Paella window balance springs

Hi there, Steve.

Thanks for reaching out to us. You shouldn't have to replace the window if the balances are all that's broken. In order to help, I will need to see a photo of the pivot shoe removed from the window track. That will allow me to identify the compatible balance hardware. If there aren't any cutouts in the window already then you will need to make one as shown in the video below. Could you also weigh the window sash and tell us the precise weight?

This reminds me of our 15-251 that uses the Series 160 coil springs. Note that it looks like your balance is stamped 4.5 which indicates the spring weight. One 4.5-pound spring on each side of the window is meant to support a sash weighing 9 pounds which would be too strong for the sash weight you've given. You could always double-check the sash weight if you wanted to be safe. However, with a 7-pound sash, you can use one S160-3 3.5-pound coil spring on each side of the window. This will total 7 pounds of overall support. 

As for the tilt latch, start by taking a look at the 26-464. Review the specifications and see how they compare with yours.