Still have a question? ask your own! First call’s technician was professional and honest, and said neither a new motor nor a new furnace were necessary.. Almost any home, but best for homes where lots of people won't need lots of hot water at the same time. Used the whole bottle overnight to unblock a slow running bathroom (bath and loo) pipe water now runs freely - exceeded my expectations! The mysterious "." is a constant value called the. This covers the actual condition.