How to Replace a Window Sash Spring Balancer

In this video, This Old House general contractor Tom Silva repairs a window that won’t stay open.

Steps:

1. Lower both window sash and remove the screws holding the jamb liner to the side jamb.

2. Next, raise both sash and remove the remaining jamb-liner screws.

3. Pull the lower half of the jamb liner off the side jamb, and set it aside.

4. Remove both sash from the window frame, using pliers to disconnect the spring-loaded strings from each side of the sash.

5. Unscrew and remove the vinyl cover from the header over the window.

6. Yank out the staple holding each spring balancer in place. Remove the old balancers from the window header.

7. Screw a new spring-balancing mechanism to the left and right side of the header.

8. Replace the vinyl cover to the header, concealing the new mechanisms.

9. Set the top sash on the window stool. Use pliers to grasp the plastic plug attached to the end of the spring-loaded string.

10. Pull the plug down and insert it into the hole bored in the upper edge of the sash.

11. Slide the sash into the window frame, and pull down and connect the opposite string. Once both strings are attached, raise the top sash up to the header.

12. Next, connect the bottom sash to the two spring-loaded strings.

13. Insert the small vinyl guide into the slot in the lower, left corner of the bottom sash.

14. Set the bottom sash into the window frame and slide it all the way up to the header.

15. Reinstall the lower half of the jamb liner, slipping it between the sash and jamb.

16. Screw the jamb liner to the jamb.

17. Test the operation of the sash.