1993 Catalina 30 water heater replacements?

[Don S/V ILLusion]

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.

I think I know why you feel that way. Like most people, I found your lecture both offensive and condescending.
When you “talk down” to people you don’t know, many of whom have a vast knowledge of the topic, you might not act so surprised by the response.
Regardless, hope you find the panacea you seek.

 

[dLj]

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.

@Mandack So with all due respect, I've been watching this thread with some minor interest as I may potentially be looking, in the not distant future, to change my hot water system on my boat. Then I begin to see back and forth's about snarky replies and I was a bit confused as I was just watching from a distance so to speak and not paying close attention.... So I went back to the very first post and began reading the posts in order - the above included post is from you. And one I would consider pretty snarky. It is the first snarky post in this thread. So, again with all due respect, you brought the snarky replies on yourself by initiating that whole scenario.

I don't know how long you've been on this forum, but the folks posting above this post of yours were simply asking questions given your initial post was rather unclear. Just an observation. And feel free to give me as snarky a reply as you wish. I have pretty thick skin....

As to water heaters on boats - since I'm of the belief that a post should contain information useful to the greater community - while in some areas looking into what the RV world does can be useful, one does have to be cautious of where it can and cannot apply. A previous post did that well talking about the difference between propane on a RV and in a boat. In my opinion, I would never use propane for a hot water heater on a boat for additional reasons beyond that already mentioned. Propane storage on a boat is a concern, and having enough just for a stove keeps me pretty much maxed out on planning for that. You mentioned not being easily able to get diesel, getting propane is as difficult if not more difficult. Using propane to heat water would greatly increase the amount of propane needed on the boat. I don't know what you use for a stove, but as mine is propane, I know I couldn't possibly carry enough additional propane to handle heating water.

Heating water has a large energy requirement. Most common hot water heaters on boats used engine heat and shore power, you can use either when using the boat. My hot water tank is similar, and because of the energy required to heat water, my electrical element cannot be run off my house batteries - it can only be run off shore power or if I wish to run a generator (same thing really). So for long distance or remote cruising, I rely on heating the water through using my engine. On long trips, I don't bother with hot water. I use the ocean and rinse afterwards with whatever temperature water comes out of my cockpit shower at the time. If I were sailing in higher latitudes, I might want to change that. I am very interested in learning about other ways to make hot water.

dj

 

[dlochner]

I am very interested in learning about other ways to make hot water.

Second Star has a 6 gallon Raritan HW tank which can heat water through electricity (120vac, 12a) or from hot water from the hydronic heating system.

Water for the hydronic heating system can be heated one of two ways, through a small diesel heater (Webasto TSL17) or from the engine. The HW tank has an aqua stat that will call from heat if the tank temp goes below 100°F. If if the system is set to engine heat, then the circulation pump starts. If the system is set to run the heater then the heater ignites and runs until the water temp reaches 125°. To keep the cabin from becoming a sauna in warm weather the fan units, which pump warm air into the cabin, have a hi/lo/off switch. There is a little heat emitted from the fan units and hoses when the fan is off, but not much and it helps to dry some the lockers in which the hoses and fan units are located.

When we're motoring a lot, like on the ICW, the engine heat keeps everything warm, when it is cold and the heater is running, the HW tank acts as a reservoir of warm water which speeds up the time it takes for the fan units to reach operating temperature.

 

[dLj]

Second Star has a 6 gallon Raritan HW tank which can heat water through electricity (120vac, 12a) or from hot water from the hydronic heating system.

That sounds pretty much spot on for my hot water heater also, that's 1440 watts of energy - as I have a 2 KW inverter, I felt it was too close to max output on my inverter to run my hot water tank through that inverter so I pulled it out of the 120V AC system that runs out of my inverter - it originally was wired to be able to run off my inverter. I could just see myself not realizing the hot water tank was pulling power to heat water while I plugged in a power tool, causing too much power getting pulled through my inverter and blowing it. Now that would be an expensive "oh sh!t"....

