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Latches, Locks & Keepers

Locks are half of the mechanism that holds your window shut. They are located on every model of window with a moving sash, but vary in design and placement depending on the type of window, manufacturer and style.

Keepers are the other half of the mechanism. The hook of the lock fits inside the keeper, which is secured to another sash or the deadlight frame.

Latch mechanisms are commonly found in casement windows, which have an internal locking mechanism that grabs the keepers on the sash at multiple points. Patio doors also use an internal latch to lock.

Signs of a broken lock

  • Window/door will not lock

  • Lock is difficult to operate

  • Keeper is visibly bent

  • Casement/door latch handle feels loose and does not move the lock

Why do locks break?

Locks typically break from sash warping, lack of maintenance or user/installer error.

Sashes, especially vinyl, will warp from heat changes in the environment. This warping causes the lock and keeper to fall out of alignment and require more force to close. The result is bent hardware. Please, lock your window when you are not using it to vent to stop and reverse sash warping.

[Warped sash image]

Locks need regular lubrication to prevent friction and corrosion. A Window Wellness Service © includes lock lubrication and a manual reset of the lock and keeper's alignment when necessary. 

Sometimes, window users or contractors will misuse locks and keepers. We have seen:

  • Locks that have been engaged while the window was open and slammed down on the keeper, bending it.

  • Sashes improperly seated with the lock misaligned. The user attempted to lock it and bent the keeper with the lock.

  • Locks installed off-register or with the keeper backwards.

  • Locks lubricated with white lithium grease, which ages poorly, becomes chunky and yellows. We recommend 100% silicone lubricant for windows and all their parts.

[Bent or messed up locks and keepers]

Types of Locks

Locks come in a variety of styles. We have several standard models in stock and can order new locks and keepers to match most designs if they need to be replaced.

[collage of  locks]

Single/double hung lock & keeper

Single and double hung windows typically have a lock attached to the bottom sash and a keeper attached to the upper sash or deadlight. The lock slides into the keeper's groove to connect the two sashes.

[Collage of single hung lock and keeper]

Casement locking system

Casement windows have two different styles of locks. For both, the keepers are attached to the sash at 1-3 points opposite of the operator. The first type has a latch and handle to grab each individual keeper. The second type has a single handle that operates all the latches that grab the keepers. The type of locking system a casement has depends on its size, weight and manufacturer.

[Collage of casement locking system]

Patio door lock

Patio doors have a lock and keeper system built into the handle. The keeper is attached to the door's frame. Often, these locks are poorly adjusted or put together wrong by handymen attempting to repair them. Usually, the keeper is misaligned with the latch. If the lock handle is loose and moves freely, taking the lock apart and reassembling it will often resolve a patio door that fails to lock.

[Collage of Patio Door lock]



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