Tech Wiki

Fresh Water Head and Overflow Control

by R. Norquist

I got a little tired of the Head Overflowing when someone forgot to leave the handle down. I decided to convert the smaller starboard Fresh Water Tank to a dedicated fresh water supply for the head. The starboard water tank is about the same size as the holding tank. This is great because you reduce the risk of overfilling the waste tank. I added a 1/2" Tee off the inlet sea cock and put a 1/2" ball valve and a one way check valve on the fresh water inlet side of the Tee. Then disconnected the stabbed fresh water tank from the fresh water supply system and ran a direct line from the water tank to the Tee. Then connected to the head inlet line to the other side of the Tee.

End result and benefits:

  1. I don't need to use the inlet sea cock. It stays shut. I only need to open the ball valve to the fresh water tank.
  2. The head never overflows. The top of the head is is just a little higher than the top of the water tank.
  3. The head odor disappeared or at least is better. You don't have all those sea water microbes dying and causing additional odor.
  4. We only use the large stern water tank for drinkable water. We use it more and this keep things fresher.

THIS IS NOT A GOOD IDEA. Here's why:,7564.0.html [Stu - 6/8/2013]