Hot Water Duration
- Thread starter Bob Cat
- Start date
In some of my older boats, the 6 and 10 gallon hot water tanks were insulated enough to keep the water warm for many hours in the summer, but only 2-3 hours in the winter before becoming tepid. The in-cabin location of the water heater in C-Dories ought to be somewhere in between, esp., if the Wallas is used to warm the interior. In many cases, leaving the dock in the am with hot water could still hold tepid water that eve. John
Pat Anderson
New member
I would say 3 - 4 hours is a pretty good time frame. If we heat it in the morning, it is still usually fairly warm at noon. If we heat it in the evening, it is usually only barely warm in the morning if at all. Stuffing insulation in the cabinet would probably help a lot, but we have too much other junk stored in there!
Bob Cat":ct981gpf said:
Pat Anderson":22igkx4e said:
Now, keep in mind where Pat is located... we had to run our Wallas in August up there. :wink:
And that leads me to a question about Pat's comment: can you store "stuff" around the water heater? Is there any problem with stuff being affected by the heater (as in melting)? Is that "cover" that comes on the heater supposed to stay on it? Ours is starting to peel off. Seems too thin to actually be any kind of insulation. Our coaches have always had a LOT of insulation around the outside of the water heater; anyone added any to these? TIA.
Best wishes,
Jim B.
In the RV world (same tanks) wondering about how long it lasts really isn't an issue. Experienced RV'ers know that it never takes longer than 15 minutes to heat a 6 gallon tank, so boondockers never turn them on until they're needed. Really saves on propane as well. The tanks seem to hold useable hot water for about 3-4 hours if yer not in a shower mood.
Sea Skipper
Member
The white "peeling" vinyl is a protective covering to minimize scratching during manufacturing & installation of the water heater. Underneath you will find a beautiful all stainless water heater. You can safely store items next to it as long as they don't block air flow to battery chargers, invertors, or other electronic items mounted near the heater.
My water heater stays hot for at least 16 hours - hot enough that I must use some cold water when taking a shower.
My water heater stays hot for at least 16 hours - hot enough that I must use some cold water when taking a shower.
Sneaks/Don-
I 100% agree with you about RV's and propane fired H-W heaters. but aren't the CD-25/TC-255 units electric, which is why the question was asked?
Sea Skipper-
16 hours! Wow! Did NASA insulate that baby? You sure there isn't a plutonium slug in the bottom of it? Does your hot water glow in the dark?
Joe.
I 100% agree with you about RV's and propane fired H-W heaters. but aren't the CD-25/TC-255 units electric, which is why the question was asked?
Sea Skipper-
16 hours! Wow! Did NASA insulate that baby? You sure there isn't a plutonium slug in the bottom of it? Does your hot water glow in the dark?
Joe.
Sea Skipper
Member
Quote:
16 hours! Wow! Did NASA insulate that baby? You sure there isn't a plutonium slug in the bottom of it? Does your hot water glow in the dark?
Joe.
At the speed I cruise water friction on the hull keeps the tank quite warm!
Seriously - the tank is well insulated between the stainless exterior sheet metal and the internal pressurized tank. If there is an adjustable setting for the electric heater, it seems to be set high.
16 hours! Wow! Did NASA insulate that baby? You sure there isn't a plutonium slug in the bottom of it? Does your hot water glow in the dark?
Joe.
At the speed I cruise water friction on the hull keeps the tank quite warm!
Seriously - the tank is well insulated between the stainless exterior sheet metal and the internal pressurized tank. If there is an adjustable setting for the electric heater, it seems to be set high.
Pat Anderson
New member
The electric hot water heater on Daydream takes about 45 minutes to heat up from cold (Honda 2000i) and, as I say, stays reasonably hot for about four hours. I wonder what hot water heater Hank has on Sea Skipper, I want one like it! I wish Daydream had a propane hot water heater - if we have this boat when the Wallas goes, maybe we'll go propane all around - hot water, cooktop and cabin heat.
