I do not know if others have had water heater problems, but I thought I should post something about my hot water heater issues that might help others avoid the problem I had. On our crossing to the Caribbean, we lost all of our fresh water - into the bilge and over the side. The bilge pump sure did its job.
No one noticed that the bilge pump was running way too much, and when we tried to use the galley faucet there was no water. At first I assumed the pump had failed, but when I went down into the engine room I saw water pouring out of the front of the hot water heater. The main water tank was empty by then.
We had to scramble to bypass the water heater (Isotemp 40L) and found that the main gasket that holds the heating element assembly in the tank had ruptured. Upon taking it apart it was found completely carbonized and literally fell apart. Bypassing the water system to allow us to continue using fresh water was no small task either, but we managed to cobble together a short hose to seal off the intake and outtake at the heater. The problem there is that BOTH sides of the water passthrough are pressurized - very surprising and we could not figure out how that could be true (the Amel drawings show exactly what is expected, so presumably someone modified the installation). Normally only the cold water side would be pressurized upstream of the water heater.
A quick call to Great Water in Florida worked and they rushed out spare parts. We had to replace the main gasket, faceplate, and the 230V electric element as well. They had all corroded.
I have heard others talk of a zinc, but I do not see any and the manual is different from the one in the boat.
Fortunately we were able to keep our crossing schedule and did not have to return to port, thanks to the water maker.
After this failure, I keep spare water heater parts around. It seems that 10 years is about it for the gaskets and elements. It is worth replacing them early on. This is not a problem I would have planned for, as water heaters seem pretty benign, but have learned how important it is.
s/v Phantom Amel 54 #044