Water for the hydronic heating system can be heated one of two ways, through a small diesel heater (Webasto TSL17) or from the engine. The HW tank has an aqua stat that will call from heat if the tank temp goes below 100°F. If if the system is set to engine heat, then the circulation pump starts. If the system is set to run the heater then the heater ignites and runs until the water temp reaches 125°. To keep the cabin from becoming a sauna in warm weather the fan units, which pump warm air into the cabin, have a hi/lo/off switch. There is a little heat emitted from the fan units and hoses when the fan is off, but not much and it helps to dry some the lockers in which the hoses and fan units are located.

When we're motoring a lot, like on the ICW, the engine heat keeps everything warm, when it is cold and the heater is running, the HW tank acts as a reservoir of warm water which speeds up the time it takes for the fan units to reach operating temperature.

I'll have to look at the Webasto TSL17. I've been thinking of getting rid of my heat pump and putting in a diesel heater. But I'm not sure what then to do for AC..... My current heat pump will both heat and cool. I have forced air throughout the boat which is a nice benefit. AC is another high energy system that I haven't come fully to grips with yet... I did the same thing with the wiring on my heat pump. I don't recall exactly, but I think it's about 1800 watts so also very close to max capacity on my inverter... in the tropics, there are times when it's really nice to have a bit of AC available...

Does your system require you to select what heat source is being used to generate hot water? I'd love to see a circuit/plumbing diagram of your setup. You have to have an external vent on that Webasto, no? Do you go through your coach roof?

dj

 

[Tally Ho]

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.

Most have an electric element in addition to the engine coolant system. So, if you are living aboard with shore power, you just use the electric element.

Greg

 

[dlochner]

Does your system require you to select what heat source is being used to generate hot water? I'd love to see a circuit/plumbing diagram of your setup. You have to have an external vent on that Webasto, no? Do you go through your coach roof?

Dave, attached is a simplified drawing of the heating system. The Summer Valve is a by pass valve so heating fluid does not go to the fans. I didn't install one because I was running out of space and I decided that warming the nooks and crannies where the heating loop went wasn't a big deal and I could shut off the fans.

I purchased most of the system from Sure Marine in Seattle. They have a proprietary SureWire panel that makes the electrical side of the system very easy to install and allows for the flexibility that I wanted. The presale and installation support was good. Post installation support was not that strong until the President of the company got involved and then it was excellent. The problem I had was a mistake I made, 5/16" has a a larger ID than 5/16" tubing. Learn something new every day. And a faulty SureWire panel. The whole support process was complicated by us cruising in Canada and shipping delays.

We spent a lot of time motoring and the system worked great. Our Raritan HW tank is well insulated and water will stay hot for at least a day. While motoring we'd run the heater off engine heat and get the cabin really warm, up into the 70s. By morning the temp would be in the low 60s which was tolerable and helped to get us moving.

There are Chinese knock offs that are much less expensive than the Webasto, however, you're pretty much on your own for installation support and instruction. That support and the SureWire panel was worth the extra money. By the time I was done I had run about 300' of wire. Simpler systems are possible, but not as flexible or cool.

Be glad to answer any questions.

 

[dLj]

Dave, attached is a simplified drawing of the heating system. The Summer Valve is a by pass valve so heating fluid does not go to the fans. I didn't install one because I was running out of space and I decided that warming the nooks and crannies where the heating loop went wasn't a big deal and I could shut off the fans.

I purchased most of the system from Sure Marine in Seattle. They have a proprietary SureWire panel that makes the electrical side of the system very easy to install and allows for the flexibility that I wanted. The presale and installation support was good. Post installation support was not that strong until the President of the company got involved and then it was excellent. The problem I had was a mistake I made, 5/16" has a a larger ID than 5/16" tubing. Learn something new every day. And a faulty SureWire panel. The whole support process was complicated by us cruising in Canada and shipping delays.

