Fix Double Hung Window Sash Cords

Have you ever had the problem where your window won't stay up? Window sashes have counter balances concealed in the window frame that balance the weight of the window so that they don't slide down in the frame. The problem is sometimes they break, or freeze up, depending on the counter balance system.

Here's a shot of a problem counter balancing system. Note: You can click on all photos to enlarge them.

Old Windows
My 100 year old house has old and new windows. The 100 year old windows have "sash weights"— heavy weights attached to cords inside the window frames with cords that go over pulleys at the top of the frame. A few of these have broken cords, which would mean taking the window frame apart. This article is not about fixing them.

New Windows
The new windows on the second floor though, were replaced by the previous home owners. They replaced them with Anderson Double Hung windows (double hung means they have 2 moving sashes, a top and bottom sash).

These might be about 15 years old? I don't really know, but they have a different mechanism for counter balancing the sash. At first sight it is not obvious how to fix these things, but I was able to find a good PDF online that explained the whole process in detail (see top PDF). I'm not sure how many windows work like these now, but perhaps your windows are similar, even if they are not Anderson, or of the same vintage.

Are Your Windows Under Warranty?
First check though to see if your windows are under warranty. I didn't bother with mine, as I'm fairly sure they are out of warranty, and we were not the original purchasers. If they are, you can schedule a service call to have them fixed for free, or at least the part might be free, and you'd pay for service. You'll typically need to have proof of purchase date, for warranties to be honored.

Here's How to Replace the Counter Balance Springs on Anderson Double Hung Windows. To be specific, these are the replacement steps for: Anderson Perma-sheild Narroline Double-Hung windows. If you don't have these types of Anderson windows, you might find your Anderson window replacement balance parts here on the Anderson website.

Shown above is the side of the window. You can see that the upper sash does not stay up and both cords (there's one for the upper sash and one for the lower sash) are slack and do not recoil into the window as they are supposed to. Note: You can click on photos to enlarge them.

Here's the "sash counter balance" unit we are going to replace. There's one of these boxes concealed in the upper left and upper right top of the window frame. When working properly, the cords should retract into the box. This box has been corroded by water damage I believe. What follows is how to get at that box.

Now I apologize, but I don't have the very first photo of the window intact. This photo shows after removing from the vinyl piece that was covering what is shown in the picture as wood. After you remove all of the screws (see photo below too for removing the top 2 screws) you can remove the vinyl "jamb liner" as it is called, by flexing it slightly at the bottom and sliding it down (have both sashes in the upper most position when you do this).

There are 2 screws at the top of the jamb liner that can only be removed when you have both window sashes have been lowered all the way down.

With the jamb liner removed, and both sashes in the lowered position, you will be able to swing the inner most sash out of the window frame.

Looking a the side of the pulled out sash, you will see a recess in the side of the sash, where the cord is anchored by a plastic tube piece. Grab hold of the cord, to take the tension, and pull the end of the cord out of the sash. Do not let go of the cord suddenly, as it is under high tension and doing so could case injury, and or counter balance unit damage. Gently let the cord retract and release (see photos below). Do the same with the other side. Only one of my sash balancers was frozen (the right side), so it of course is no longer under any tension, as it doesn't retract). Repeat the same steps for the upper sash.

Here's the cord out of the sash.

Here are the cords on the working side, fully retracted into the top of the window frame.

Here are the cords on the non-working side, not retracting into the top of the window frame.

Remove the "head jamb liner" screws, and then bend it slightly and pull downwards to remove it. This will expose the 2 sash balancer units. This view is from the outside of the house, as I was able to work from a roof just below.

My head jamb liner was stuck toward the inside edge. I ended up having to pry it down with a screwdriver. Be careful not to damage this piece though.

And here is the culprit. This box is not retracting the sash cords as it should be.

Remove the staple holding it in. I was surprised that their was just one. Your model might have screws to remove instead. Then simply pull the balancer out.

As shown before. Here's the box removed.

And here's with the end of the unit pried open to see what was inside. There's a coiled spring, that seems to be lined with rubber. When working properly, the spring should uncoil and wrap the cord around it, and helping to lift the window sash.

That's all the photos I have for now, as I've not put the new boxes in yet. I did order the Anderson sash balancers at Home Depot. I brought the old, none-working box in and they were able to make a phone call, read off the number on the box, and order a new box. They do not stock these items. I also couldn't find any local Anderson dealers that stock these, as their seem to be too many variations to make it worthwhile to keep all of them on hand.

Ideally you would also bring with you any information that is etched into the corner of the window glass. As there are codes there that help identify your particular replacement unit.

