I have a inter-therm unit , model e2eb-012hb replaced contactor because heating unit would start up then shut off and contactor would click as if trying to come on, as I said I just replaced contactor with contactor #624722 which replaces contactor #621909 but unit still doing same thing checked heating coils (no breaks, looks ok) any ideas about what to check next?
Thanks

I suggest checking incoming voltage to the contactor. If 240 volts (+/-) is found, check the outgoing voltage from the contactor.

Here's a link to the service manual. http://www.nordyne.com/Literature/359a.pdf
The wiring diagram for your furnace is on page 18.