We spent a lot of time motoring and the system worked great. Our Raritan HW tank is well insulated and water will stay hot for at least a day. While motoring we'd run the heater off engine heat and get the cabin really warm, up into the 70s. By morning the temp would be in the low 60s which was tolerable and helped to get us moving.

There are Chinese knock offs that are much less expensive than the Webasto, however, you're pretty much on your own for installation support and instruction. That support and the SureWire panel was worth the extra money. By the time I was done I had run about 300' of wire. Simpler systems are possible, but not as flexible or cool.

Be glad to answer any questions.

@dlochner Looking over your schematic, I have a several questions.

Are you heating your boat by transporting hot water to heat exchangers that then heat the boat how, by hot water radiators? By forced hot air?

What are the two heaters, the 6200B and the 6000B? You have the hot water coming out of the hot water tank going into these two, and the summer valve which appears to bypass those two heaters for "summer" use. Are these just heat exchangers using the hot water to heat the cabin? Are they located in different locations of the boat for heat distribution? This is probably related to my first question above.
What is the HX? Is this a separate tank? It looks like I would then take the hot water from the engine and use it to heat the water in the system feeding the hot water tank. Essentially, that is my current hot water tank.

I don't see any connection to the SureWire panel.

I'm digesting your diagram...

dj

I'm guessing you did not include the fresh water system connection for domestic use on this diagram.

What's the function of the U4840 pump?

 

[dlochner]

@dlochner Looking over your schematic, I have a several questions.

Are you heating your boat by transporting hot water to heat exchangers that then heat the boat how, by hot water radiators? By forced hot air?

What are the two heaters, the 6200B and the 6000B? You have the hot water coming out of the hot water tank going into these two, and the summer valve which appears to bypass those two heaters for "summer" use. Are these just heat exchangers using the hot water to heat the cabin? Are they located in different locations of the boat for heat distribution? This is probably related to my first question above.
What is the HX? Is this a separate tank? It looks like I would then take the hot water from the engine and use it to heat the water in the system feeding the hot water tank. Essentially, that is my current hot water tank.

I don't see any connection to the SureWire panel.

I'm digesting your diagram...

dj

I'm guessing you did not include the fresh water system connection for domestic use on this diagram.

What's the function of the U4840 pump?

A little wasabi sauce goes well with the diagram.

The 2 Fan units are small radiators with a computer fan. The fans moves air across the radiator and warms it. The fans are controlled by a thermostat at the fan, when the water heats to 125° F the fans come on. The smaller fan is in the V-berth and larger fan is in the main salon.

The U480 pump is the circulation pump, it moves the heating fluid through the system. It's a vane pump and is not self-priming so it needs some head. This is why it is at the end of the system. The expansion tank is higher than the pumps it provides head.

The pump pushes heating fluid (proprolyne glycol) through the heater, then on to the heat exchanger, through the HW tank and on to the 2 fan units before entering the expansion tank and then back to the pump. This happens regardless of the heat source.

The heat source is controlled by an on-off-on switch. One on position is heater, the other is for engine heat.

If the switch is set to use the heater, the heater comes on and heats the water before it flows through the system. This will occur even when the motor is running, unless the switch is set to off or engine heat.

If the switch is set to engine heat, the pump circulates the heating fluid and the heater does not run. The heating fluid is heated by going through the heat exchanger. Engine coolant always circulates through the heat exchanger regardless of the heating system's mode.

The heat exchanger heats the heating fluid from the engine. They are 2 separate systems. The engine coolant and the heating fluid never mix, they are separate systems. See the attached photo, the engine coolant enters the bottom of the heat exchanger while the heating fluid goes through horizontally. As a result it gets warm regardless of whether the heating system is calling for heat or not. In my case, this is both a benefit and a deficit. After motoring for a long while (a not so popular pastime on the ICW) the hot water lines get warm, this reduces the amount of water that must be drained to get hot water. On the other hand, all this and the batteries are in the same compartment, the LFPs aren't all that happen in the summer with the extra heat.