I actually ordered 2, as I figured I might as well replace both while the boxes were accessible. I was surprised to find that each unit was only $14.00. I expect to pay more for everything these days. The order took about 5 business days to come in.

I picked them up today. I'll shoot them and show the install, although all you do is reverse the steps of course, so maybe nothing more is needed--Peter

My Standard Disclaimer: This is what I did. This does not mean this is the best way, the right way, to building code, or even safe for your needs. So you are on your own with your project. I make no promises about the information presented here. I'm just a do-it-yourselfer, not a professional at all, sharing my story. So if something goes wrong with your project, you are on your own. Good luck, and have fun!

All content and photos, copyright 2009, Dover Projects.
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  1. Perfect - I have the same window installed as a pair in my attic bedroom. For some reason the two top thermo-pane sashes cracked last month. I am trying to figure out how to replace them and couldn't figure out how to get them out. I was on right track but having trouble with the jamb liner. Its hard to bend it enough to pull it down and out but knowing that's the right thing I will get more forceful. Thanks!

  2. jeanne, I know what you mean about them not coming out without bending and forcing it. The illustration of that step (in the Anderson PDF) shows the head linder sliding right down, but I don't see how that is possible. I flexed mine in the middle and got one side out, then came the other. --Peter

  3. Did you have to pay for shipping?? Or was that included in the $14.00??

  4. Sorry I missed your comment. My e-mail notification must be misfiring. The shipping was included.

  5. This was an EXTRMELY helpfull site. The pictures were great. Thanks for the help !!

  6. Dear Jeanne,
    Anderson has 20 years warranty if the glass cracks due negative pressure, considered a factory defect. (10 years on non-glass items.)They will replace the entire sash free of charge. They even had a contractor test/check the others at my house and replaced ones that failed before they even cracked. NO CHARGE.

  7. Thank you so much for the pictures, it really helped a lot. Just to add a few more comments, to place the top piece back on, slide it in on one side first in a diagonal, and then bend it so the center part will be bowing down. Then slide the other side in, it worked well for me on both windows.

    Also be careful when removing the sash, pay attention to the vinyl jamb liner piece that does not come out, the one on the top left. Make sure the cord clears the vinyl rail before pulling the sash out. You have to pull the cord out of the way slightly otherwise the vinyl rail might damage.

    Another observation. A few of the cords on the balancers broke, after removing the sashes I realized that the reason for the broken cords was that the top molding was nailed into the balancers. That was why the window never worked well. I would recommend removing the top molding first to see if this will solve the problem first. If it does then you might not need to replace the balancers.

  8. To both "anonymous's" thanks for the additional inputs!--Peter

  9. NEW!!! DOVER PROJECTS ON FACEBOOK! Join in with your DIY spirit! Click on the BIG blue box for "Facebook, Dover Projects" in the right column above! See you there!--Peter

  10. i did this repair on a new set of windows 15 years ago as my men drove screws into the balancer boxes from above when joining a double unit...had to pry the boxes out and snap off the screws and replace the balancers they going to do 4-5 windows in a house with old, frozen balancers....wondering how many hours total to me an approximate overall idea of how long each window took you would be a help to me...also, the balancers are different for left/right and size/weight of individual sash...example is a bathroom doublehung narrowline might be a 15'' tall sash..the balancer is different than a 28'' tall sash....both cord and spring strength..these windows remain unchanged since 1968....with design the same and parts available..replacing this entire window in a brick house would be impossible except to put a vinyl replacement inside of the I think it's the better job to replace the original parts..

  11. my house was built 2 yrs ago with anderson windows that have the sash cords. is this considered a new window?

  12. It's great that you have so many pictures and guiding instructions. I wouldn't know what to do if these pictures weren't here.

  13. Thank You Peter! This was a project that I've put off a long time because I had no idea what I would be getting into. Your site was perfect for helping me replace the faulty balancers on my 1987 Anderson windows. Steve

  14. Peter, This was a GREAT help. I had tried to investigate mine, but failed when I was attempting to remove the 'jam liner and sashes all at once. Ah, the trick is put the sashes in the top halve of the frame. Thanks a bunch.
    By the way, you were the only one I found to have something about this.
    Thanks for waht you do.

  15. Sure thing Tom. Glad it help!—Peter

  16. Peter - I appreciate the detailed photos. Now... Is their some trick to removing the head jamb liner, beyond prying with a screwdriver? Mine is really stuck on the inside edge, even though there do not seem to be any nails driven through it. Also, I've run a knife between the top jamb liner and the molding. It seems like it should be free, yet it isn't. Thanks in advance - Fred Rednor


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