Hot water tank question

zaverin1

so I drained my fresh water tank and put my hot water tank bypass hose on. Home made in my case lol 
been using it for years.
this will be the first time that I will possibly run the boat over the Next few days without water in the tank.
will my engine circulating hot water damage the hot water tank since there is no water?
i know it's a closed loop system 
hot in and out.
i know I am not going to flood my aft because tank lines are unhooked but will it damage the tank?

Hamdog

Nope. The hot water from the engine just runs thru a heat exchanger meaning it only has an external effect on your water heater. Kind of like applying heat to the outside of an empty glass.......won't hurt anything.

MarkB

It shouldn't be a problem because all it's doing is taking the hot water from the exit of the engine and putting it through the hot water tank before it returns to the lake/ocean.  The water won't get hotter than what it exits from the engine block and the hoses see that temperature always anyhow.

howardrams

The hot water circulating through from the engine won't hurt anything but don't turn the hot water circuit breaker "on" while you're on shore power with a dry tank.

zaverin1

Thank you 

youstolemybeer

Turn off the breaker to the water heater (make sure the heater is on its own circuit) and cover the breaker with electric tape. Or find the water heater power wire and disconnect it. The heater element inside does not like to be on and dry.

rasbury

dumb question on my part, but why do all this?

zaverin1

To winterize the water system and not  waste 6 or 10 gal of red pop

howardrams

I think the guys in Florida like to tease us northerners.

Stodge

At least we don't have to deal with salt water.

youstolemybeer

rasbury said:

dumb question on my part, but why do all this?

The element inside the heater is designed to be submerged in water. If it has voltage to it while dry it will fry and break.. Covering the breaker after it is turned off makes sure that later in life when his S.O says "Honey, I would love to have the shower working again," all he has to do is remove the bypass and hit the breaker. Been there done that