Quick answers and guides to the most common everyday questions from window and door manufacturers and fitters.

What is a Eurogroove?

A Eurogroove is an industry standard feature on most PVCu, aluminium and timber door and window profiles, where the locking devices are fitted.

A Eurogroove is the groove in the profile in which multipoint locks and espagnolettes are fitted. This is always 16mm for PVC, but can be 20mm in Timber.


How to fit a Patriot Plus Hinge

Tools required:

  • 5mm Hex Key
  • Door Jig (part number Jig-0036)
  • 4mm drill bit
  • Plastic Hammer

View the video for full details on fitting.

How do I adjust the Patriot Plus hinge post-installation?

Lateral and height adjustment:

Tools required:

  • 5mm Hex Key
  • Screwdriver

The lateral alignment of the Patriot Plus Hinge can be adjusted by +/-6mm

The height can be adjusted by +8mm


Compression Adjustment:

Tools required:

  • 4mm Hex Key

The compression of the Patriot Plus Hinge can be adjusted by +/- 1.5mm

What is PAS 24?

PAS 24 is an enhanced security performance test for door assembly requirements,  every component used within the door set tested must comply to the relevant British Standard for that component.

PAS 24 includes several security tests, such as:

  • Manual intervention
  • Mechanical loading
  • Hard and soft body impact

An example of the intensity of the testing, the mechanical loading tests subjects the door set to 4.5Kn of pressure, the equivalent of approximately 45 times the pressure used to tighten a car wheel nut.

How do I achieve TS 007 on my doors?

TS 007 is a security standard relating to the door handle and cylinder combination used on a door. To achieve TS 007 status, the combination used must total 3 stars.

A cylinder can achieve either 1 or 3 star classification, where as a door handle can only ever achieve 2 stars.

Therefore, it is possible to achieve 3 star accreditation by combining a 1 star cylinder with a 2 star door handle. Or, just using a 3 star cylinder alongside an unaccredited door handle. See our simple diagram below.

Achieving TS007 is vital in order to pass any door to PAS 24 or achieve Secured by Design.

What is anti-snap, anti-pick, anti-bump, anti-plug extraction and anti-drill?

Anti-Snap – the cylinder has a section or sections, often called a sacrificial cut, either side of the central lock mechanism that will come away if the cylinder was to be attacked from the outside, however leaving the remainder of the cylinder mechanism intact and locked.

Anti-Pick – the top half of the pin stack inside the cylinder are designed to include a mushroom shape or indent. Therefore, if something was used to pick the cylinder it would catch on the pins and prevent the cylinder from unlocking.

Anti-Bump – cylinders are designed to have more pins (generally 6) and a shallow pin stack. By doing this it means that if a bump key was knocked into the cylinder, the pins would not jump up meaning the cylinder could not be bumped.

Anti-Plug/Core Extraction – the cylinder has strengthened steel circlips that hold the cylinder in place so the core cannot be extracted from the cylinder.

Anti-Drill – the cylinder has plates and pins built in and this prevents the cylinder core being turned if the pin stack was attacked by a drill. It is designed to break the drill bit and protect the integrity of the cylinder to prevent entry.

What is the difference between restricted and open profile cylinders?

Restricted profile cylinders / key systems are non-duplicable, meaning it’s impossible to purchase blank keys in the market and create fraudulent keys. These cylinders provide a higher level of security.

On the other hand, open profile cylinders mean that any key cutter on the market can make replacement cuts and the cylinders can then be mastered from this. This can sometimes be a homeowner’s preference as it is easier to get additional keys cut.

What is BS EN1303?

BS EN 1303 is a British Standard relating to cylinders. It is broken down into 8 digits and ensures that the cylinders are tested to the highest standard. The 8 digits are; Category of Use, Durability, Test Door Mass, Fire Resistance, Safety, Corrosion and Temperature Resistance, Key Related Security and Attack Resistance.

Cylinders are graded based on this criteria.

How to replace a euro cylinder?

Step 1: Open the door and loosen the door handle fixing screws slightly, or remove them and the handles completely

Step 2: Unscrew and remove the cylinder fixing screw

Step 3: Put the key in the cylinder and slightly turn it until the cam tongue is aligned, once this is aligned you can pull the cylinder out, (generally the key will point to around 5 to or 5 past on a clock face)

Step 4: Replace with the new cylinder and then repeat the process in reverse order

When would I need a free movement cylinder?

