Some may be aware of Louisville engineering. If not , consider them for electronics on aquahot. They had 30 aquahot in job trailers for fiber optic work. Over time they decided to reverse engineer the burner boxes and the circuit boards to maintain their own aquahot. I have learned a lot about aquahot while owning one. More than many service centers seem to know. Louisville engineering taught me more about aquahot electronics in a couple phone conversations than anyone else including aquahot service techs. They test the burner boxes and the circuit boards in heat cold and vibration cycles. They will rebuild these components. I sent them two burner boxes that I thought had failed and learned both were fine. The circuit board had issues that may be temporarily solved by replaceing the burner box but only for a while. The service was very quick . Phone calls and follow up were excellent. Told me how the burner boxes and circuit board work and while many folks think the new digital burner boxes do not last, often is weak transistors and other components on the circuit board that cause a perceived burner box failure. William Borie is the man. They have staff there till midnight their time . Absolutely the best knowledge source I have come across . John Carillo is another and William speaks very highly of John. Louisville engineering@att.net. 502 553 8210.