Opinion on diesel heaters

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Andy G

Hospitality Officer
Joined
Sep 20, 2010
Messages
1,902
Location
Australia
Vessel Name
Sarawana
Vessel Make
IG 36 Quad Cabin
I have been thinking about installing a diesel heater for the cabin and berths. Not sure about the pro's and con's of an aftermarket instillation.

Anyone gone down this path?
 
While I have a hydronic system, it guzzles fuel, even in mild weather. So I installed a couple Chinese diesel heaters from ebay in opposite ends of my main deck cabin. Not too difficult.

On Youtube John McK 47 has several videos on the heaters along with showing what's inside.
 
Cant speak highly enough of the Wallas Spartan heating units. They sip miniscule amounts of fuel and keep our boat nice and toasty on land, in 0 degree F weather with the wind whipping!

https://scanmarineusa.com/products/heaters/
 
Wallas for me, but pricey.


Kevin Sanders is another fan with thousands of hours on his (many thousands).


I have around 3000 on mine and even when it wouldn't start, I could always get it to.
 
I installed an Espar D2 heater in a Sprinter van 5 years ago. I have 1200 hours run time on it, and it's great. Uses a small amount of fuel, and keeps a van warm despite -5 deg F outside air temps.

Espar heaters are not inexpensive, and they are somewhat complicated, but once you sit down and lay everything out, the install is not too bad. Many, many #vanlifers use Espar heaters.
 
Wallas owners all seem to like them. I have Espar hydronic, like Doc above. I installed it in the boat 10 years ago, and it has run well after I gave it a dedicated fuel tank that gravity-feeds. Still, in retrospect, I probably wouldn't buy Espar again because there is no local support for it, compared to Wabasto or Wallas. I'd recommend that whatever system you choose have parts and service available where you live. That was an error on my part when I chose which system to install.
 
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I have three Wallas units on my boat for a total of 30,000 BTU of capacity.

I have been heating my boat full time in Seward Alaska since 2012. One heater I sent in for service had 27,000 hours on it, and it is still in service.

What I have found is that the furnaces are quiet, very reliable, and the company has made continuous improvements to the product as technology progresses.

The current generation of furnaces the Spartan series has bluetooth, and internet connectivity. The tech support folks can access your furnace and look at historical logs, etc.. to help diagnose a problem. You as the oewner have full remote control so you never arrive to a cold boat.

This spring i had a furnace shutting down. Of course I blamed the heater and emailed the folks at SCAN marine in seattle.

Within hours on a weekend they had sent me the historical log, and had told me that they thought the furnace was experiencing a collapsing fuel line.

They were right and I was back up and running using in this case the recommended rigid plastic fuel line that they supply, which was NOT installed when I had a shipyard install the furnace in 2012 as part of a major refit.

Based on their fantastic tech support and reliability I whole heartedly recommend Wallas and Scan Marine.
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Just finished removing an espar and replacing it with the espar D8...Cliffv marine in Seattle provided all kind of help and product. It was mostly plug and play...put all the pieces together...and hot (200f) dry air in no time. Parts and furnace...$3200...totally satisfied
 
It depends on the depth of your pocket and if your a gadget guy.
Me I like things KISS.
I had a 3 kw Webasto on the boat when I bought it and it was 'temperamental'. I like things to work properly when they're supposed to, you hit a point of BER (beyond economical repair) where you're spending more money on repairs than the cost of a new one.
I try not to support China if I possibly can avoid it and buy Western made goods but I don't like getting ripped off for a particular make/model which is 'Made in China' and rebadged while some middle man/company has a nice office and expense account at my expense. (Jabsco's one of them)
I bought a 5kw cheap Chinese heater from Wish.com and it worked kinda (they always exaggerate the output) so I sold it to a guy with a smaller boat and bought an 8kw one.
Its working perfectly for £220 delivered.
The Chinese heaters are a knockoff of the Russian 'Planar' heaters, but do get one that can blow cold air to act as a a cheapo cooler in the summer.
The best thing I did was to insulate all the pipes and fit simple hand operated regulated outlets in each cabin and that helped to boost delivered hot air by about 20% (the insulation cost more than the heater).
You pays your money and makes your choice.
 
