Atherm lock trouble

Question

Hi, we have several Atherm slider windows with the 90-139 locks. The locking mechanism moves up and down on two of them but the windows just will not open. We have tried forcing them but still seem like they are hanging up where the lock is. Any ideas?

Paul · Accepted Answer

Great question. If the 90-139 Acorn lock bolt is in the open position, the ball bearing wheels ( like the 87-061 for example) may be rusted and won't roll. You may also want to see if there is another safety securing lock attached to the sash at another location.