good afternoon kevinrousse ......... if you have the manual. there the manufacturer places the most common faults ,,,,,, otherwise and if you have a notion you can do it ,,,, with the equipment unplugged and very carefully you take out the environment and freezing sensors and measure the k, what most likely that they are damaged and activates the relay ,,,,,,,,,,, 2nd, you must check the connection between the card's output and the terminal of the outdoor unit ,,,,,,, 3rd ro you should check the trainer just in case ,,,,,,,,,, and if you have no notion it is preferable that you call a technician to check it for you ,,,, these tests are delicate and to save you money go out but the situation and for personal and team safety ,,,,,,,,,, luck and value the answer