Why won't my French door lock — and why won't the handle lift?

Many French doors, hinged patio doors, and newer front doors do not use a single deadbolt. They use a multipoint lock: one handle and one key that drive a long steel bar inside the edge of the door. Lifting the handle pushes bolts or hooks out at the top, middle, and bottom at once. Turning the key then holds them there.

That design seals and secures the door well. It also means the lock only works when the whole door lines up with the frame at three points. When the handle will not lift, the key will not turn, or the handle suddenly goes loose, the lock is usually telling you about the door, not just the key. This guide covers home and business doors only.

First: do not force the handle

If the handle fights you on the way up, stop. Forcing it is the most common way a multipoint lock goes from an adjustment to a replacement. The handle drives a small gearbox inside the door, and leaning on it can strip the gears or snap the internal parts. Once that happens the handle often goes floppy, and the door may not lock, or may not open, at all.

If the door is stuck locked and you cannot get out through it, use another door. If it is your only way out, or the door is stuck open and you cannot secure the house overnight, call a locksmith rather than prying at it.

Common causes

• The door has moved. Seasonal swelling, settling, or a dropped hinge shifts the door a few millimeters, and the hooks or bolts no longer meet their keeps in the frame. This is the most common cause, and it often shows up when the weather changes.
• Worn or loose hinges. A door that sags on its hinges drops on the latch side, so the top bolt rides high and the bottom one jams.
• Keeps out of adjustment. The metal plates in the frame that catch the bolts are often adjustable. If they have been knocked or the screws have loosened, the bolts miss them.
• Compressed or swollen weatherstripping. Thick seals push the door away from the frame so the hooks cannot reach far enough to engage.
• A worn or broken gearbox. If the handle lifts with no resistance, feels loose or floppy, or the bolts do not move when you lift it, the gearbox inside the door is likely worn or broken. This is a part replacement, not an adjustment.
• A worn cylinder or key. If the handle lifts fine but the key is stiff or will not turn, the cylinder or the key may be worn, the same way it would be on any lock.

A quick test you can do

Open the door and, with it open, lift the handle. Watch the edge of the door. If the bolts or hooks move out smoothly and the handle lifts easily, the lock itself is working, and the problem is alignment between the door and the frame. Lower the handle again before you close the door.

If the handle will not lift, feels gritty, or lifts with no resistance while the bolts barely move even with the door open, the problem is inside the lock, and it is a locksmith job.

What a homeowner can safely do

• Push or pull the door firmly toward the frame while you lift the handle. If it locks easily that way, the door needs adjusting, but you have confirmed the lock works.
• Check the hinge screws on both the door and the frame side and tighten any that are loose. A loose top hinge is a frequent cause of a sagging door.
• Look at the keeps on the frame for scrape marks. Shiny marks above or below the opening show which way the bolts are missing.
• Clean the edge of the door and the keeps of grit, and put a light spray of a dry PTFE or silicone lubricant on the moving bolts and hooks. Avoid heavy oil, which collects dirt.
• On a pair of French doors, check that the fixed door's top and bottom bolts are fully engaged first. If the fixed door is loose, the active door cannot lock against it.

What to leave to a locksmith

Adjusting keeps, resetting hinges, and replacing a gearbox or cylinder are normal locksmith work. Multipoint locks come in many makes and lengths, and the replacement gearbox has to match the one in the door, so the locksmith usually measures it in person. Taking the gearbox out means removing the handles and the long strip on the edge of the door, and it is easy to damage a door or order the wrong part.

If the door frame itself is cracked, rotted, or pulled loose from the wall, that is structural work and needs a contractor, not just a lock repair. If the door was forced in a break-in, see the guide on securing a door after a break-in first.

How it gets fixed, and what moves the price

A locksmith checks how the door hangs, then the keeps, the gearbox, and the cylinder. Often the fix is an adjustment of the keeps or hinges and a clean and lubricate. If the gearbox is worn, it is replaced with a matching unit. If only the cylinder or key is worn, the cylinder can usually be replaced or rekeyed on its own.

What moves the price is whether it is an adjustment or a part replacement, the make and length of the lock and whether the part is in stock or has to be ordered, whether the door is stuck locked, how many doors are involved, and the time of day. You see a qualitative range up front, and the locksmith confirms the price in person after seeing the door.

If your French or patio door will not lock, describe the problem on rogerrepair.com and get one locksmith booked. Roger books one vetted local locksmith and confirms the appointment. Home and business only.