I have a 1993 Cat 30 MKII and it has a heat exchanger that uses the engine cooling/exhaust water to heat the fresh water. While this was a decent enough idea in 1993, between camping and boating, there are way better options today. Has anyone swapped one of these out for something that doesn't require me to run my engine for twenty minutes to have hot water to shower with? I plan to retire to the boat in the spring and would like to update it while it is laid up for the winter.
1993 Catalina 30 water heater replacements?
- Thread starter Mandack
- Start date
Almost all "modern" larger boats have hot water heaters that allow heating with either engine coolant or electrical shore power. So I'm not sure I understand the problem. Just replace your existing one which (probably?) has this same arrangement, with one of those. So you can shower with water heated by electricity at the dock, or at anchor if you've been running the engine.
Antifreeze is circulated through the engine and water heater coils to heat the water. This is a standard way water is heated. If you have shore power connected, you should have heating element in the water heater to heat the water. If your water heater does not have the heating element, you would have to replace the water heater and connect to the electrical wiring with a circuit breaker.
The one alternative is to install a diesel fired hydronic heater which can heat the boat and/or heat the water tank. With this system the HW tank can be heated by the heater, the engine, or electric if the HW tank has the electric option.
Diesel heaters are not an inexpensive option and they do require some decent DIY skills to install.
Diesel heaters are not an inexpensive option and they do require some decent DIY skills to install.
OK, I see replies in the vein of, "This is normal" and "What's the problem, its always been done this way" and "What else is there?". It seems some folks need enlightenment.
I don't know if any of you folks that replied are live aboard folks and, if you are, do you live aboard at a marina? If so, you don't understand the issues faced when living aboard and spending a lot of time anchored in coves and such (like over 60% of the time), and on a mooring the rest (which is almost the same but in a more populated area). This is like boondocking in an RV. No water hookup, no shore power and no easy access to diesel fuel. You have to generate your own power, either through the use of diesel or solar, solve your water supply issue, either through aux tanks to augment your onboard tanks or by making your own via desalination and heat water, again, diesel or electric (diesel powered if you don't have shore power) or by propane.
As you can see, diesel is a common way to do all of these but diesel is a resource that I cannot go to shore in my dinghy and easily obtain. I do not want to carry and haul diesel fuel around by hand for this, it is stupid and unnecessary and dangerous.
It appears from these comments that the boating community is about 20 years behind the RV and Truck Camper community. Both have to solve the same problems as live aboard sailors, they just do it on land.
What else is there? Many new Truck Campers and RVs come with propane fired On Demand units or small 5-6 gallon propane water heaters, like mini home units. Apart from not having to use my diesel engine for everything and use a commodity that is not easily replaceable in the above scenario, I already have propane on board for the stove, oven and grill. 5lb propane tanks are easily transported in a dinghy and safer than hauling a jerry can full of diesel. Propane is better for this purpose in every way than diesel and, apart from the issues already listed, is better for the environment than diesel. Also, nothing ruins a beatiful, peaceful morning like some idiot firing up their engine and scaring away all the wildlife on land and sea and irritating the folks anchored close by.
So I was hoping that someone had switched their old fashioned, "We've always done it this way, why isn't that good enough for you", to something that the rest of folks in the live off the grid community have been doing for years. I'll go look in the RV and Camper forums I guess.
I don't know if any of you folks that replied are live aboard folks and, if you are, do you live aboard at a marina? If so, you don't understand the issues faced when living aboard and spending a lot of time anchored in coves and such (like over 60% of the time), and on a mooring the rest (which is almost the same but in a more populated area). This is like boondocking in an RV. No water hookup, no shore power and no easy access to diesel fuel. You have to generate your own power, either through the use of diesel or solar, solve your water supply issue, either through aux tanks to augment your onboard tanks or by making your own via desalination and heat water, again, diesel or electric (diesel powered if you don't have shore power) or by propane.
As you can see, diesel is a common way to do all of these but diesel is a resource that I cannot go to shore in my dinghy and easily obtain. I do not want to carry and haul diesel fuel around by hand for this, it is stupid and unnecessary and dangerous.
It appears from these comments that the boating community is about 20 years behind the RV and Truck Camper community. Both have to solve the same problems as live aboard sailors, they just do it on land.
What else is there? Many new Truck Campers and RVs come with propane fired On Demand units or small 5-6 gallon propane water heaters, like mini home units. Apart from not having to use my diesel engine for everything and use a commodity that is not easily replaceable in the above scenario, I already have propane on board for the stove, oven and grill. 5lb propane tanks are easily transported in a dinghy and safer than hauling a jerry can full of diesel. Propane is better for this purpose in every way than diesel and, apart from the issues already listed, is better for the environment than diesel. Also, nothing ruins a beatiful, peaceful morning like some idiot firing up their engine and scaring away all the wildlife on land and sea and irritating the folks anchored close by.
So I was hoping that someone had switched their old fashioned, "We've always done it this way, why isn't that good enough for you", to something that the rest of folks in the live off the grid community have been doing for years. I'll go look in the RV and Camper forums I guess.
