Can I replace a euro cylinder myself?

A cylinder may be replaceable by removing its retaining screw, but the correct internal and external dimensions, cam and door furniture still need to be identified. If you want a locksmith to supply and fit it, share the measurements or arrange an inspection so compatible-product availability and whether another visit is needed can be confirmed.

What size euro cylinder do I need?

The size depends on your specific door. You need to measure from the centre of the fixing screw hole to each end of the cylinder. Most residential doors in Coventry use cylinders between 70mm and 100mm total length, but the split between inside and outside measurements varies. Call 024 7522 4730 and I will measure it as part of the job.

Should I get a thumbturn or double cylinder?

For most front doors, I recommend a thumbturn cylinder because it allows you to exit quickly without a key in an emergency such as a fire. The exception is if your door has a letterbox or glass panel near the lock, where someone could reach through and turn the thumbturn. In that case a double cylinder or a letterbox restrictor is a better option.

How long does it take to replace a euro cylinder?

Timing depends on correct cylinder sizing, surrounding furniture, access, door alignment and whether the multipoint mechanism also has a fault. The replacement and keys are tested, and any additional mechanism work should be explained and priced first.

Euro Cylinder Locks: Types, Sizes and How to Measure

Learn how euro-profile cylinders work, how to measure an installed cylinder and which fit, function and certification checks matter before replacement.

What Is a Euro Cylinder Lock?

A euro cylinder is the removable lock barrel that sits inside a uPVC or composite door's multipoint locking mechanism. It's the part you put your key into. When you turn the key, it rotates a small metal cam that engages the multipoint lock — shooting bolts into the top, bottom, and side of the door frame.

Euro cylinders are widely used with multipoint mechanisms on uPVC and composite doors, but the cylinder and complete doorset still need checking before a replacement is chosen.

Types of Euro Cylinder

There are three main types, and knowing which one you have matters when it comes to replacement.

Single Euro Cylinder

A single euro cylinder has a keyhole on one side only. The other side is blank. These are typically used on doors where you don't need key access from both sides — garage doors, some back doors, and certain commercial applications. They're less common on front doors.

Double Euro Cylinder

A double euro cylinder has a keyhole on both sides — inside and outside. This is the standard type fitted to most uPVC and composite front doors in the UK. You need a key to lock and unlock from either side.

The downside: key-operated escape can create a safety issue if the key is unavailable. The appropriate arrangement depends on the door, glazing and letterbox position, occupancy, escape plan and any fire-safety duties; assess those before a lock change.

Thumbturn Euro Cylinder

A thumbturn cylinder has a keyhole on the outside and a thumbturn knob on the inside. You lock and unlock from inside by turning the knob, without a key. That can support keyless escape, but suitability depends on the complete entrance and applicable fire-safety requirements.

If a letterbox or breakable panel is close enough to allow reach-through access, the thumbturn position needs assessing as part of the complete entrance. Do not switch to a key-operated internal exit without considering escape and any applicable fire-safety duties.

How to Measure a Euro Cylinder

Getting the right size cylinder is critical. Too short and the lock won't engage properly. Too long and the cylinder will protrude from the door, making it easier to snap.

Here's how to measure yours step by step:

Remove the existing cylinder. Open the door, find the screw on the edge of the door (on the faceplate of the multipoint lock, roughly level with the cylinder). Undo that screw completely.

Turn the key slightly — about 10-15 degrees — so the cam retracts, then pull the cylinder out from either side.

Measure from the screw hole to each end. This is the critical measurement. You'll get two numbers — for example, 40mm outside and 45mm inside. That makes it a 40/45 cylinder (total length 85mm).

Note down both measurements. The outside measurement (from screw hole to the exterior end) and the inside measurement (from screw hole to the interior end) can be different.

Important: measure from the centre of the screw hole to each end. And measure the actual cylinder, not the key.

If you're not confident measuring it yourself, call me on 024 7522 4730 and I'll measure it as part of the job, then confirm the suitable product and availability before fitting.

Common Sizes in Coventry

Euro cylinders are sold in multiple internal and external dimensions. The exact size depends on the installed door profile, lock case, protective furniture and required projection, so measure the individual cylinder and complete doorset rather than assigning a size from a Coventry postcode, housing age or manufacturer name.

Major Euro Cylinder Brands

Certification and features differ by exact euro-cylinder model. These are examples of brands a customer may encounter; verify the current model rather than treating the brand name as evidence:

Yale

Yale sells several euro-cylinder ranges. Product names and certifications can change, so check the exact current model in the relevant certification catalogue instead of relying on the brand name alone.

ERA

ERA also sells several cylinder ranges. Compare the exact model's independent certification, dimensions and compatibility with the complete doorset before comparing price.

Avocet ABS

Avocet ABS is another cylinder range customers may encounter. Certification and warranty terms are model-specific and can change, so verify the exact current model and its compatibility. I explain the comparison process in my anti-snap locks comparison.

Ultion

Ultion offers independently certified cylinder models, but certification, product versions and manufacturer guarantees can change. Verify the exact model in the current certification register and read the current guarantee terms rather than relying on a brand-level promise.

Compare models, not just brands

Certification applies to a particular product or compatible combination, not every item sold under a brand. Check the exact certificate, size, protective furniture, guarantee terms and total fitted quote.

When to Replace Your Euro Cylinder

You should consider a lock change or upgrade if:

Your cylinder is more than 10 years old

You've moved into a new property and don't know who has keys

Your key is stiff or difficult to turn

The cylinder has no anti-snap protection (see my guide on lock snapping)

You've had a break-in or attempted break-in

Your written insurance policy specifies a lock standard that the current product does not meet

Euro-cylinder work is priced against the exact size, certification, door furniture and fitting scope. Check the current prices page, then call 024 7522 4730 with the door details for a specific quote.

A Note on Quality

Price or appearance alone does not establish a cylinder's performance. Check the exact independent certification, correct size and complete door-and-frame condition. A certified cylinder can improve resistance to tested attacks, but no cylinder guarantees that forced entry cannot occur.

Euro Cylinder Locks Explained: Sizes, Types, and How to Measure Yours