New coils won't hold up the sash

Question

My new Swisco coils are not holding the window up.

I actually ordered the pivot shoes as well as 4x S190-640 springs back in March. At that time, my sash weighed 9.7 kg (21.4 lbs). I installed it, and everything worked fine.

However, as my glass had a leak, I had to replace the glass in May. Unfortunately, the newer glass turned out to be thicker and, therefore, heavier.

My existing configuration (with the S190-640 springs) wasn't sufficient to handle this. Logically, as the new sash weighed 12.5 kg, and the 4x S190-640 springs can only handle about 10.8 kg (24 lbs). I therefore ordered the 4x 740 springs to handle the new configuration. I reused all the (already new) parts, like the pivot shoes of the existing configuration, as I believe they fit the newer springs as well. However, I ordered these parts as well to have spares, just to be sure (I'm in Europe, the Netherlands).

Casey · Accepted Answer

Hello,

I agree that it sounds like you would need to use two S190-740 coil springs on each side if the new glass increased your sash weight to 27-1/2 pounds. Take a look and let us know if you need anything else. Thank you!