Heat and hot water

WanderingStar · #1 (**permalink**) 03-10-2011

I use my boat year round, though I don't stay aboard in winter. I want some heat, and my wife wants hot water (fussy!). I've never used an engine heated sytem, but I don't run the engine much, and the raw water stays cold in cold weather. My plan is to install a hydronic furnace in the engine room to provide both needs. There's the rub: those things are crazy expensive. The boat is 39', it seems the recommended furnace kit is about three grand. That's before the hot water tank and plumbing, heat lines etc. That isn't going to happen. Looking online I see surplus military truck heaters and generator preheaters for under a thousand. I know and agree with the standard response: use marine grade. But the matter here is that I can't afford marine grade. I also know that the same companies make heaters for boats and trucks. Can something designed to mount under the fender of a truck really be so frail that it will die in my engine room? After all, my Perkins is a tractor diesel.
Inviting opinions based on experience.

peikenberry · #2 (**permalink**) 03-10-2011

Quote:

Can something designed to mount under the fender of a truck really be so frail that it will die in my engine room?

The issue isn't, will it die? The issue is will it kill you? The biggest concerns with heaters are safety. Will it set your boat afire? Will it emit carbon monoxide and kill you? Those are the questions you should be asking. Marine heaters are designed so that they won't set your boat afire or kill you with CO. If the heater you are looking at will meet those requirements then Why Not?

And marine diesels are basically truck diesels with a few mods such as cams and cooling.

deniseO30 · #3 (**permalink**) 03-10-2011

here ya go! right on Ebay and in CT Planar Air Heater Truck/RV/Boat cabin Webasto, Espar - eBay (item 200581829456 end time Mar-30-11 17:14:41 PDT)

Faster · #4 (**permalink**) 03-10-2011

This may be a smallish unit, not familiar with the brand but though it's not nearby it's a starting point perhaps:

Boat heater for sale

svHyLyte · #5 (**permalink**) 03-11-2011

If you have a hot water heater on your boat you already have the makings of an inexpensive Hydronic system. On our boat I have a Heater Craft cabin heater that is tapped into the fresh water side of the engine cooling system. It will work even if the engine isn't running due to the heating of the water in the Raritan hot water tank while we are dockside. While the engine is running the fresh water pump circulates the hot water through the system. With the engine off, a small inertial recirculating pump in the in-put line recirculates the hot water and the system works very well.

See Heater Craft Auxiliary Cabin Heater

WanderingStar · #6 (**permalink**) 03-11-2011

Thanks, I keep the boat on a mooring, no shore power. I'm looking for diesel fired experience.

hellosailor · #7 (**permalink**) 03-11-2011

WS, I'm told the Espar/Esbacher marine heaters were all spun off their diesel BUS heaters, so you're not far off the mark. I'd expect a marine model to have some different accomodations for venting, and perhaps to use some different materials. For instance, copper and aluminum are just fine for all sorts of hoe and auto use, but mix them with fluids and salt air...not so good in marine use.
When you say "furnace" I think hot air, like the bus heaters, but when you say "hydronic" that's what is (to me) usually called hot water baseboard heating, run out through metal pipes and fins. The latter might be an issue in marine use.
I will say that is there's an Espar (etc) hot air heater in your boat, it kinda spoils you. Nice and toasty DRY.

mitiempo · #8 (**permalink**) 03-11-2011

Espar does make hydronic heaters as well as the forced air models. A more involved installation though as you need 12 volts and a thermostat installed at each outlet. Each outlet is larger than the air outlets would be.

WanderingStar · #9 (**permalink**) 03-12-2011

Thanks. Thinking.

BELLATRIX1965 · #10 (**permalink**) 03-12-2011

No direct experience, but another thought - I'm in your situation (want hydronic, diesel-fired, no shore power) and am considering the Proheat X-45. This is a truck heater, but can be adapted for marine use. The trick is to properly pipe the exhaust, and to avoid a long exhaust run. If it can survive in a box under a school bus in Maine, it can certainly survive in my engine room!

Here's a "marine" (read expensive) cut sheet:

http://www.suremarine.com/manuals/as...on/proheat.pdf

I'm not willing to pay big bucks at this point either, but have seen some good deals for X-45s on eBay. . . .