Critters!!! Our Hot tub would not fire up. Error code, pilot light not detected. However pilot light did ignite and was operational. That meant the pilot light sensor was faulty. Many threads with similar issues on this site recommended that the main board is bad, and to replace it. It seemed drastic, and it was a $300 part (found one at mypoolyard dot com), but I listened to the experts and ordered the part. When removing the board, look what I found...a fried treefrog!!! It must have crawled under the board under the transformer/capacitor/sensor then shorted out and burnt, resulting in burned-out sensor circuit on the board. I was surprised that the main board continued to operate and report errors earlier. I replaced the main board... now the hot tub is working again, yay!!! I plugged up all the wire through holes so no more critters could get to the main board. I hope that never happens again. Lesson learned...no matter how new or how old, if an animal gets into the unit, it can cause all kinds of damage. I feel sorry for the poor treefrog 
...RIP
...RIP