The parts and pieces, clockwise from the upper left: large fan unit, Webasto heater, expansion tank, ciruclation pump, exhaust drain fuel pump, expansion tank, overflow tank, muffler, heat exchanger, fan and heater switches, small fan unit, thermostat, and in the center is the SureWire panel where all the electrical connections are made.

A whole mess of stuff here. The black tube is the HX, the orange PEX on the left is the heater feed, the reddish hoses on the right go to the HW tank and then on to the rest of the system. The black hoses are from the engine.

 

[Hayden Watson]

I built a hydronic system into my 1988 C30 Mk2 back in 2017 and it has performed fantastically. Mine also uses the Real fan coils that @dlochner has in his system but I used the Espar S3 D5E for my boiler. I upgraded all of the fans in the fan coils to PWM controlled case fan with much greater max airflow but with the ability to run slow and silent when I do not need that much heat. Here is a line drawing of my system.

 

[dLj]

OK, so sometimes I can be a little dense... You have both run heating throughout your boats by piping water (water/antifreeze) throughout strategic locations for heat exchangers to heat the boat, including the hot water for the hot water tank. I already have a forced air system with both AC and heat. And I have a separate system just for my hot water tank.

With a hydronic system, that includes the hot water tank, you can't run AC. I can see running a hydronic system that also does AC but not if it includes the hot water tank for domestic hot water. There are residential systems that do that. But you need two separate systems, one for heat and AC, and one for hot water. Therein lies my current dilemma.

I'm looking for a more efficient way to heat my hot water while running under strictly 12V and then to have a system that gives me both heat and AC through my forced air ducted system. The hot water electric unit runs 120V AC and has a significant electrical consumption. Once I get my hot water heated through my engine, it would not be overly difficult, seems to me, to maintain that hot water via a 12V "booster" perhaps or something like that. My current heat pump, which drives my hot air or cooled air for AC also consumes a lot of power. I'm looking for a system that can do a similar function but consumes a lot less power. But I've found nothing that seems appropriate. I'd be happy if I found a system that provided good heat, and at least some AC that could work. I find it easier to deal with heat than cold. For heat, I can run very low power fans and if I had a small boost to that system, I'd be fine.

dj

 

[TimFromLI]

This thread has drifted way from the OP's original post. All great ideas but if anyone knows of a safe on demand hot water heater I would be interesed. My wife and I like to cruise and the hot water only lasts a day or so before I need to run the engine. As the OP or someone said earlier, there are some creative LP on demand hot water heaters for RV's, why not boats?

 

[jssailem]

there are some creative LP on demand hot water heaters for RV's, why not boats?

I take a SWAG at this.
RV's being land based provide a methodology for the occupant to escape from the proximity of the danger associated with a fire condition or gas leak condition. Alarms sound and the occupants flee from the vehicle, moving to a safe distance from the event.

This is not the case on a boat. The boat is the place of safety, not a park bench 100 yards from the RV.

Maybe creative minds will develop systems that can make such devices safe for water craft. Will they be designed to fit in the space of a 30ft sailing vessel? Time will tell. I suspect there will be innovators testing the current boundaries. Money and compromises by the owners of boats will factor in to such ideas.

 

[dLj]

This thread has drifted way from the OP's original post. All great ideas but if anyone knows of a safe on demand hot water heater I would be interesed. My wife and I like to cruise and the hot water only lasts a day or so before I need to run the engine. As the OP or someone said earlier, there are some creative LP on demand hot water heaters for RV's, why not boats?

The answer for not using LP for a water heater on a boat has been pretty well covered in this thread. It's inherently more dangerous than in an RV along with some other concerns.

