Fan cycles on/off, is noisy & heat is uneven

We just bought the house so I don't know the history.
The fan is quite noisy and seems to turn on/off constantly??

The fan cycles on/off about every 20 seconds only in convect mode so I'm suspecting the convection fan?

via Fan cycles on/off, is noisy & heat is uneven
by larkamr@aesecurity.ca