Water heater question

[butchrobbins]

How long should it take for a 12 gallon tank tp get hot after starting the engine?

 

[Don S/V ILLusion]

Perhaps incorrectly but I infer from the question it isn't (getting hot). Check for an air lock particularly if you have recently changed the antifreeze or done any cooling system work.
Even at idle, it should at least we warm in 1 hour or less.

 

[Richard Bryer]

I would say an hour would be certainly plenty- our 6 gal tank heats to hot in 1/2 hour easily with our 3GMF engine running at about 2500rpm

 

[Bob S]

Running or running under a load. Just idling at anchor I cannot get the temp gauge to rise. When motoring to the anchorage the water gets real hot.

 

[Bill Roosa]

Half an hour

My 9 gal tank takes at a minimum of half an hour to heat up. Not the super hot it gets after motoring for a while but hot enough to shower or do dishes. I'd guess 120 deg F

 

[timvg]

If you are just idling, it will take a long long time to get hot. Idling at anchor is bad for your engine anyway. Your engine will love you more if you operate it with a load.

 

[shorty]

Our 6 gallon Raritan heats up nice in the time it takes to motor into a harbor to pickup a mooring or set the anchor. Replaced it 3-4 years ago so insulation is new & as such stays hot for breakfast dishes.

 

[Ted]

Is your engine raw water or fresh water cooled? lf it is raw water cooled, your hot water heater will take a long time to heat up and may never get really hot if it is only being heated by your engine. Raw water cooled engines have a lower temperature thermostat (about 140 degrees) that keeps them running cooler than a fresh water cooled engine.