WIth some luck maybe someone on here can give some pointers, otherwise no ideas other than you need to get one of the ESPAR plug in analyzers ($200-300?) to see what the potential problem is, if it is a problem that it would log. Best bet is to find someone locally that has one and will come analyze it for you. If you can't solve the problem I would either take the boat over to an ESPAR rep, Advance Diesel Service in ANC, or pull the heater and send it to them. Last time I had problems, fried brain, I had to send it to SEA for repair since htere wasn't any local rep at the time.