Hot water temperature

baz

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Jun 19, 2009
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Fluid Motion Model
C-24 C
For R-25's hot water supply what is its highest temperature and can it be controlled (lowered and raised). If water temperature can be adjusted how is that done? Thanks... 🙂
 
Great Question! Never even thought of it 😳 I find that the hot water tank is plenty hot and you have good control from the faucets. The other question I would have would is whether increasing the temp will actually increase the power usage and when your out...may burn through your batts alot sooner.

Drew
 
Good question - I've never seen a place for adjustments. For us, we mostly let the engine do the heating...I'm guessing it gets as hot as the engine cooling water - is that possible? I know our hot water is very, very hot...

When plugged into shore power, you can heat the hot water as well. Can't do it off the batteries....

Mac
 
One consideration left out is that water heater uses engine reject heat from engine coolant. If you oberate the main engine you heat the water in water heater without turning on 120 volt breaker. i discovered this by accident one day when I found that the water was hot when I knew I had not had heater on for weeks.
 
The electric water heaters I've seen on boats didn't have adjustable thermostats, but did have safety valves to prevent over pressure. I'd venture to guess the heating element has a thermostat to keep the temp down. The engine heated water can reach temps in the 170-180 degree F. range. I've never come across a mixer valve for cooling it. So, I'd guess the water can reach that temperature in the tank.

What's well above house heaters, approx. 135 degrees F.

Gene
 
I agree with rt11002003. There is usually a set thermostat in marine water heaters, I have repaired a few and found this to be the case. They are usually a little higher then home water heaters. I think it is because boats usually have smaller hot water tanks so a little bit of really hot water with a bunch of cold can make for a nice, warm shower.
 
baz":39i5h9ox said:
For R-25's hot water supply what is its highest temperature and can it be controlled (lowered and raised). If water temperature can be adjusted how is that done? Thanks... 🙂

Running off the generator or shore power, the heater's thermostat is not adjustable, as mentioned above.

When running the main engine, coolant circulates through the water heater and on up to the cabin heater before returning to the engine. That coolant is up to 180 degrees, enough to cause a really bad burn very quickly. If you have been running your engine for a while, the whole hot water tank can reach those temperatures, so be very careful about using any part of your body to test how hot it is. Hot enough to blister you is the answer. (Another entry from the large file of things I shouldn't know, but do...)
 
I do know that the water in the water heater was still very warm 3 days after I returned from a week long underway period with the 120 volt breaker off the entire period. Water heater either was very hot or very well insulated.
 
Both.

Water temp from engine operations was about 170 to 180 degrees. The hot water tanks I've been exposed to kept the water warm for two to three days whether from the engine heat or the 110 volt heater. Of course I'm talking about in warm weather. In the winter, in North Alabama, the water was warm the following day.

Gene
 
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