Any ideas about how i can add hot water?

[Uncle G]

We use a 5 litre pressurised spray like MartinR shows.

1 litre of boiling water from the kettle and 3 litres of cold is enough for a good wash.

We keep a 1 litre Thermos flask full of boiled water also - so there's always some hot water available.

[taxwizz]

How about a kettle over an open fire?

[TrentePieds]

Quote: "Electric is still my best option, but the problem is the electric pump."

What do you mean by that? Pumps are no problem. A cheapo Jabsco diaphragm pump will give you constant flow at about 25PSI as long as there is water in the source/tank.

You problem is heating the water in the tank. Go back to Grade X science and recall the "specific heat" of H2O. Rather high! In fact, the very highest of any common substance at 1 calorie per gramme! Ergo you have to put in a LOT of energy to raise the temperature of water one single degree. You can't change that. It's a "law of nature"

"On Demand" heaters are a halffast solution to the straitened economic circumstances that obtained in Europe following WWII. The early ones ran on propane or other bottled gas. Electric ones were developed later. They were never very satisfactory in domestic use. They are less so for use in boats.

The flow rate has to be slow enuff to retain the water in the heating coil long enuff to permit a desired temperature rise (desired output temp - actual input temp). OR the HEAT supplied (= ENERGY supplied) has to be great enuff to achieve that rise at the actual flow rate. It's a balancing act. Therefore people find that their showers are either too cold, or the draw on the propane or electricity is great. Propane can handle it because it is energy dense. Electric "on demand" heaters place EXORBITANT demands on the "energy tank" (the batteries which are anything but energy dense), wherefore to accommodate electrically heated showers you either have to have a huge battery bank or you have to supply the juice by generator. If you have to make juice by burning fuel, why not just use the fuel to heat the water?

Heaters relying on open flame must be installed so they take their combustion air from OUTSIDE the cabin, and so that exhaust funes are led outside, just the same requirements as for an engine. An on-board shower makes a mess of your bilge, though normally the bilge pump will appear to handle the quantity of water. Nothing can help the QUALITY of the water. Fresh water and soap scum is a combination uniquely calculated to make for a stnky bilge and ultimately to set rot in any wood that is there.

Work out an "energy budget" to get a real feel for what I'm talking about.

The garden spryer will turn out to be the simplest solution to your problem if you are in low latitudes. If, as I am, you are in more northerly latitudes, then showers is a hopeless quest in a small boat. But no matter. The answer is a kettle of water heated on the stove, and a "Liverpool wash" And if you are in the Salish Sea - the "Wet Coast"- remember that an even bigger problem in a small boat is to dry the wet towels generated by showering. Doing that can take DAYS!!

TrentePieds

[singlespeed]

Bought a black five gallon garden sprayer a few years ago, ripped out my hot water heater and never looked back. Great for the tropics, but be careful of how long you leave it in the sun, as it can get dangerously hot. I never filled more than four gallons in case I needed to cool the water down. By placing it adjacent to the hatch over the head, I could run the hose into the head and shower inside.

[riki]

Well guys, thanx a lot for your time answering. Indeed a lot of good advice. Look like there are basically to viable options, propane (different opinions about this one, right?) and the black bags and similars. I live in Greece so really the bag could be a viable option, maybe even in winter......but not the "clean" solution that i like though.....but with the space i have and an outboard i think that a fancy hollywood shower will never be an option.
Yes, the sprayer looks not too bad.....will digg a bit on this one.
.....propane boiler......that flame outside the boat is the killer.....

[riki]

Originally Posted by tkeithlu

Or this one. Plugs into a 12v lighter for the pump, your tank for the propane, made for camping.

https://www.amazon.com/Hike-Crew-Por...-1-spons&psc=1

This is a nice piece of hardware......would you feel confortable to use it onboard?

[riki]

Originally Posted by TrentePieds

Quote: "Electric is still my best option, but the problem is the electric pump."

What do you mean by that? Pumps are no problem. A cheapo Jabsco diaphragm pump will give you constant flow at about 25PSI as long as there is water in the source/tank.

The problem with the electric pump is that i have only 150lt fresh water tanks, too small and i will probably get them empty in no time with electrics, this is why i would like to avoid them as hell.

[riki]

Originally Posted by MartinR

A manual garden sprayer. Heat water on your stove, fill the sprayer, pump up the pressure and take the shower.

Somebody sells purpose made for boats. Very easy, doesn't use much water.

Interesting

[geraghtyr]

This might work for you. I've heard of plenty of people doing this for camping.
Budget friendly for sure.

https://www.youtube.com/watch?v=NodTvFcK0Mc

[GinTonic]

Originally Posted by riki

Hi folks.
I would like to have hot water in my only bathroom for shower. Got only manual pums and due to my small water tanks would be wise to keep it this way. Do you have any suggestions about brands/products i can use? Got 1 outboard so engine is not an option.
Cheers

Hi Riki , I have found that the best option for your type of Sailboat is the Excel Tankless On-Demand Gas Water Heater VENTFREE – Propane (LPG) with Low Water Pressure Startup

The Excel Low Pressure Startup unit is outfitted with a magnetic water flow sensor , that allows the unit to work at low water pressure, especially those found in rural areas , RV's and Boats. STARTS WITH 2 PSI


All other tankless gas water heaters rely on the outdated rubber diaphragm scheme , that pushes a pin that actuates a microswitch.


