In another forum, a sailor who installed the Heliatos system had this to say:
"After about 4 weeks of cruising in the Med I can say that this solar hot water system works very well, hot water at the tap is obviously a joy both for showering and washing
up. The circulating pump is plugged in to my 12V boat power supply (I do have solar panels), the quite silent circulating pump does not use much electricity and is connected to a 12V timer which in summer I set for 12 hours operation. Obviously the placing of the panel/panels is crucial and on an arch (which I don't have) would be close to perfect but anything on a boat is a compromise in some way."