window hard to open/close

It certainly could be the case that your balances are causing the problem. Hard-to-open windows are a typical sign of worn-out balances. You might benefit from replacing the balances on both sides of your window, but I can't say without seeing. If you'd like, remove a balance from the window and take a photo. You can send it in for us to take a look at.

You might need to replace them if they are old. The grease dries up on the spirals and can give you problems while opening and closing. If you want, try adding some white grease to the spirals and see if that helps. Otherwise, the balances might need an adjustment. Take a charging tool like our 75-006 and give the spirals another turn or two to see if it helps. Don't go with too much more than two turns, or you risk killing your balances once and for all. If the balances should fail or continue not to work after you try greasing and charging them, you will need new balances.