on some units they put a snap disc on the pipe between the first set of fins....that failed the design....now they want it somewhere else,,,near that set of fins,,,,the on point should be 130 degrees....amazon has that....important to remember...ammonia boils and issue arise with over boiling,,,then you have to stop and remove the unit....turn it upside down for a night or so.....then install a new snap disc on the fins .....best place is near the original site.....on the fins or attached at that location...how you do it is to catch the heat to turn on the fans.....I put a secondary switch on the front of the eyebrow to manage just in case.....they are connected with a 1 amp fuse to the snap disc and a bypass wire to the fans....they messed up on the design....and the thermistor for some units cost a 120 bucks or so....so if it tests ok....you can ask gemini on specs....do not mess with that because on some units it snaps on to the ciricuit board and is now very rare to get...DOMETIC 2951380514 SENSOR COMPLETE....so....just assume the circuit board is ok....change out the snap disc etc....turn it upside down to move the ammonia blockage to the right location in the system.....its a distillery...short answer,,,