Pat, What will really spoil you, if you can get it on the C-Ranger 25, is to run the engine heater water thru the two way (elect/engine) water heater. My last houseboat had that and we had hot water anytime anywhere. I am wondering if you could put a heated water system on boats like they have on motorhomes now, where a remote gas water heater provides hot water that is piped thru the floors, etc. , for heat also. John
Alyssa Jean
New member
Pretty strange diferentials here on 2005 25s. My heater will still have nice warm (100 degree) water in it 12 hours later. I can run the genset at 8-9 pm and have nice warm water in the morning for showering or dishes.
Pat-
If you go propane all round, (I love it), you might look into that Bosch instant hot water system that can make it just behind the tap as fast as you can use it.
Don't know how hard it would be to fit into a CD-25 or CR-25 with it's exhaust requirements, but might well be worth looking into.
***************************************
Sounds like the rest of the CD-25 gang has somewhat varied performance in keeping water hot based on amount of insulation and water temperature setting. The inboard cooling system when you have it offers some "Hot" alternatives, including a cabin heater (Red Dot).
Joe.
If you go propane all round, (I love it), you might look into that Bosch instant hot water system that can make it just behind the tap as fast as you can use it.
Don't know how hard it would be to fit into a CD-25 or CR-25 with it's exhaust requirements, but might well be worth looking into.
***************************************
Sounds like the rest of the CD-25 gang has somewhat varied performance in keeping water hot based on amount of insulation and water temperature setting. The inboard cooling system when you have it offers some "Hot" alternatives, including a cabin heater (Red Dot).
Joe.
Now if my little nephew would hurry up and get his new tug, I could speak first person about the tank. You have to look at the numbers on the small electric flow thru water heaters: at 20 amps you get 17 degrees heat rise at one gallon a minute.
At 29 amps you get 24 degrees heat rise at one gallon a minute. I don't know what you get at 1/2 gallon a minute, but it still seems like even 40 degree temp rise would be (70 to 110) a cool shower! I have seen some small tank units which were 1 or 2 gallon and used 15 to 20 amps, which might be a bit more appropiate for short showers...
I had one of the propane instant flow thru heaters in a boat I bult in the 70's. However there were a number of deaths from carbon monoxide from poorly vented heaters of that type. I decided that the risks were not worth it. Although I have used large bottle LPG for cooking, I have felt that the risks for refigeration and water heating were more than I wanted to assume.
Our experience in larger boats was that if we ran the engine during the previous day, there was water hot enough for shaving and showers in the next morning--however, the water heater was in the engine room, which usually stayed well above ambient temperature, even in Alaska, overnight. (of course at night we had a diesel fired circulating hydronic system for heating the boat--so that also kept the engine room warm--never felt the need to put the heat exchanger of the water heater in the circuit--but it could have been done.)
In the Tom Cat, there is only a small amount of room for extra insullation around the 6 gallon water heater. Based on your various experiences, I probably will go ahead and put in more fiberglass insullation. There is not enough room for other appliances in the compartment with the electric water heater.
At 29 amps you get 24 degrees heat rise at one gallon a minute. I don't know what you get at 1/2 gallon a minute, but it still seems like even 40 degree temp rise would be (70 to 110) a cool shower! I have seen some small tank units which were 1 or 2 gallon and used 15 to 20 amps, which might be a bit more appropiate for short showers...
I had one of the propane instant flow thru heaters in a boat I bult in the 70's. However there were a number of deaths from carbon monoxide from poorly vented heaters of that type. I decided that the risks were not worth it. Although I have used large bottle LPG for cooking, I have felt that the risks for refigeration and water heating were more than I wanted to assume.
Our experience in larger boats was that if we ran the engine during the previous day, there was water hot enough for shaving and showers in the next morning--however, the water heater was in the engine room, which usually stayed well above ambient temperature, even in Alaska, overnight. (of course at night we had a diesel fired circulating hydronic system for heating the boat--so that also kept the engine room warm--never felt the need to put the heat exchanger of the water heater in the circuit--but it could have been done.)
