We have an 11 gallon Seaward S-1200 hot water heater.

We just spent our first weekend of the season on-board and on Sunday when I was doing the dishes I noticed that the water was just lukewarm. I turned on just the hot water faucet and the water was warmish with discernible bursts of cold water mixed in.

I then went to the head and tried the hot water faucet there. I let it run for quite a while and the water was not as cold as it was from the cold water tap but it wasn't what you would call warm.

I thought that maybe my husband had used a bunch of hot water before me so I left it for an hour and then went back and ran the galley faucet and then the head faucet with the same results.

Now the strange part. For some reason I decided to experiment by turning on the hot water faucet in the head while running the hot water faucet in the galley. Boom, super hot, scalding water starts flowing in the galley. Cold water coming out of the hot water faucet in the head.

The faucet in the galley is within 2 feet of the water heater. The faucet in the head is a good 10 feet or so.

Clearly the heat element is working because the water that comes out of galley faucet when the head faucet is turned on would give you 3rd degree burns.

Scratching my head over this one.