We like a comfortable, warm shower after a day of sailing.  Soon after adopting our new Shearwater, we restored the water system, removed about 25' of tubing installed by previous owners (everything kept working), and took our first shower.

Showering on a boat is, well, interesting.  On our previous boats, hot water was generated by capturing the waste heat from the engine and storing it in a tank that resembled a home hot water tank.  Since this Gemini has an outboard, waste hot water capture was not practical.

She came equipped with a Poloma Tankless propane water heater.  The unit is located in our head and is  not vented.  We had some concern about using a propane appliance without proper venting so we installed a fire and carbon monoxide detector, but that is another story.  Tankless water heaters detect the flow of water and heat it to a fixed temperature, automatically cycling as needed.  Our unit produced an alternating flow of very hot water (I set it to 140 degrees for dish washing), and much cooler water, making showering uncomfortable.

The solution is a "tempering valve."   These valves, invented by James Watts of steam engine fame, take in cold water and hot water and produce a constant warm water that can be temperature set by the valve on top.

On the Shearwater, we feed the hot water tap on the head shower (and eventually the cockpit shower), with tempered water.  We feed the hot water tap at the galley with full hot water to make dish cleanup easier.

The Watts L70A-T low temperature threaded tempering valve was under $35 from PexSupply.  It took about 15 minutes to install after removing an extensive pile of unused hoses, and works without attention.  One side effect, when our grandchild turns on the hot water faucet to wash her hands, there is no chance of a burn. 

Untangling the Tangle

One of our big improvements as we restored our Gemini was the removal of equipment that had been installed by the previous owners and just abandoned over time.  This photo is typical of what we found when we opened up inspection ports to repair, reroute, clean or adjust portions of the boat's systems.  Especially interesting are the green and blue green fittings that had leaked over the years.  When we initially powered up the fresh water pump, it cycled every thirty seconds or so to keep pressure on the system.  Now, a dozen new hose clamps and 30 feet less hose, it does not cycle at all and can be left on whenever we are on board. 

Slightly visible in the photograph is some ordinary household solid copper wiring used by a frugal owner to install 110V electrical wiring.  Most has been removed, some remains, and the active portions have been replaced with proper marine wiring and ground fault protected outlets.