Pressures of the order of 30 psi are needed to move the rubber diaphragm on other older and cheaper units.

THIS ONE IS THE ONLY ONE WITH ODS Vent-Free technology:

ODS is to gas what a circuit breaker is to electricity.

ODS technology originated in Europe, and has been widely used in European gas heating appliances for more than 45 years with an outstanding record of safety and then adopted by U.S. manufacturers for all vent-free gas products such as logsets and camper heaters.

Consumer Product Safety Commission (CPSC) accident/incident data accumulated since 1980 show an unparalleled 100% safety record on ODS-equipped vent-free gas heating appliances. Industry engineers say the ODS pilot is to gas what a circuit breaker is to electricity.

I have seen them on this link:

https://excelonlinestore.com/excel-1...p-ventfree-lpg

[Pegu Club]

as

Originally Posted by MartinR

A manual garden sprayer. Heat water on your stove, fill the sprayer, pump up the pressure and take the shower.

Somebody sells purpose made for boats. Very easy, doesn't use much water.

We have been using one of these for about a year now, I attached a kitchen sink sprayer to it, pump it up and you have a pressure water shower, about one gallon of water per shower, or more if you want to use more water. Works very well, much better than I though it would.

Fair winds,

[riki]

Originally Posted by GinTonic

Hi Riki , I have found that the best option for your type of Sailboat is the Excel Tankless On-Demand Gas Water Heater VENTFREE – Propane (LPG) with Low Water Pressure Startup

Hey Gin, thanx
Nice device but i am afraid that i'll still need to put an electric pump between my tank and the device. But this one looks like can be safely used indoor. Uhm, anothere one to take into consideration.
cheers

[mitiempo]

Unless you use a gravity system such as solar water heated on deck you will need a pump.

One that nobody has mentioned is the Whale DC water heater. It is designed for smaller outboard powered boats. Electrical consumption is 25 amps @ 12 volts.
https://www.whalepumps.com/marine/pr...-Electric-Only

A pressure pump can be bought for less than $100 dollars.

[Splash of Lime]

Originally Posted by riki

Hi folks.
I would like to have hot water in my only bathroom for shower. Got only manual pums and due to my small water tanks would be wise to keep it this way. Do you have any suggestions about brands/products i can use? Got 1 outboard so engine is not an option.
Cheers

Captain Chuck here.

I just had them install an electronic on demand heater I bought at Home Depot. No weight, on demand and works great. Out with the old super heavy water heater and the new one is great, works like a charm and very light weight. Good luck, but I recommend the light weight electric heater on demand.

[TrentePieds]

Quote: "that flame outside the boat is the killer"

The FLAME doesn't have to be outside. Think of this as consisting of three separate, but connected components: 1) the air INTAKE leading from the outside to the heater within the boat, 2) The heater itself where the burner/flame is, and 3) the “chimney” to take the combustion gasses from the heater within the boat to the outside. It is done that way to make absolutely sure that the combustion air/gasses CANNOT mingle with the air you breathe in the cabin.

I would take the advertising spiel regarding the Excel “vent free” heater with huge buckets of salt. Though the “technology" is bruited in the brochure as “new”, it is not. It is nearly 70 years old, but apart from that, the premises are doubtful. In your little catamaran the volume of air in the living space is probably less than 1/10 of the volume of even the smallest shoreside apartment. You can judge for yourself what that will mean for the operation of the Oxygen Deletion Sensor!

But it isn't really depletion of oxygen in you living space you need to worry about – it is increasing levels of Carbon Monoxide deriving from the combustion of the gas. In fact, boats are now required to have CO detectors permanently installed, because CO is odorless and insidious in the extreme. Breathing it unknowingly (unknowingly because it is odourless), you get drowsy, then you fall into a pleasant sleep - and then you never wake up! This is the mechanism people use to commit suicide by leading their car's exhaust into the car itself and just sitting there. Always fatal unless the person is rescued within a very few minutes. Again, to achieve a deadly CO concentration is obviously far easier in the tiny space of your cabin than in even the smallest shoreside apartment. That is why an open flame heater in a boat must be vented to the outside!

I quote from the pamphlet: “Pure Oxygen Free Copper has many desirable properties” What, pray, is “Pure Oxygen Free Copper”? Copper IS, as a metal, “oxygen free”! That is not a characteristic of some magic, special, superior kind of copper! Copper Oxide is normally the functional equivalent of rust on iron. Not something you wan't on your heating coils, so obviously ALL heaters have "oxygen free" heating coils.

All that is contained in this pamphlet is, IMO, mere marketing fluff. As I said, take the hype with great buckets of salt!

Surveyors would not likely give a clear survey to a boat fitted with one of these, and that has implications for obtaining insurance coverage. So look before you leap :-)

TP