Some of the members here do have extensive live aboard experience and have replied to this thread and while there are some similarities between the RV world and the Liveaboard world there are some very important distinctions.
In fact, the marine liveaboard world has moved beyond using propane for anything but cooking and even now with affordable LFP batteries and solar, propane is beginning to fall out of favor with liveabroads opting for induction and convection cooking.
For a short while there were on demand propane water heaters for marine use. They are no more. The reason is simple, propane is heavier than air and any leaking propane will settle in the bilge creating an explosion hazard. ABYC standards do not permit propane heaters and water heaters. In an RV any leaking propane will leak to the atmosphere and dissipate and as such it is much safer to use.
Diesel remains popular because it is readily available worldwide and is the most energy dense fuel source suitable for small vessels.
for everything dlochner said. In a marine context propane is significantly more dangerous than diesel, and refilling it is generally less convenient. Propane has been a on boats as cooking fuel, so if it were better for heating water it would’ve been popularized by now. Instead the marine world is moving away from propane in favor of lithium recharged by solar and diesel powered high output alternators.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,074
The query posted about heating water on a 23 ft boat while isolated at anchor for a shower involves both scientific exploration and esthetics. I’ll attempt the scientific method second.
The simple answer based on the implied esthetics is use the sun to heat one of the camp showers found at outdoor stores. Always ready on a sunny day and no fossil fuels needed.
The simple answer based on the implied esthetics is use the sun to heat one of the camp showers found at outdoor stores. Always ready on a sunny day and no fossil fuels needed.
The original poster was asking about heating options for a Catalina 30 . While the solar shower is a great idea ,it's not perfect.
The Pacific Northwest has a great many cloudy days . As with any boat idea , there are too many compromises .
The Pacific Northwest has a great many cloudy days . As with any boat idea , there are too many compromises .
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,074
Always nice to be lectured to about a solution which doesn’t work, isn’t practical, violates standards and is dangerous.
A selection of the relevant ABYC standards are below:
A-26.5.9 Pilot lights and other automatic ignition devices shall be permitted only in appliances with room -sealed
combustion systems
A-26.5.10 Unattended appliances shall incorporate a room -sealed combustion system
A-26.5.12 All appliances shall have flame failure devices on all burners and pilot lights that will prevent gas from flowing to the burner if the flame is not present.
I'm unaware of a propane water heater that meets these standards.
A-26.5.9 Pilot lights and other automatic ignition devices shall be permitted only in appliances with room -sealed
combustion systems
A-26.5.10 Unattended appliances shall incorporate a room -sealed combustion system
A-26.5.12 All appliances shall have flame failure devices on all burners and pilot lights that will prevent gas from flowing to the burner if the flame is not present.
I'm unaware of a propane water heater that meets these standards.
I am not sure that the community has moved beyond it, there is actually a standard for this and it the exact same standard set for having a propane fired cabin heater... and is amazingly similar to the RV industry standard: closed ignition, externally vented intake and exhaust, separate feed line... I have just today spoken to folks who live aboard year round in cold climates using both of these solutions. And there are new power boats coming off the line with propane water heating, not a lot but it is an option that is out there.Always nice to be lectured to about a solution which doesn’t work, isn’t practical, violates standards and is dangerous.
As a person who has lived on boats since I was 7 (coming up on 64 now) and a retired Coast Guardsman who has fought fires at sea, I may be more aware of the potential issues than you may think.
The overall point of my thread was there were potentially better options than wasting diesel fuel to heat water. You say it is readily available and it is but its availability has/had nothing to do with my post. The pain of getting to a place to buy diesel, transporting it by hand and then by dinghy and then pouring it from a jerry can into the fuel fill on a boat at anchor is the biggest concern.
Maybe the answer is something in the vein of a Dometic DC/AC/Propane heater, or just AC/DC. Some folks say that it isn't advisable to use DC as it depletes the battery to fast. That is more of an issue on a straight lead acid battery array than it is on a boat with a large capacity LiFePO4 bank attached to a properly sized solar array.
Last edited:
You are correct, currently there isn't a Marine certified device but there are RV units that meet this standard. I am also looking at DC/AC units as I have a large capacity Lithium array with solar. Thank you for your reply and for remaining helpful and respectful, not everyone does that on a forum.
Another decent option that may work given the areas I am currently in. Thank you for your input!
Thank you for this, I had not heard of this option, I will definitely look into it!
This is why I don't generally post in forums. You could have said nothing or something helpful, as other on this thread have, but you chose to be snarky and disrespectful.Always nice to be lectured to about a solution which doesn’t work, isn’t practical, violates standards and is dangerous.
Keep posting because you got me to be open to a plug and play solution that may be available. A thought came to mind not out of respect but just curiosity. Countless issues of Popular Mechanics through the 50s and beyond and could hardly wait until the next great new invention would actually arrive. Then there was dad sitting in his chair reading the newspaper with the seemingly canned comment 'can't do that not allowed'. Couldn't you just transfer some of the helium out of your flying car into the boat whenever you needed a fill up and do away with all the intermediate vendors? After all I'm sure there's an app for that.