This is new hot water tank weekend. The hot water tank is sort of behind the
diesel furnace, so before I put in the new Webasto it made sense to replace the
20 plus-year-old hot Atwood marine hot water tank. (It was developing rust
marks along the bottom, and a tiny puddle had started to form).

When removing the tank today, I discovered something that might be of interest
to to others. The hot water tank heats water electrically as well as by
circulating
engine coolant through a heat transfer coil. The hose connections between the
engine and the tank were on the back of the old unit.

After I disconnected the power, pulled up the mounting screws, unhooked the
water lines, and drained the water from the unit I decided to pull it forward
to get better access to the engine hoses.

"Rip!"

Even though I replaced the engine last winter, the installer just plumbed a
union between the engine hose and the existing hose to the back of the water
tank. The hose was probably 20 years old, just like the water tank, and was so
badly rotten that simply moving the tank caused it to fail.

Had this hose failed underway, all the engine coolant would have been pumped
into the bilge. If that had happened, failure to shut down quickly enough might
have damaged the engine.

The new unit has all the fittings on the front, where the *new* hose will
connect.
Those with a very old hot water tank, especially one with the fittings out of
sight on the back, might do well to check the engine coolant hoses.