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SiteSurfer

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Here's a thing, I have been trawling for a diesel heater for the boat and have come across several systems which allude to being for boats but are not specifically "marinised" if that's a word!

Thing is that they are a lot cheaper, is this simply the word boat adding many pounds or are there specific things which need to be added/changed?

I will fit it myself, would happily buy second hand and don't need a massive one as the boat is pretty small (29ft) so I'm really on the budget end of the market. Thing is the wife has opted for a heater over a fridge conversion - something to do with cold feet and not going sailing in an ice box...
 

David2452

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If you are looking at the ubiquitious AT2000ST (though I consider that too small even for a 29 footer if you want proper warmth and noisy to boot) the major difference are in the ECU which will tolerate lower voltage, it may interest you to know there are over 20 different ECUs listed for the same size of heater, the air blower which is designed to work better with longer duct as the vehicle ones are usually of very low duct length and the higher minimum cut out voltage is there to protect the usually single battery also used for starting. If installing a new one yourself then a vehicle unit will not carry a 36 month on board warranty, same goes for if not done exactly to instruction. The same goes for the larger air units, wet systems become a lot more complicated. Do not do an import from Turkey or you will get no warranty at all unless you pay carriage there and back and lose the heater whilst all that happens. I often find that people thinking they are getting a bargain buying vehicle heaters wind up paying more than a proper kit by the time all the required parts are added. If you wanted to go used (refurbished with warranty) I may be able to help.
 

NUTMEG

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No connection other then a very satisfied customer. I purchased a s/h 3500 from David 2452 last winter and followed his installation recommendations to the letter. The heater has been superb, the boat is used all year around now and I wouldn't be without the heater.

Good price and very helpful chap.
 

lpdsn

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I'm not sure I'd fit a new diesel heater these days. They're really a hangover from the days when diesel was cheap.

Beware too that they take a fair bit of current from the battery. Use decent cables to minimise the voltage drop, but you almost need shorepower to support the current drain anyway, so by that stage a cheap fan heater is an easier solution. You can pay for a good few KWh for the difference in price between a fan heater and a diesel heater.

Also make damn sure the type you choose will run on red diesel. Eberspaecher, for example, aren't designed for red diesel (read the manual if you don't believe me) and coke up as a consequence - I sorted mine out, for now, by feeding it paraffin for a bit, but to be honest I barely use it.
 

SiteSurfer

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Well I'm determined to remove gas from the system and I must admit to having had very good returns from diesel heaters on both buses and campervans, plus I really really would like to avoid mains power where possible - for no other reason than I have a peculiar feeling about 240V + water.. (not to say I dont have a hookup socket - but would prefer to not be reliant on Marinas).

I'll PM you if thats ok David. It sounds like you have a handle on the situation and understand where I am coming from.
 

pvb

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I'm not sure I'd fit a new diesel heater these days. They're really a hangover from the days when diesel was cheap.

Beware too that they take a fair bit of current from the battery. Use decent cables to minimise the voltage drop, but you almost need shorepower to support the current drain anyway, so by that stage a cheap fan heater is an easier solution. You can pay for a good few KWh for the difference in price between a fan heater and a diesel heater.

Also make damn sure the type you choose will run on red diesel. Eberspaecher, for example, aren't designed for red diesel (read the manual if you don't believe me) and coke up as a consequence - I sorted mine out, for now, by feeding it paraffin for a bit, but to be honest I barely use it.

High current? My Webasto Evo 3900 uses about 3A, about the same as a decent chartplotter. If you can't run a 3A load for a few hours without shorepower, you need to review your battery capacity.

Red diesel? I ran the Eberspacher on my last boat for 19 years on ordinary red diesel. No problems.
 

alexsailor

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I agree with @pvb
I have Webasto Air top 5000. Fan and diesel pump do not use more than 4A.... On a serious boat, you do not notice that.
 

David2452

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High current? My Webasto Evo 3900 uses about 3A, about the same as a decent chartplotter. If you can't run a 3A load for a few hours without shorepower, you need to review your battery capacity.

Red diesel? I ran the Eberspacher on my last boat for 19 years on ordinary red diesel. No problems.

I have to say I thought I had entered a time warp for a minute, all the points were valid, with the empohasis on were, things have moved on quite a bit in the last 10 years, and even then most of the issues were bad install and set up related.
 

