Hi all, I wanted to post an informational (at least it was for me) comment after my 2009 350/370 DA developed a water leak in the pressurized water system that resulted in the water pump kicking on every few seconds. I started by tearing into every pressurized system (head shower and sink, cabin galley sink) and found them dry under pressure, so no luck. Then I read the lower half of the pump could be bad, so I replaced the pump. No luck. Then I tested the Temp/Pressure release valve on the water heater and it leaked a bit. A-HA! So, I replaced that (hard to find a 75 PSI TP valve btw), flipped on the pump to pressurize the system, and bzzzzt....the pump kicked right back on so the problem remained. SO it WASN'T the water heater TP valve, I couldn't see anything coming from the water heater, it wasn't any of the shower/sink fittings I could reach. I was out of guesses and called in a professional mechanic. After some pro-level diagnostic work, turns out the one-way valve on the water hose connect for city-water supply was leaking. On my boat, that connect is near the power line connections on the transom in a locker. That was a place I hadn't checked. It is winter in TN where my boat resides so I haven't been able to replace that connect and pressurize it to check, but I am hopeful that's it. Just another place to check in case your boat develops a hard-to-identify leak in the water pressure lines. Good luck all.
