broken constant force balance(s)

Question

This is a 23 year old single hung builder unit likely Champion or similar. Window is 32x48 and I think 15-186, 15-180, S190-540 look right but no sure. Please help

Bob · Accepted Answer

Hello there. This does indeed like a 15-180 Pivot Shoe, which works with Series 190 Coil Balance springs (and the 15-186 housing and 15-182 drum). As far as the spring weight to select, it's best to look for a stamp on the old coil spring that confirms this, or to weigh the window sash. That exact weight can be used to calculate the spring weights needed. See below.