SiteSurfer

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I run dual batteries and in all honesty, if it meant extending the season - I'd add another just for capacity. I have been looking at the air top's and they look like a neat unit. Luckily in my boat theres a cavernous space which is crying for a small heater unit to be hidden in which is no more than 500mm from where i want to put the vents. I assume they don't get 'that' hot during operation and could be located on a strut which was epoxied to the hull - then vented to the outside world.
 

pcatterall

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Here's a thing, I have been trawling for a diesel heater for the boat and have come across several systems which allude to being for boats but are not specifically "marinised" if that's a word!

Thing is that they are a lot cheaper, is this simply the word boat adding many pounds or are there specific things which need to be added/changed?

I will fit it myself, would happily buy second hand and don't need a massive one as the boat is pretty small (29ft) so I'm really on the budget end of the market. Thing is the wife has opted for a heater over a fridge conversion - something to do with cold feet and not going sailing in an ice box...

It would be perfectly possible to fit something like a used AT 2000 ST and It would certainly heat a saloon on a 28 footer in spring and Autumn. With ducting and closable valves you could direct this into your berth area but probably not heat both areas together.
The used market is a bit of a nightmare though and a decent used kit would set you back a fair bit. The kits from Turkey are good but the warranty would be difficult to use in practice.
Marine grade components are especially important ( in terms of safety) where the exhaust/silencers and through deck fittings are used.
 

salar

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I installed a Webasto Air Top 2000 last year. As I understand it, you pay a lot more for one with a marine warranty but the only difference between the units installed in a boat compared to a campervan is the exhaust skin fitting, a stainless mounting bracket and a fuel tank tube. I bought the camper van version plus the additional marine fittings on a return to base warranty for several hundred pounds less than the "marine" version. Once installed it fired up first time and has behaved perfectly ever since. I would strongly recommend it! If you are careful and follow the instructions it is an easy DIY job for anyone competent. The installation is covered in various posts on by re-fit blog http://harley25refit.blogspot.co.uk/2014/05/more-work-more-progress.html
 
I don't know if I was lucky, but I got an AT2000 from Turkey about 5 yrs ago, and it has been utterly reliable. I needed an exhaust fitting, a 1 m length of exhaust pipe, and a fuel tank dip tube in addition to the heater, and the total cost was around £750, just over half the retail price of a marine one. It is very effective at heating the saloon of our Sadler 29, but there is only one outlet, in the galley (therefore the ducting run is short) but the heads and forepeak don't get much warmth. It is quite noisy, but SWMBO doesn't mind that, provided she is warm. It makes a huge difference in the shoulder seasons to be able to sit in the saloon wearing normal clothes in the evening, rather than having to keep loads of layers on, or getting into a sleeping bag. It is also good for keeping the boat dry. Fitting was straightforward, but took a while, if you include the removal of the fuel tank to steam clean it to get rid of diesel bug, and upgrading the service batteries to a pair of 75 Ah ones.....
 

SiteSurfer

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The Prospect 900 is quite useful in that its just one big saloon, so a couple of vents placed strategically would actually heat the whole of the shebang. All points noted - I'l have a chat to David of this parish to see whats available "officially" before looking at the make and mend market.
 

dom

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That's how mine is fitted. Works a treat. I did add a stopcock to isolate the Webby fuel pump though.

Interesting, I'd have thought air locks would pose a problem following extended heater use after engine shut-off. Happy to be corrected though.
 

pcatterall

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The Prospect 900 is quite useful in that its just one big saloon, so a couple of vents placed strategically would actually heat the whole of the shebang. All points noted - I'l have a chat to David of this parish to see whats available "officially" before looking at the make and mend market.

If you feel that the 2kw heater may not have quite the output you need then I find that the larger heaters ( Eberspacher D4) are not so much more expensive (on the second hand market).
If you try a standard mains heater ( when you have shore power) on 2 kw ( high setting) you will get some idea of your needs. With a large cabin and in mid winter 2k may struggle.
 
I had imagined that one simply split the fuel outlet from the tank and boshed a T piece in? (Obviously after the primary filter).

As I had to take the stainless steel tank out to clean it anyway, it was a easy job to fit the dip pipe, which gives an independent feed to the heater. I also cut the dip pipe so it is a good 2" above the btm of the tank, so the heater can't drain the tank. I understood this is the recommended way, to avoid problems with fuel starvation to the heater when the engine is running.
 
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