Hot water heater check valve

benvenuttioki

Is there supposed to be a check valve in the water supply line to the heater, or is it internal to the water heater itself? Our cold taps quickly turn very hot within a couple of seconds after opening before cooling off. I put my hand on the supply, had wife turn on water, and could feel it quickly heat. It cooled off after the pump kicked on. Started search thinking I’d have to replace valve, but I don’t see one at all.

raybo3

This is normal. The water sitting still in the lines get hot from the heat of the boat due to outside temps and the sun hitting the boat. Do you leave your hot water heater on all the time? I only turn mine on when I know I am going to need hot water. I do not leave it on when I leave the boat.

benvenuttioki

I turn it off when we leave, but on otherwise. Hadn’t thought about radiant heating, but water is VERY hot. Enough that I need to warn guests about it. Figured it had to be heater. 

Black_Diamond

+++ to Raybo’s comment. 

benvenuttioki

Thanks! One thing off my list of chores.

redlightning

Does the water get hot after running you motors and not when you don’t?  your hot water heater is probably connected to the engine cooling?  My rinker was so when you run the motors hot water from the motors circulates in a heat exchanger around the tank and heats it. 

Check for two hoses connected that run from motors or two hose connections on the tank with no hoses connected.  This should tell you. 

benvenuttioki

It’s an issue with water whether or not engines were on.

redlightning

The water in the hoses will get warm.  I would think once you run some thru it would cool back down some.  Maybe your Hw tank power is on always.  Bad breaker or someone wired past it.
check water temp then turn on your water heater and check in an hour.