Sorry for the newbie question but I have a circuit breaker (Hager Series MP-E – Magnetic Switch Bipolar 30 A Curve) in my house that absolutely never tripped. This is the main CB in my house. Usage patterns of electric appliances has not changed and this thing started tripping for no obvious reason. Also when it trips it remains in the "on" position, you have to manually set it to "off" and then back to on again.
My question is, if I replace it will it change anything or I need to look somewhere else for the cause?