On demand hot water is not something I've looked into for my boat so don't really know what's out there. Thinking about it, I would guess for a boat you would have only two really viable energy sources for on demand - electric or diesel. But I haven't researched it.

dj

 

[Davidasailor26]

RV's being land based provide a methodology for the occupant to escape from the proximity of the danger associated with a fire condition or gas leak condition. Alarms sound and the occupants flee from the vehicle, moving to a safe distance from the event.

This is not the case on a boat. The boat is the place of safety, not a park bench 100 yards from the RV.

I think that’s part of it, but there’s also more places to safely ventilate propane on an RV compared to a boat. On an RV you can have a lot of the propane plumbing run through places where heavy vapors can drain down and then dissipate over the ground. On a boat a lot of the plumbing needs to run in places that can only possibly drain to the bilge, below the waterline with nowhere to escape.

 

[dlochner]

In the last 50 year of recreational boating lots of ideas have been tried and discarded, including heating, cooling, and heating hot water. We've tried various forms of diesel and kerosene heating and lighting, we've tried CNG, pressurized alcohol, unpressurized alcohol along with diesel and kerosene and none of them have panned out, and we have tried propane on-demand hot water tanks, and that has gone by the wayside.

The reasons for their passing into oblivion vary, from smelly and sooty kerosene and diesel devices, to safety for propane how water heaters, to inconvenience and safety for CNG stoves. The other factor is the market. The cruising/liveaboard sailboat market just isn't large enough to support development of safe propane heating devices other than stoves. I find it difficult to believe that any company would see this as a viable profitable venture.

The other issue with HW is that heating water is hard and consumes a lot of energy. Thus it needs a good energy source such as the electrical grid or waste heat from a diesel engine or a small diesel boiler like the Espar or Webasto. For boats diesel is the most energy dense fuel, even better than solar. I would take a lot of solar to heat 6 gallons of water. A Raritan HW tank with a 1250 watt element has a recovery rate of 13 gallons per hour. Heating the 6 gallon tank, pretty common in our boats, would consume 625 watt hours of electricity at 120 vac or about 54 amp hours of DC not counting efficient lost to the inverter. In perspective a Group 31 AGM or LA battery has about 100 ah of which only 50 ah is available for use. A boat would need a pretty large battery bank to make this work.

Until someone invents some new efficient form heating water on a boat we're just going to have to live with cold showers or live at a dock.

 

[dLj]

In the last 50 year of recreational boating lots of ideas have been tried and discarded, including heating, cooling, and heating hot water. We've tried various forms of diesel and kerosene heating and lighting, we've tried CNG, pressurized alcohol, unpressurized alcohol along with diesel and kerosene and none of them have panned out, and we have tried propane on-demand hot water tanks, and that has gone by the wayside.

The reasons for their passing into oblivion vary, from smelly and sooty kerosene and diesel devices, to safety for propane how water heaters, to inconvenience and safety for CNG stoves. The other factor is the market. The cruising/liveaboard sailboat market just isn't large enough to support development of safe propane heating devices other than stoves. I find it difficult to believe that any company would see this as a viable profitable venture.

The other issue with HW is that heating water is hard and consumes a lot of energy. Thus it needs a good energy source such as the electrical grid or waste heat from a diesel engine or a small diesel boiler like the Espar or Webasto. For boats diesel is the most energy dense fuel, even better than solar. I would take a lot of solar to heat 6 gallons of water. A Raritan HW tank with a 1250 watt element has a recovery rate of 13 gallons per hour. Heating the 6 gallon tank, pretty common in our boats, would consume 625 watt hours of electricity at 120 vac or about 54 amp hours of DC not counting efficient lost to the inverter. In perspective a Group 31 AGM or LA battery has about 100 ah of which only 50 ah is available for use. A boat would need a pretty large battery bank to make this work.

Until someone invents some new efficient form heating water on a boat we're just going to have to live with cold showers or live at a dock.

Pretty good summary. the only fuel source you mention I've not used is CNG. You didn't mention solar ovens, something else I've also used. They seem to work best at anchor and in the regions with lots of sun - the Pacific Northwest probably is not going to have great success with that... There's quite a learning curve with that one...

