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GJ Locksmiths

Help & Advice on Double Glazing Locks

Diagnosing problems with double glazed door locks -
  • Many enquiries concern locks on uPVC doors. Here are some suggestions to help you identify both some common problems and how best to describe your lock to us.
    Over the years manufacturers have sort to improve the level of security offered by each new generation of their locks. As a new model is introduced production of the older model is often immediately stopped and the remaining stock quickly runs down. Unfortunately this continuous development process means the older your lock the more unlikely it is that an identical replacement can be found. It is true to say that sometimes a replacement lock is such a close match that little work is required to install it. However, in most situation we need to alter the door to accommodate the replacement. Depending on the construction of the door, it's frame and the design of the new lock we may spend hours installing a replacement lock.

  • Some things to check

  • Is your double glazing still under guarantee? Worth checking as your installer may replace a complete lock at no cost to you.
  • If it's your door or lock causing a problem does it work properly with the door open? Is it only when it is shut that the problem becomes apparent?
  • How long has the problem existed and has it got progressively worse or just suddenly appeared?
  • Does the key operate smoothly in the cylinder? Again, try it with the door open.
  • Do the handles operate smoothly? We often have customers saying "help, the handles on my double glazed door will not push up". Once again, try them with the door open.
  • Make a note of what you find

Describing and identifying a double glazed door lock
  • Type of door - single hinged door, double patio doors/French windows, sliding patio doors
  • Is there any names or logos on the faceplate, the long strip running the full height of the door. Why make a lock and not put your mark on it? Some manufacturers don't bother.
  • The main central gearbox - Does it have a latch, latch & deadbolt or a latch and hookbolt
  • The Backset size. The distance from the leading edge of the lock to the centre of the cylinder - it can be 25mm, 28mm, 30mm, 35mm, 40mm, 45mm… 35mm is the most popular.
  • The 'PZ' size. The vertical distance between the centre of the keyhole and the centre of the handle. - common sizes are 83mm and 92mm. Are your handles offset with 92mm/62mm centres. Thats where the external handle is lower than the internal one.
  • Your Handles - lever/lever, lever/fixed pad, offset spindles. What colour - gold, polished brass, satin silver or pol. chrome plated. Do they need replacing?
  • Auxillary boltwork - do you have pins or hooks - going up, down or up and down, are there any anti lift pins.
    Any small rollers - are they plain round, mushroom or flat sliders.
    Any additional shoot bolts on the top and bottom of your door? (this is common on pairs of patio doors/French windows)
  • The more of the above details you can provide the easier it will be for us to identify your lock

Some general suggestions to prolong the life of your locks
  • Simple maintenance - oil the lock regularly.
  • How to lubricate a double glazed door lock - Try to spray some lubricant into all moving parts of the lock and down the inside of the long strip. To oil the long ancillary lock strip, start at the top and spray around all moving parts. Do this whilst moving handle up and down. Be careful of excess oil dripping from bottom of strip onto your carpet or patio. An important area is the center section, where the latch and deadbolt operate, normally beside the handles. The easiest way to oil this is to push the spring latch back into the strip with your finger and spray into the small holes exposed at the top and bottom of the latch. A great help here is the small plastic tube often provided free with a new spray can. A good trick to advoid loosing the plastic tube is to cut it down short enough, perhaps only 10 to 20mm, so that it can be left inserted in the nozzle whilst being protected when the cap is replaced. Powdered graphite is better for the key hole in the cylinder. Certain types of oil might clog it up. What, you don't have any powdered graphite? Easy. Fold a small piece of paper in half, producing a crease it down the middle, then open it out. Take a soft pencil and scrape the point with the edge of a knife so the powder falls onto your paper. The powder, being black, leaves marks that are difficult to remove without a good scrubb. So be careful. Lift the paper so powder collects in the crease and blow it very carefully into the key hole of the cylinder on both sides of door. Push the key in and out a few times and you should feel the difference.
  • If you encounter problems it is often cheaper to address the cause early, as that might lengthen the useful life of your lock. Not only that, it can make life soo much easier for you when operating the lock.

Replacing a lock
  • So we've identified the model and now the really hard part starts. Locating one in stock somewhere.
    Even when we have all the correct information we can still have problems identifying certain locks.
  • Bear in mind how much work is required in obtaining a replacement. There is a wide range of prices and thats before delivery and installation costs are added. It may seem expensive but it will still be much cheaper than a new door.
  • Our van stock includes replacements for some of the common locks.

  • We are happy to explain further any of the above.
Please telephone 07774 866333 or email us at info@g-j-locksmiths.co.uk

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