Symptoms
- Visible gap at the edge when fully cranked closed
- Drafts along one side of the sash
- Lock doesn't fully engage
- Window feels loose in the frame
Likely causes
- CommonWorn crank mechanism not pulling the sash all the way inGear wear reduces how far the operator can close the window.
- CommonLoose or worn hingesSagging hinges let the sash droop out of alignment with the frame.
- PossibleWeatherstripping compressed or damagedOld foam or bulb seals lose their ability to compress and seal.
- PossibleLock/keeper misalignedIf the lock can't fully engage, the crank may stop short of full closure.
What to do
- Crank the window fully closed and check where the gap is largest.
- Tighten all hinge screws; if the screw holes are stripped, use slightly longer screws or wood filler plus new screws for wood frames.
- Check the multi-point lock (if present) engages all the way; adjust the keeper position if it's catching early.
- Inspect the weatherstripping around the sash for flat, torn, or missing sections and replace as needed.
- Test the crank operator for full travel; if it stops short, the gear teeth may be worn and the operator may need replacing.
- With the window closed, look from outside for daylight around the edges to confirm the fix worked.
- Recheck the lock closes with a firm but not forced action once adjustments are done.
Tools and parts
- Screwdriver
- Wood filler (if needed)
Casement window weatherstrippingSearch: “casement window weatherstrip seal”
Casement window crank operatorSearch: “casement window crank operator replacement”
When to call a pro
Call a window repair company if the sash itself has sagged out of square from worn hinges, since that may need frame-level correction.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.