My trane heat pump won.t work after a power outage. Outside unit won't come on, but fan and aux will. What could be the problem. Breaker is not kicked, Had to replace relay last year. Any help will be graetly appreciated. Thanks by the way it's electric

Not sure how handy you are with a voltmeter but you need to start checking voltages at the outdoor unit. Do you have 220V power to it at the contactor? Do you have 24VAC to the boards various terminals?

A better description of the system, pics and what your results would help.

Additionally, check the capacitor at the outdoor unit. If the top appears "swollen" (like a frozen carbonated beverage can), it has failed. Be sure to disconnect power supply from unit before venturing in.