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On top of any other advantages, I would place a high value on the much quieter exhaust of the Wallas vs. the Espar/Webasto/parking type heater.

Nice quiet anchorage of a morning (or evening), and I know I'd be reluctant to fire one of the latter up (Roar!).

If that's something that matters to you, it might be a plus for one of the Wallas heater models.
 
I bought the Russian Planar heater back in 2015, when the Chinese knock-offs weren't really as readily available.

It's been fine. I guess some people are bothered by HVAC system noise more than I. My central air conditioner at home is on right now, and I think it's louder sitting here at my desk than the Planar is when I'm lying in my berth on the boat. Obviously, YMMV.

Doing it again today, I'd buy two Chinese knock-offs; one to install and one spare. That's still cheaper than the Planar, and a LOT cheaper than the big name brands.

To me the biggest negative is the exhaust pipe. These things were designed to be used in trucks, where the exhaust goes directly down just a few inches. On a boat, you may need to route the exhaust much too close to fiberglass or wood. I've seen these pipes glow cherry-red. If I did this again, I'd make sure to locate the heater as close as possible to the exhaust port. You also want to be sure to minimize any restrictions to air flow. You need to consider combustion air flow and exhaust flow, as well as both intake and distribution of the heated air. Minimize duct lengths and bends. These things will overheat if they don't get enough flow in any of these places.
 
Have had various drip, air Espar and diesel Webasto hydronic. The Webasto was by far and away the best of the lot. Would say it’s worth figuring out a way to block the furnace exhaust if it’s not going to be in use for awhile. Even an oily rag or tape. The nozzle will corrode and even with their tool is a pain to replace. Also never let the coolant run low. Bleeding air is a pain as well.
However, if it was retrofitting unless I was fortunate enough to have a very large boat would put in a danish Refleks. They make a unit that can fit into a convenient locker and their other units are jewelry. Main purchasers are commercial fish boats around here and they have a rep of needing very rare attention. You can add hydronic zones to the main unit. Also capture engine waste heat as well as heat domestic water if you want.
 
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I think I say this on every heater thread...

Be sure you understand your policy. Many require certified heaters. I have a Dickinson stove, which I wouldn't recommend to most people, as it is pretty old-school. If I do install a diesel heater, it will be a Wallas
 
If you check them out you will find that most are supplied with silencers for the exhaust. As Capt Tom says, when you install them use top class insulation both on the exhaust and the ducting and they are fine.
 
I have been thinking about installing a diesel heater for the cabin and berths. Not sure about the pro's and con's of an aftermarket instillation.

Anyone gone down this path?

Hi Andy G. There's lots of aspects of diesel heat way beyond the brand of heater you should chose. Personally, here in the PNW, I would not be without one. Even though each of my multiplicity of boats ALSO had electric radiant heaters, various portable catalytic and/or oil heaters, engine block heaters, reverse-cycle, and a plethora of other heating systems aboard.

And given one of my past boats included a non-OEM installation of a fan forced-air diesel heating system, the main issue with the install was not the choice of heater, the politics of the country of origin of the heating unit, the location of the heating element, the fuel plumbing, the location of the heater's exhaust, or the multiple other compromises a non-OEM installation of any forced-air heating system brings. The main issue was the ability of the installer to snake the ducting from the heater itself throughout the boat to maximize the heat transfer from the heater to the occupants. No matter where they happened to be at the time.

And THAT can of worms involved ducts passed through cabinetry in places that compromised the cabinet's use that would have been obviated had the ducting been installed with foreknowledge of the cabinet maker and/or the naval architect. And ductwork passed (in my case, anyway) throughout the overhead in the engine room, and in other places where it was simply an eyesore and very much in the way.

And despite these compromises, the fan forced-air diesel heater was my absolutely go-to 1st choice for heat, either underway or at anchor. And always there as a standby when the reverse-cycle system (which was OEM, but noisy and kinda puny) wasn't so useful when trying to sleep. Had I actually been involved in the post-build of the heater, I might well have spent the rather large up-charge to install a hydronic unit, given it's miles easier to move warm water than warm air around a boat.