In the Tom Cat, there is only a small amount of room for extra insullation around the 6 gallon water heater. Based on your various experiences, I probably will go ahead and put in more fiberglass insullation. There is not enough room for other appliances in the compartment with the electric water heater.
willhave1day
New member
Not to steal your thread but it kind of is on topic for those wondering water heat options. When we get our boat, I think I will put this on it.
http://www.boatelectric.com/d4wh.htm
5.5lbs (not much heavier than a webasto)
.05gph on low (not much more than a webasto)
1.5A on low (yes, this is twice as much as a webasto)
And use a traditional heat exchanger water heater made for inboards. there are Marine specirfic "radiators" with low amperage fans I'm looking at for cabin heat as well; I can find the link if you're interested. But I figure it would be cheap to fab an automotive heater core in a sheet-metal box with a Granger DC low amp fan. This way everything could be kept in one spot under the stove and have heating ducts for such things as defrost; and run hot water hoses to a separate heat exchanger into the bathroom (no fan of course) like a traditional apartment boiler. If it's warm in there, you won't use as much hot water. I can think of many ways to heat the cabin and berth this way. The total price isn't really much more than a Wallas considering the functionality of it. All in all, I figure 2-3 amp hours (an hour) to run it and fans during the night.
Combined with a small watermaker; we can have alot of hot water for just a couple gallons of diesel over a few days. And we can store the diesel where the black water tank would be; sine we also want an Airhead toilet.
Our plan for the boat is 365 days usable, completely self contained for as long as it takes to need gas for the engines; like putting around the San Juans for a week. Having to find a dock to pump out, or fire up a generator in the wind and rain out back is not our idea of fun . :smiled
The motivation is a spouse who is not happy unless it's 72.45 degrees equally distributed; no hotter, no colder. :roll:
http://www.boatelectric.com/d4wh.htm
5.5lbs (not much heavier than a webasto)
.05gph on low (not much more than a webasto)
1.5A on low (yes, this is twice as much as a webasto)
And use a traditional heat exchanger water heater made for inboards. there are Marine specirfic "radiators" with low amperage fans I'm looking at for cabin heat as well; I can find the link if you're interested. But I figure it would be cheap to fab an automotive heater core in a sheet-metal box with a Granger DC low amp fan. This way everything could be kept in one spot under the stove and have heating ducts for such things as defrost; and run hot water hoses to a separate heat exchanger into the bathroom (no fan of course) like a traditional apartment boiler. If it's warm in there, you won't use as much hot water. I can think of many ways to heat the cabin and berth this way. The total price isn't really much more than a Wallas considering the functionality of it. All in all, I figure 2-3 amp hours (an hour) to run it and fans during the night.
Combined with a small watermaker; we can have alot of hot water for just a couple gallons of diesel over a few days. And we can store the diesel where the black water tank would be; sine we also want an Airhead toilet.
Our plan for the boat is 365 days usable, completely self contained for as long as it takes to need gas for the engines; like putting around the San Juans for a week. Having to find a dock to pump out, or fire up a generator in the wind and rain out back is not our idea of fun . :smiled
The motivation is a spouse who is not happy unless it's 72.45 degrees equally distributed; no hotter, no colder. :roll:
The extra insulation is a must on the water heater. The problem is the tubing connections for the water/water heat exchanger on the back of the unit. Mine were left open, and that allows air to thermo-siphon through the unit and cool it prematurely.
My fix was to cover 4 sides, not bottom or front, with 1" foil-faced rigid foam insulation, taped with foil duct tape. A similar foam box was constructed for the protruding tube fittings on the rear.
With it set up this way, if I leave the dock with hot water in the afternoon, I still have enough for 2 hot showers and breakfast clean-up in the morning.
My fix was to cover 4 sides, not bottom or front, with 1" foil-faced rigid foam insulation, taped with foil duct tape. A similar foam box was constructed for the protruding tube fittings on the rear.
With it set up this way, if I leave the dock with hot water in the afternoon, I still have enough for 2 hot showers and breakfast clean-up in the morning.
Pat Anderson
New member
Brady - this sounds great, probably what I need to do - how about insulating the line from the heater to faucet? So you have the extra insulation on the two sides, back and top. Want to post a few pix?
Minnow":eerip0yl said:
Alyssa Jean
New member
I guess I know what my next project is going to be.