A free movement cylinder allows a key to operate the cylinder even when there is already a key inserted in the other end. These cylinders are for use on emergency exit door lock kits such as the FUHR 870 and 871. This function ensures that when the panic bar or panic lever is pushed the cam will rotate freely and allow use at any time.

This type of cylinder is also recommended for use with the FUHR 881 Electromechanical Door Lock.

What types of door handle are there?

There are three popular types of door handle. Refer to our website or catalogue for the full range of brands, designs and colour options.


  • Levers on the inside and outside of the door.
  • Ideal for use with a lever operated multipoint door locking mechanism.


Lever/Moving Pad

  • Lever on the inside and a moving pad on the outside of the door.
  • Moving pads are usually used with split or dual spindle multipoint door locking mechanisms.


Lever/Fixed Pad

  • Lever on the inside and a fixed pad on the outside of the door.
  • Fixed pads are used with key wind up locks

Is it possible to use one key to open multiple doors?

Yes, this system is called keyed alike. It is where one key can open a group of keyed alike cylinders, so for example someone’s front door key could also unlock their patio doors and back door. All of the euro profile cylinders supplied by Carl F Groupco have the option to be supplied in this way.

You can also opt for a master key system, this is useful for buildings where different types of access are required, usually in hotels or where building management is required. This usually isn't recommended for standard domestic properties.

How to measure for a replacement euro cylinder

Step 1: Measure the overall length from the bottom part of the cylinder

Step 2: Measure from the centre screw hole to each end, these two measurements combined should be equal to the overall length


Step 1: Measure from the centre screw hole on the door lock to the face end of the cylinder on each side, these two measurements will be equal to the overall length

How do I measure the PZ centre and Backset on a door lock?


The backset is the dimension from the front of the faceplate to the centre of the handle spindle or cylinder hole.

The most popular backset sizes are 25mm, 30mm, 35mm and 45mm.

The backset dimension is the distance between A and B on the diagram.


PZ Centre

The "PZ" or "Centre" is the distance between the centre of the handle spindle and the centre of the round section of the cylinder. 

The PZ Centre dimension is the dimension between C and D on the diagram.

Multipoint locks can have one or two spindle holes (also known as followers) these type of locks will have two measurements, the most popular being 62mm / 92mm.

Most modern locks with one spindle are 92mm centre, however some older locks may be 70mm or 72mm.


How do I change the handing of a FUHR door bolt?

On most FUHR locks, to change the handing you remove the small grub screw on the side of the lock case adjacent to the latch plate with a 2mm allen key.

Remove the latch and turn in it 180º vertically, place it back into the opening and secure the grub screw back in place.

The FUHR 871 and FUHR 881 door locks are supplied handed, this cannot be changed, so please ensure you order the correct handing for the application.

How do I replace a FUHR Lockcase?

Step 1 Unscrew and remove the 3 screws as shown in the video

Step 2 Remove the lockcase

Step 3 Clip the replacement lockcase in place

Step 4 Replace the 3 screws


How do I adjust FUHR keeps/strikers?

Hook and Keep alignment:

The hook and keep should be aligned using the guideline on the hook plate. Ensure the hook engages correctly avoiding friction on which can result in damage to the hook, there should be a 2mm gap between the line on the hook plate and the flat of the hook as shown in the diagram.


Latch and hook adjustment:

Take care not to over adjust the hook keep as this can damage the keep - do not rotate through 360º.
A screwdriver and a 4mm allen key will be required when adjusting these plates.


Roller and mushroom adjustment:

Adjust eccentric compression of roller and mushroom keeps to ensure the optimum compression for the door.
Adjust the compression using a 4mm allen key.


What are the changes to Part F 2021 for trickle vents?

Approved Document F: 2021

Why are there new Part F regulations?

The Future Homes Standard 2021

  • Government led project: 31% reduction in CO2 by June 2022
  • Includes updates to Part L and Part F regulations
  • Currently applies to installations in England
  • For windows and doors, by 15th June 2022
    • U values reduce from 1.6 to 1.4
    • Expected goal of 0.8 by 2025

What products can I use to comply?

As windows now make homes more airtight, additional ventilation is required to circulate air in living spaces. Options include mechanical ventilation, extractor fans and trickle vents.

Trickle vents are by far the cheapest and most practical solution to achieve the regulations for both new build and replacement markets.