And lastly, as I have no idea where you are located, what your boating circumstances are, your personal proclivities concerning comfort, nor a whit about an IG 36, any input from me is somewhat speculative. But I guess I'd part with a suggestion you think long and hard about how you get warm air from a diesel heater distributed about your boat before you get bogged down trying to pick the pepper from the fly poop about what brand of heater is in your best interest. I have absolutely no idea!

Regards,

Pete
 
II guess some people are bothered by HVAC system noise more than I. My central air conditioner at home is on right now, and I think it's louder sitting here at my desk than the Planar is when I'm lying in my berth on the boat.

I just wanted to clarify that when I was speaking of exhaust noise as a factor (for me), I was referring to the noise outside the boat. Everyone is different, but I can easily imagine myself in an utterly quiet, still anchorage as the sun comes up.... and then being reluctant to be the one to break that moment by firing up a heater with a "jet engine" type exhaust (so instead shivering).

That obviously does not apply to everyone, but I don't know the OP, so just mentioning it as something that may or may not be a factor depending on personal preference. The Wallas exhaust is quite a bit quieter, so that tips the scales in its favor for me.
 
I just wanted to clarify that when I was speaking of exhaust noise as a factor (for me), I was referring to the noise outside the boat.

Ahhh, thanks for explaining.

On mine, I can't really hear the exhaust. I probably run it more on the hard, in the winter when I'm down there working on the boat, than in any anchorage. I have to hold my hand above the exhaust to be able to tell whether or not it's working. This may be a by-product of my long-ish exhaust pipe. Or maybe it's because I don't have a hose on the combustion air intake, so there's no restriction there.

But, yeah, I wouldn't want to be that guy in the anchorage!
 
We installed a small Wallas in our (small) Rosborough last year and were totally comfortable doing the AICW down from Norfolk this past January/February (long story). The admiral thinks it was our best boat project to date based on the plentiful supply of warm (and dry!!) heat they produce.

We draw our fuel from a 2-1/2 gallon "day tank" which usually lasts us 2-3 cold (30's-40's) nights. We found the Wallas lived up to it's quiet reputation-- inside the boat we only hear a soft tick of the fuel pump. Outside the boat you only hear the air escaping from the exhaust pipe, much quieter than an auto exhaust.

A couple of thoughts based on our installation:
1) Choose your heater size wisely based on your boat and temperature range of expected usage. Our Wallas has (only) a 3:1 heat output range and also must also always be "on". Some fellow Rosborough owners with similar heaters have complained about getting too much heat at times.
2) We expanded that 3:1 heat output ratio by adding a diverter valve on the heater air input duct so we can adjust the mix of fresh and recirculated air. On cool but not cold nights, we can "force" our heater to heat 100% fresh cooler incoming air which can reduce the output temperature. On very cold nights, we can recirculate 50% of the pre-warmed cabin air if needed. The diverters were not Wallas brand but were easily adaptable.

3) Running ducts on our small boat was a challenge in a few places and we fabricated a few fiberglass ducts (using some plastic film coated foam male molds) that allowed us to maintain a constant cross section area duct while squeezing around and behind some obstacles. We glassed over 3+ of the 4 sides of a duct, leaving a narrow opening, gouged out the foam mold then glassed over the remaining 4th side. The result was similar to the hard plastic ducts you see roaming around under the dashboards in some autos and the interior finish of the ducts was very smooth and slick.

4) We also used a diverter valve on one of the two heater outputs to allow us to divert air to either our V-berth or to the helm station while the other output was dedicated to our dinette.
 
I have had Webasto, Espar, and Chinese brand X recently, Chinese being the best value. Downside is the Chinese installation and operations manuals are worthless. Upside is that it has more features, including a remote that allows my wife to turn on the heat while in bed. Plus, it indirectly supports China's rational policies on firearms and population. Or is talking about China only allowed here for anti China statements??

