Window Coil Balance

Question

I have a broken Coil Balance that matches your series 160. There is no number or markings stamped on the old coil. I have a window that weighs 13 # and has a double coil on each side of the window. Is the 3.5 spring weight the correct size for my window. Do you also recommend replace all 4 coil balances on the window with on one coil balance broken? Final what is the outside diameter of Series 160 coil balance with a spring weight of 3.5.

Tom · Accepted Answer

Thanks for reaching out to us. Our S160-3 should work for your 13 pound sash, yes. Two 3.5 pound springs on each side of the window add up to 14 pounds of support, which is one pound more than what you need but that should still be fine. You probably won't notice the difference during normal operation.

I do recommend replacing all four springs if only one is damaged, yes. You never want to mix old and new springs as a rule. The older these get, the less tension they have, so what will end up happening is the one new spring you buy will have to work twice as hard to pick up the slack for its weaker partners. That results in it failing fairly early into its lifespan.

Lastly, for your final question, I don't know the diameter of these springs off the top of my head. That's not generally a relevant dimension. As long as your shoe is 1-1/4" wide and as long as your spring is 1/2" thick then I wouldn't worry about size.