Gas or diesel heating?

[Adrian]

I am looking to buy a heater but am not sure whether to buy a gas fired(Propex) or diesel (Mikuni, Eberspacher). I can get hold of a cheap (Friend in the Business) diesel but I have no diesel on board and no inboard engine , I’ve heard that starting the diesel type can be a problem if your batteries are not at full charge or your engine is not running, anybody got any experience of this? Does the Propex have the same problem?
Any info on either type used on a small boat 24’ Jeanneau with out an inboard would be appreciated.


Adrian
<A target="_blank" HREF=http://www.kydproducts.co.uk>http://www.kydproducts.co.uk</A>

 

[tony_brighton]

Diesel Heaters (Eberspacher for example) draw a lot of curremt whilst starting up because of the glow plug and fuel pump. Some people have experienced problems starting with low battery charge but cant say I've noticed yet. The solution has been to start the engine when firing up the heater but then it runs fine and the engine can go off.

 

[bedouin]

I'm just considering the same issue - but from the situation of having both Gas and Diesel installed (toss up between the Eberspacher D2 and the Propex).

Most of the plusses are for the Propex:

It is cheaper to install, does not need regular (expensive servicing), is probably more reliable, does not require the heavy start up current, takes less electric power than the diesel when running and burns more cleanly than diesel - so no sooty exhaust.

The main advantage with the Eberspacher is running cost. The propex burns about 110g of Gas an hour - in other words each cylinder on my boat (camping gaz) can run the heater for approximately 24 hours. That is probably fine for getting the odd hour of heat in Spring or Autumn, but if you were running it for hours every evening in winter it would get expensive, and be inconvenient in having to replace the gas cylinder every few days.

The other advantage of the Eber is that it appears to be better suited for installation in the marine environment - the lagged exhaust and single hole looks better than the propex twin hole fitting.

I am undecided - but I think in the end it comes down to the expected usage. For light usage the Propex looks good, but if you anticipate heavy regular usage then the balance shifts towards the Eberspacher.

 

[pvb]

Diesel heaters draw a big current on start-up, because they have a glow plug which heats the diesel sufficiently to allow it to be spark-ignited. Typically, an Eberspacher will draw 20amps for a minute or so (at 12volts). If battery voltage is a bit low, the unit will shut down rather than ignite. Running the engine during the starting process normally cures the problem. Gas heaters don't have the same problem, as they're ignited by a simple electrical spark.

I reckon diesel heaters are inherently a bit safer than gas heaters. However, if you don't have an inboard, and don't have diesel, it would probably make sense to get a gas heater. The Propex you mentioned is well regarded, and fitted in loads of VW camper vans.

Gas consumption is fairly high - about 1kg every 6 hours - so you'll probably need to install an extra gas bottle. If you don't already have one, it might be worth fitting a gas alarm too.

The Propex draws about 1.5amps when it's running, which is similar to the average draw of a smallish diesel heater. I'm not sure, but I imagine the Propex is basically either on or off, whereas the diesel heaters usually have several levels of heating, associated with slower (and quieter) fan speeds.

 

[jimi]

Personally I think gas heaters have no place on a boat! Campers and caravans are OK with gas as gas drainage points are fitted. In a boat you can't. I lnow most of us have gas cookers but I certainly am very concientious about shutting at the bottle when not in use.

 

[pvb]

Gas cookers and heaters...

Yes, I'd basically agree with you. However, gas heaters are arguably equipped with more safeguards than gas cookers, so if you've already got gas on board there might not be a significantly increased risk (assuming good installation). Best safety investment might be a gas alarm linked to a shut-off solenoid at the bottle.

 

[petery]

I fired my Eberspacher up today for the first time after fitting it. It certainly draws 20 amps when it starts but it also draws 20 amps when it re-starts after getting to the set temperature when the cabin cools off.

Should this happen - I was going to call Eberspacher tomorrow - but I saw this thread.

 

[bedouin]

Where do you get that gas consumption figure? It is significantly higher than the figures I've seen in the literature and STs review a few months back.

If your figures are correct that tends to push the balance further in favour of the diesel

 

[pvb]

Back of a fag packet calculation...

Think the cold weather's affected my mental arithmetic! Propex quote about 120grams/hr - so maybe it should be nearer 8 hours per kg of gas. But for some reason their consumption rating for Camping Gaz is much higher. Why would that be? Is calorific value different??

 

[lauradee]

yes to calorific value

yes
have got figures in office will post tomorrow
stu

 

[lauradee]

more safe guards

we quite happily get our matches out and fire up the gas stove yet worry about a more regulated safety device fitted piece of gas machinery ?
i dont think southampton calor centre (and by association calor gas) would be selling them if there was any doubt about their safety.
but there again the old "urban boating myths" stop us from doing things which are safe and logical.
you can just see them now in the corner of the bar, lots of tooth sucking, gas on boats, suck, suck, dangerous, blow up, wouldnt have it on mine.
no more dangerous than gasoline or diesel for that matter if the rules are followed
stu

 

[jimi]

Re: more safe guards

No doubt about their safety per se, but the more gas lines installed the more chances of a leak .. not suggesting legislation, just personal preference!

 

[Avocet]

Re: more safe guards

I've had a small Propex for about 4 years now. It was easy to fit and uses very little electrical current (as has already been said) but I think its a tiny bit noisier in operation that my friend's Eberspacher.

For me, however, the main disadvantage is that if the Propex is running on Butane, it doesn't work when the weather is really cold because the butane freezes! By "really cold" I mean cold enough for a frost. I'm told the solution is to convert it to run on Propane (the darker bottles) which is more volatile so it works at lower temperatures. The conversion is very simple (just a different regulator I think) but the Propane bottles won't fit in my gas locker.

Other than that, it's been perfectly reliable. The only problem I ever had was after a knock-down and that was just because water had flooded the combustion air inlet pipe. As soon as it was emptied, the unit worked fine.

 

[stubate]

04:24

04:24 is that A.M?
good god man what are we doing at that time?
s

 

[jimi]

Re: 04:24

Sorting a sodding database ...

 

[Adrian]

Thank you all for your posts, i think it will be the Propex, ill let you know how i get on!!



Adrian
<A target="_blank" HREF=http://www.kydproducts.co.uk>http://www.kydproducts.co.uk</A>

 

[pvb]

Make sure you get the latest one...

Propex now sell the Heatsource 1600, which is smaller and (allegedly) more efficient than the previous Compact 1600 model. There are quite a few Compacts lying around on suppliers' shelves, so be careful you get the new model.

 

[lauradee]

thanks for info about gas

used to have the same prob with my land based caravan but as you say as soon as i changed to propane (red cyl, different reg, very cheap to change, no prob) no probs, am now contemplating fitting the propex propane to my sea based caravan, bene 351,
the bottle should fit
stu

 

[Alexis]

Have you ever thought of a simpler system such as a fuel stove? (Refleks)
No sensitive electronics, no noise, no high precision injectors, no electricity.

Mine has a serpentine that enables me to heat 3 small radiators and 20 litres of hot water,and has also the added benefit of a cooking plate on top.

Why not KISS ? (Keep It Simple and Stupid)

If you're interested, check out this site:http://www.refleks-olieovne.dk/

 

[Adrian]

i did look at a stove but was worrid about my two young kids touching it, i can site the propex in a cokpit locker out of the way.

Adrian

Adrian
<A target="_blank" HREF=http://www.kydproducts.co.uk>http://www.kydproducts.co.uk</A>