The Chinese heaters don't mention the length of ductwork runs. Others do in the fine print. It is very important for proper operation. All makers sell exhaust and hot air ducting in little expensive lengths. Check out switching to large foam pipe insulation for long runs of hot air through unconditioned space. Look at using 3/4" copper pipe for exhaust. Even though not cheap, it is cheaper, more efficient, and easier to wrap with fiberglass tape for insulation than is the corrugated stainless exhaust pipe. Copper also allows for a DiY fabrication of an effective exhaust muffler. It is possible for not just quieter but for so silent that others in quiet anchorages do not notice the heater is running.
 
Thanks very much for the replies.

Living in Sydney where our daytime winter temp is about 18-20 degrees(65-68 Fahrenheit) with nighttime temps not usually falling below 8-10 degrees(47-50 Fahrenheit) we don't need the heat capacity that some of you do living in those cold northern winters.

Probably by now some of you are thinking-what a whimp, call that winter!

Some of the brands mentioned I am familiar with, so I will look them up.

As an aside, regarding the comments made regarding Chinese brands all I will say is that we here in Australia have been on the receiving end of some pretty outrageous bully boy tactics from China regarding our trade,all this for our government speaking up about the need to investigate the origin of the Covid 19 virus.This has caused real hardship for some of our industries.

Anyway enough of my rant.
 
"I have a Dickinson stove, which I wouldn't recommend to most people, as it is pretty old-school."

Old school it may be , but with a gravity tank and an H smoke head it is one of the few heaters that can be turned on in Oct and off in May with no maint, or electrical requirements.

Sadly they are only about 20,000 BTU so are restricted to boats with smaller heating needs. Same as about 4 plug in 120v heaters.
 
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I went to the unusual route. Having a 54’ steel boat, requires lot of heating in the winter. I did not want to listen to a roaring heater/pump, so I picked the old school. The goal was to heat the salon and below deck, where the main and guest cabins are located. I wanted a silent system. I wanted a furnace, which needs no electricity. So, I bought a large Refleks heater.
It is a gravity feed diesel, uses very little oil. It can run 24/7, as long the feed tank has diesel in it. My feed tank is 6g and it can feed the furnace for 3-4 days none stop. It also has a cook top plate.
I chose the version with a heating coil inside. This coil is connected to hoses, going out and back in. The circulation of the heated water is managed by 2 solar water circ. pump, which is totally quiet and uses very little power. The hoses travel down to the ER, where they connect to 3 iron radiators (they make them pretty now). A large radiator heats the main, and two others heat the guest cabin and the shower. There are shutoff valves at each leg for maintenance.
The furnace heats up very fast. The radiators follow slower. If I let it run continuously, it keeps the boat nice and dry and comfortable. I do not like to sleep in warm room, so I run the pumps at low rpm. They are totally silent.
The system is very low maintenance and designed for long boats in Europe and northern fishing boats.
The furnace is available from one vendor in the US, to my knowledge. Since I wanted a particular model, with coil and cooktop, I bought it from a German reseller. These furnaces made in Denmark. Shipping is not cheap, but I paid close to $2800 for the large model, including shipping. So, it was not bad.
The radiators are slim design, white color, and quite simple to plumb. The hoses are regular heating hoses for marine use.
At the local shop, where all the mentioned furnaces are sold, I was quoted $7-8000 for a system. As of now, this setup cost me around $4-5000, and it is custom made for my needs. This includes all the valves, expansion tank, thermostat control, gauge, furnace, pumps, hoses, fittings.

IMG_0203.jpgIMG_0907.jpg
 
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My Webasto fan died and it was cheaper to replace it with a Chinese knockoff that performed just as well as the Webasto.
 
To size a diesel heater there are about 137,381 Btu in a gallon .

Figure a drip pot burner is 75% efficient a gallon an hour should give near 100,000 BTU per hour.

In our 90/90MS a Dickinson with a 7 turn coil required 2 GPD during most NYC winters, 20-25 at night , just above 32F days.

With our personal coldest -14F it required 4 GPD, to keep the interior T shirt friendly.
 
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