Sounds like inadequate venting for the drain lines. Could have been build this way or maybe a clog has developed in the vent pipe. Such as birds or squrrels building a nest in the vent pipe up on the ... read more
Charles-
If replacing the window is an option, then Pella Designer Series windows are available with triple-pane glass and removable miniblinds or shades inside a glass hinged panel. The blinds or sh ... read more