Why won't my storefront glass door lock?

It is closing time, you turn the key in the front door of the shop, and nothing happens. Or the key turns halfway and stops. Or the bolt comes out but hits the frame instead of going into it. Most glass storefront doors use the same kind of lock, and when it fails the cause is usually one of a short list.

This guide covers business, apartment, and residential doors only. Roger does not handle vehicles of any kind.

First, how a storefront lock works

An aluminum and glass storefront door has a narrow metal frame around the glass, called the stile. The lock lives inside that stile. It is a narrow deadlock with a curved hook bolt that swings out and hooks into a slot in the door frame. You work it with a key cylinder on the outside and either a thumb turn or a second key cylinder on the inside.

The cylinder screws into the lock body and has a small cam on the back. When you turn the key, the cam turns, and the cam throws the bolt. Most storefront lock trouble is in one of three places: the cylinder, the cam, or the way the door lines up with the frame.

Why the bolt won't throw, or stops partway

• The door has dropped. Storefront doors hang on pivots at the top and bottom, not hinges. As the pivots wear, the door sags toward the lock side, and the bolt no longer lines up with the slot in the frame. Look for scrape marks on the frame around the slot, or a gap at the top of the door that is wider on one side.
• The door is pressing on the bolt. Wind, building air pressure, or a weather seal pushing back can load the door against the frame so the bolt binds. If it locks when someone pushes or pulls the door firmly closed while you turn the key, this is the cause, and the fix is alignment, not force.
• Something is in the slot. Dirt, a broken piece of weatherstrip, or a bent strike in the frame can block the bolt.
• The cylinder is worn. Years of keys going in and out wear the pins, and a worn key in a worn cylinder may turn only partway. A key that feels rough or has to be jiggled is the early sign.
• The cam is wrong or loose. If the lock was recently rekeyed or the cylinder was swapped, a cylinder fitted with the wrong cam will turn freely without moving the bolt. A cam that has worked loose does the same.

Why the cylinder spins in the door

If the whole cylinder turns when you turn the key, it has come unscrewed from the lock body. A small set screw on the edge of the door, usually under the faceplate, holds it in place. When that screw backs out, the cylinder can turn with the key, and eventually someone can unscrew it from outside. Treat a spinning cylinder as a security problem, not a nuisance, and get it fixed before the next close.

What is safe to check yourself

• Push the door firmly closed, or pull it toward you if it opens out, and try the key again. If it locks, the door is out of line and needs adjusting.
• Look at the slot in the frame with a flashlight. Clear out any debris or loose weatherstrip.
• Try a different copy of the key. If one key works and another does not, the problem is the key, not the lock.
• Use a dry lock lubricant made for cylinders in the keyway. Skip oil and grease, which collect grit and make it worse over time.
• Watch the top and bottom of the door as it swings. A door that drags on the threshold or rubs the frame at the top has a pivot or closer problem.

What not to do

• Do not force the key. A key that snaps off in a storefront cylinder turns a lock adjustment into an extraction and a new cylinder.
• Do not chain, padlock, or add a hasp to the door while people are inside. If it is a required exit, it has to open from the inside without special knowledge or effort. Whether a keyed inside cylinder is allowed on your door is set by the local fire code, and the building owner or fire marshal can tell you. If the lock will not secure the door, have it repaired.
• Do not adjust the floor closer or the pivots yourself. A storefront door is heavy glass on a spring-loaded closer, and the closer and pivots are a pro job.
• Do not take apart an electric strike, a card reader, or any access control hardware. Anything behind a cover plate on electrified hardware is pro-only work.

Adjust, repair, or replace

Many storefront lock calls are small: a door realigned, a strike moved, a set screw tightened, or the right cam fitted to the cylinder. A worn cylinder is replaced and can be keyed to match your other doors. A lock body with a broken bolt, or a door that has dropped because of worn pivots, is a bigger repair, and a locksmith who handles commercial doors does both.

What moves the price is whether it is an adjustment or a part, whether the pivots or the closer also need work, how many cylinders you want rekeyed or keyed alike, whether you want restricted keys, and whether it is after hours. You see a qualitative range up front, and the locksmith confirms the price in person after seeing the door.

If you cannot lock up tonight

Stay with the property or have someone stay until it is secured, and call a locksmith for an after-hours visit. If the door will not lock because the glass or frame was damaged in a break-in, call the police first and do not touch the door until they say so. If you have more than one entrance and the other one locks properly, do not block the broken one shut with anything that would stop someone getting out from the inside.

Booking through Roger

Describe the door: storefront, office, or apartment lobby, single or double door, and what it does now (key will not turn, bolt stops short, bolt hits the frame, cylinder spins). Mention whether anyone recently rekeyed or replaced the lock. A photo of the edge of the door and the frame helps. Roger books one vetted local locksmith and confirms the appointment, so you know which company is coming. Home and business only.

You can describe the problem on rogerrepair.com and get one locksmith booked.