Andersen 939 Narroline Sash Balancer

Easy to install; fully restored the function of my old windows. Glad to see these can still be had...the old Andersen windows are built like tanks!

Product was exact replacement for original sash assist device.

Per previous research I was aware that the wood frame of the window would have to be notched to replace the old style balance with this new style per the mounting tab on the end while the old ones had a through hole to mount. Also the replacement is a little wider than the old one and took some persuasion to get into the frame pocked. Had to notch full depth about 3/16 inch across width for main body to sit into pocket and a smaller, less deep notch for the mounting tab. Works great.

Timely delivery. Worked and installed easily

My house was built in 1986, has Andersen windows and most of the balancers are either broken or barely operational. It has 13 windows with #927 (now it is #939) balancers for a total of 26 balancers. Plus I have other window sizes with different balancer numbers. It is quickly becoming a problem.If balancers break on both sides of the window, you can no longer keep the window open. I have replaced a few of them last year and just recently. Looking inside I think they are way too expensive for what they are. There are 2 plastic pulleys and 2 torsion springs inside. Some pulleys break over time. All springs are becoming too difficult to wind due to a lack of lubrication and strings break because of that. It is a miracle that some balancers survived over 35 years in my house. I do not expect new balancers to last half that long. I think it is a deficient design, but you have to live with what you have.When I take an old balancer out and it is not broken yet, I open it and lubricate pulleys and springs. Hopefully it will prolong their life for a few years. A little trick I'd like to share - do window work when weather is sufficiently warm. You need that to make jamb liners flexible during removal and installation, otherwise you will just break them.This is also the time to fix any rotten wood in window frames and sashes and repaint if needed. After installation I would suggest to apply a flexible sealant to jamb liners to sill joints. This is to prevent future rot.

The balancers need to be replaced when the sash cord breaks or the retraction mechanism seizes. The replacement balances work fine, but I wish the originals hadn't broken in the first place. To be fair my windows are over 20 years old and exposed to severe weather with salt water spray.Before starting go to YouTube and watch the video called "How to replace an Andersen window balance". The job is not intuitive, and you could damage the window if you are not careful. Be sure to place a thin piece of cardboard on the inside of the window sill (called the stool) to prevent scratching when removing and reinstalling the plastic jamb liner.Andersen has a chart for identifying which balancer to order. You need to know the visible glass size (width and height) of the lower sash to identify the balancer number. All my windows use the 939 Narroline.Each window has two balancers, I recommend replacing both even if only one is broken.

Product fit perfectly.

These fit my 1980's era windows. Same item fits left and right sides though the original was held in place by clip instead of screws.