots back into the lock.

Step 5: Secure your new cylinder in place

You will need to replace the cylinder fixing screw and screw this in place tightly to secure your new cylinder. You can check the cylinder is fitted correctly by lifting the handle and turning the key. If this all works correctly, your cylinder will be in good working order.

Lastly, you can then replace each side of the handle, fix back into place, and test the operation of the handle together with the lock to check it all works together correctly.

Tips for securing your home

Don’t opt for a ‘cheaper’/substandard lock: A door lock is essentially the first level of protection for your home, so it’s essential to provide the maximum level of security.

Make sure you measure the cylinder correctly: It’s essential to ensure that the two measurements (from each side of the cam) are the right way around. You need to know which is the external and which is the internal side, as the external side provides the protection against burglary attacks.

Fit the cylinder correctly: Another very common mistake, but an incorrectly fitted cylinder offers your home no protection – you may as well leave the door open!

Go for the help of a locksmith if needed: Having an incorrectly fitted lock could end up costing you thousands of pounds in stolen items if your home is broken into. So, it’s worth bringing in a locksmith if you’re unsure how to change your lock.

Create an effective master key system: Master keys – one key that opens every door in your home – are a great way to create a convenient security system, but it can mean that if your keys got into the wrong hands, every door to your property could be at risk. Avoid this mistake by being selective with the locks you want to be part of your system i.e. allowing the key to open the front door but not the patio doors.

Know when to replace a lock:

• When you first move into a new house, as previous owners (or their friends and family) may still have spare keys to your property
• If you have a low-security door lock (you should opt for a lock that has the ‘3-star’ seal of approval as this offers the highest level of protection)
• If your lock is rusty or looking worse for wear (a burglar can spot if the lock is weak)

£1 coin trick: Yale’s £1 coin trick can allow homeowners to see if their lock is protecting their home.

Homeowners should look at their lock cylinder, and, using a £1, see if this is protruding more than the depth of the coin. If so, then the lock could easily be compromised by criminals, and highlights that the cylinder needs replacing.

Experts at Yale would recommend updating your cylinder to one that has a TS007 3-star Kitemark, as this proves that the product meets the standards set out by the British Standards Institution.

Focus your home security on the front door: New statistics from Yale UK have shown that in the case of a domestic burglary, 23% of burglars gained access to a property through the front door, highlighting the importance of heightened front door security.

Your front door is often the first line of defence for your property, so investing in front door security, whether that be a maximum/3-star cylinder lock, or a security camera is an essential part of protecting your home.

Go for a high security cylinder: When selecting a front door lock, the experts at Yale would always recommend investing in the highest level of protection, which is a 3-star cylinder. This has the three stars clearly marked on the front, which means if any opportunists come to your front door, they will notice the stars and realise this has the highest level of protection – and yes, seasoned criminals will know this!

Choose a lock that has anti-snap properties: Lock snapping is one of the most common ways a burglar will use to break into a property, so Yale recommend ensuring that your chosen cylinder has an anti-snap guarantee, as this will provide significant protection for your home.

Ensure your cylinder meets the requirements made by your insurance company:
Insurance companies require a level of security on your locks, and most insurers will insist that your lock conforms to British Standard BS3621. Check with your insurer to make sure your locks meet the minimum requirement.

Choosing a lock from a well-known trusted brand: A lock from a trusted security brand will not only show opportunists that this has a secure level of protection, but most well-known brands undergo rigorous testing to protect against a range of attack methods.

Decide if you want a master lock system: A master lock is a convenient way of ensuring all the locks in your home operate through one key. A homeowner should decide if they require a master lock system (also known as keyed-alike) ahead of installing their new lock.