18 or 19?

Question

Existing window has 3 coils and is labeled 18, but they are hard to open.  Can I increase the tension by 1 pound to help make opening the window easier?  Will this disrupt the window operation?

Tom · Accepted Answer

That's a tricky question. You first have to consider if your windows are hard to open because the coils are the wrong calibration, or if they're just old and locking up. You don't want to get a stronger balance only to find out it's too strong. Then your window will be harder to close, which is no good.

If you want to know for sure, you should weigh your sash on a scale. That will tell you beyond any shadow of a doubt which spring to get.