I can't see how on-demand hot water can work on a boat - possibly with diesel, but nobody is going to develop that. The market would be almost non-existent. I've used the black bag, gravity feed, shower source - that actually works pretty well - but it's most certainly not "on-demand".... Add a simple hand pumped pressure tank and those are quite nice. But they are really for being out in the wild (I have seen folks put up shower curtains but I've not done that) as taking a shower out on deck naked is not looked upon as socially acceptable...

There have been some excellent improvements in diesel stoves and heaters - I recall an early diesel stove I owned on one boat - there was always the smell of diesel in the boat and a black swath above the stove no matter how well one figured out how to run it... Both have come a long way now. Alluring Artic did a YouTube video on heaters for cold weather - it's excellent if anyone is interested in looking at it. The hydronic system you have is a good way to retrofit a boat with no heat as it's pretty hard to run duct work for hot air - but hot air is the fastest to heat up a boat. Since I have all the heat ducts already installed in my boat, I'm more looking at how best to utilize this system.

I've been thinking about a 12V heater element that I can modify to fit my hot water tank and have a switch to run it. I would not want it to be "automatic" - I'd need my solar panel kicking out plenty of power to run it. Or the automatic logic would have to be fairly sophisticated and I'm not a major fan of sophisticated electrical systems on boats. But it's still down the road. My first major work in those lines will be figuring out my heat/AC system for my forced air system. I really hate my current heat pump... It works when it's not very cold or not very hot. But sucks outside that range.

dj

 

[dlochner]

I've been thinking about a 12V heater element that I can modify to fit my hot water tank and have a switch to run it. I would not want it to be "automatic" - I'd need my solar panel kicking out plenty of power to run it. Or the automatic logic would have to be fairly sophisticated and I'm not a major fan of sophisticated electrical systems on boats. But it's still down the road. My first major work in those lines will be figuring out my heat/AC system for my forced air system. I really hate my current heat pump... It works when it's not very cold or not very hot. But sucks outside that range.

Nice heat pump, works exactly when you don't really need it.

Victron controllers have 2 out puts, one for the battery and one for load. The thinking is when there is excesses solar power that power that extra is dumped into something else, like a how water tank. You'd need a lot of solar to rely on that to heat water, but, from time to time it might provide enough to preheat water or keep warm water warm. It works best with LA batteries, because their capacity to absorb amps goes down when their SOC rises. That extra capacity would then be diverted to the heater.

 

[dLj]

Nice heat pump, works exactly when you don't really need it.

Indeed - rather disappointing...

Victron controllers have 2 out puts, one for the battery and one for load. The thinking is when there is excesses solar power that power that extra is dumped into something else, like a how water tank. You'd need a lot of solar to rely on that to heat water, but, from time to time it might provide enough to preheat water or keep warm water warm. It works best with LA batteries, because their capacity to absorb amps goes down when their SOC rises. That extra capacity would then be diverted to the heater.

I have LiFePo house batteries. Not likely going to work for me.

I am thinking about mostly about keeping the water warm once heated by the engine. My tank keeps water nicely warm for about 2 days once heated. But it's a project down the road. Improving my heat pump system is higher on the list. Black bag shower option works just fine for now....
dj

 

[Hayden Watson]

With my hydronic system, I run the heater boiler for one hour each morning which dries out any condensation that accumulated over night and heats the hot water tank which then stays nicely hot enough to do the dinner dishes. It burns 0.15 gal/hour [0.59 l/hr] for the first 5 minutes and then drops down to the lowest burn setting which only draws 0.04 gal per hour [0.15 l/hr]. During that time, It consumes about 8 Ah of my 560Ah battery.

 

[jssailem]

Diesel is on the boat and produces more BTU’s per unit (gal, liters, or pounds) than Propane. This suggests the more efficient and safe model would be to heat water as @Hayden Watson does with his hydronic system.