Andersen 531 Narroline Sash Balancer

These fit was perfect with a little retro work that was spelled out in the directions

Fit perfectly

The perfect fit

Be aware that to install this in pre-1980 Andersen windows you will need to chisel or rout a 3/16 recess in the window frame to install to accomodate the lip with the screw holes on one end of the balancer as stated in the instructions that come with the replacement. I used a sharp 1/2 wood chisel. I strongly recommend watching the video for this project on Andersens, Swiscos or Youtubes websites. Its not as easy as the video makes it look. Particularly with smaller windows. Always replace both balancers. Once installed, the balancers worked fine.

extended the life of my windows

Easy installation once you get the sashes out of the window casing. Good directions on YouTube and on the direction sheet that came with the product.slightly different construction than the ones that were in the 40-year-old window. Slight modifications made them fit just right.

it fixed the window

Works well to replace the counterweights in my Anderson windows.

the hardest part is to remove the plastic track. i put some dawn detergent on it to make it slippery to take off and then to wiggle it back into place. the balance was an exact match and fit into the available slot without any additional work. the window functions better than new.

This fit as predicted by Anderson references (always check!). My window was NOT the tempered glass. Some installation tips say that the top panel that covers these should be replaced, but it can go right back in. If you have never done these before, just watch videos, read instructions, and work carefully. You may have to remove trim on left side to get the track out. If you break a piece you probably can replace it, but not cheap! If you can afford it, do both since you already have the window apart.