THe fan to our unit won't come on in any setting.

The emg heat light comes on after a few minutes when the heat is turned on,

I can hear relays tripping and the fan should turn on and off.

It is a cylinder blower and not a fan with a few blades. They go off like this:

1-1----1----------------------1. both when they should be turning on and off .

I don't see any belt pieces and the motor never kicks on.

Could be the blower relay or possibly the blower motor itself. They are direct drive. No belts... You would need to test and see if you are getting voltage to the motor...