  • New trickle vents are being launched to offer increased equivalent area air flow.
  • Adjustments to slot heights may be needed to achieve the EQA requirements.
  • Carl F Groupco stock compliant vents from Glazpart, Greenwood, RW Simon and Yale.

What are the new regulations?

for dwellings regarding ventilation....

New build and extensions:

  • Habitable Rooms + Kitchens
    • 8000 EQA
    • 10,000 EQA (single story)
  • Non Habitable Rooms + Bathrooms
    • 4000 EQA
    • 5000 EQA (single story)
  • WC's + Utility Rooms
    • No defined EQA but ventilation is recommended to be provided.
  • Open Plan Living Room + Kitchen
    • If the dwelling has a kitchen and living room which are not separate rooms, at least three ventilators of the same area as for other habitable rooms should be provided in the open-plan space.

Replacement Market:

  • Replacing less than 30% of glazing
    • Replacement windows must provide at least the equivalent EQA as the old window.
    • If no ventilation was previously in place, the EQA standard for new build must be adhered to.
  • Replacing more than 30% of glazing
    • Follow the regulations as for new build and extensions when replacing more than 30% of the glazing products.


New reporting, compliance and certification required by installers from June 2022.

Always refer to the government regulations, download the full document here: https://www.gov.uk/government/publications/ventilation-approved-document-f



How does the FUHR autosafe 833 door lock operate?

On closing the door, the latch depresses.

A magnet which is built into the keep/striker engages the latch. 

The latch throws 20mm into the keep/striker and deadbolts.

The latch remains secure and locked until the the door is unlocked.

How can I ensure my FUHR 881 is working correctly?

Step 1 Remove the magnet from the frame

Step 2 Close the door until the tappets on the hinge side touch the contact plate (don't fully close the door)

Step 3 Place the magnet against the small circule within the magnet part of the door lock

Step 4 If the hook locking points extend, then the lock is working correctly.

What are the SmartSecure access control options?

The SmartSecure access control options available from Carl F Groupco are:

  • Finger print scanner
  • SmartTouch (which can be built into a lever handle)
  • Keypad
  • SmartConnect
What does a master key suite mean?

This cylinder key system is used where you need to provide different levels of access to different people within a building. For example, a system could allow for cleaning staff to be able to unlock all cylinders in an office, but only allow individuals to unlock their personal office door.

What are the main benefits of the Roto TSL espag?

Watch the video to explore the main benefits of the Roto TSL espagnolettes.

What are the security benefits of the TS008 letterplate?

The video illustrates the potential security threat that letter box fishing poses to homeowners. 

The Yale TS 008 letterplate conforms to PAS 24 and approved to Document Q and overcomes this issue.

The inner protective housing has a unique concealed hinge mechanism to prevent attack.

The inner flap has a positive stop feature for maximum protection from 'fishing'.

How do I pair Yale L1 Conexis with my smart phone?

You should only pair one smart phone with the lock. You will then be able to send mobile keys to other smart phones using the Yale lock app.

Download the app for iPhone or Android. Create an account and follow the onscreen instructions.

Create an account and 'Add a New Lock'. Follow the video guide on how to use.



What are your opening hours?

Our offices are open Monday - Thursday 8am - 5pm and Friday 8am - 4pm.

Do you fabricate or install doors?

No, we supply the door hardware including electromechanical door lock, associated components and access control to door fabricators. If you wish to purchase a door featuring any of the SmartSecure hardware, then please let us know and we can put you in touch with one of our recommended fabricators.

How do I place an order for tools from Carl F direct?

Orders can be placed through the Carl F direct ecommerce website with secure Barclays ePDQ payment.

Alternatively you can call our sales office on 01733 393330 to place and pay for your order over the phone.

If you hold a credit account with Carl F Groupco, you may also add Carl F direct items to your usual hardware orders.

How do I check the details of a product?

If you can't find the product information you require on our website, please get in touch by completing the enquiry form below and we'll confirm the details as soon as possible.

Please be aware that we are open Monday - Thursday 08:00 - 16:30 and Friday 08:00 - 16:00 and we're closed on Bank Holidays.

Queries sent outside of these hours will be dealt with when the office opens on the next working day.

Showing 0 of 0 Results

Load More

Can’t find the answer you’re looking for?

Submit Your Own Question

Request a Callback

Please tick the reCAPTCHA*

Please tick the reCAPTCHA*

Keep In Touch

Contact us for more information on our products, services, and support. Stay up to date with our latest hardware news and connect with our team on Twitter and LinkedIn.