Thought I'd put some pics up of my hot water heater, part of my freshwater system refit.
This is the distribution system I pulled. This deals with the cold water side only. It seems whoever put it together was just digging through his grab bag of plumbing goodies to cobble this together
https://goo.gl/photos/zqMtpcxzmMSQsf59A
This is my simplified version..
https://goo.gl/photos/NVta3wsNbBySbiwN9
And everything back on the heater. I also installed a mixing valve on the hot water side. I don't know if anyone else has this problem, but my hot water was SCALDING, even when we weren't using the heat off the engine. So this valve will keep the hot side below 34 degrees C.
https://goo.gl/photos/scgkomWiFCkWCP5s7
Also.. in case you're wondering, my partner in crime thought she'd look better in metallic copper, so there's that.
Hears to a hot shower in the Bahamas someday.
I don't know if you already read about it, but there is a Westerbeke service bulletin out on plumbing the water heater with a bypass. It's been talked about here before and a copy is available on Seadragon's web site. Without it, some installations run hot. We sail in ice water, so it hasn't been an issue up here in Alaska without it.
http://www.sailingseadragon.com/Manuals/DomesticHotWaterHeaterSBulletin7July1980.pdf
Attached is the pdf