Heaters. Propane? Diesel?

[mitiempo]

Originally Posted by CarinaPDX

The problem arises when the fuel line at the tee has a vacuum when the engine is running. Buy a Walbro boost pump and install it in the heater fuel line just after the tee. Or use a day tank which gravity feeds the engine and heater.

Greg

Wallas heaters have their own fuel pump - they do not need a Walbro pump. Do not pull fuel from the engine fuel line - install the supplied dip into the tank - a simple job.

[Jim Cate]

Originally Posted by mitiempo

Wallas heaters have their own fuel pump - they do not need a Walbro pump. Do not pull fuel from the engine fuel line - install the supplied dip into the tank - a simple job.

Not so simple if your boat has multiple fuel tanks, as many cruising boats do. And access to the top of the fuel tank(s) is not always readily available... remember, there are no ten minute jobs on a boat, or usually, ten hour!

Jim

[Captjohn1974]

Have you considered using your engine coolant to supply a heater? Cheap and trouble free. Just throwing that out there.

Only thing is it only works when your engine is running.

[mitiempo]

Originally Posted by Jim Cate

Not so simple if your boat has multiple fuel tanks, as many cruising boats do. And access to the top of the fuel tank(s) is not always readily available... remember, there are no ten minute jobs on a boat, or usually, ten hour!

Jim

As long as there is access to the tank top it is easy. I have installed several without issue, in both plastic and aluminum tanks.

[mitiempo]

Originally Posted by Captjohn1974

Have you considered using your engine coolant to supply a heater? Cheap and trouble free. Just throwing that out there.

Only thing is it only works when your engine is running.

On a 52' boat that would be ineffective. A single bus heater works but you need more than that to heat a boat this large. And yes the engine would need to be running - pretty inefficient just for heat.

On a boat that large the better solution is a hydronic system which is boiler fed - Hurricane, Kubola, or similar. Or a large Espar. Wallas does not make a forced air heater for a boat much over 42' to 45' depending on volume.

[leftbrainstuff]

Originally Posted by basssears

Thanks RamblinRod, previous system was a Wallas that's why I'm leaning that direction for replacement... even has a Wallas controller (unknown if working or not) installed already. So I should be good on ducting, although I have to investigate further... as others have pointed out the ducting might not have been done right, could even be the reason there's no heater in there anymore (bad ducting setup causes premature failure and you remove the heater).

Interestingly the Wallas installation manual states:
"If the device uses the main tank of the boat, note that the device cannot take the fuel from the same fuel output line as the engine of the boat."
... so looks like I have to put another hole in my tank. I plan on putting in a bus heater too so doubt I would use this much while underway under power, but I have also heard stories of diesel heaters that won't run well when the engine's running when you share a fuel supply (I think the engine takes all the fuel it wants leaving not enough for the heater).

We pull diesel for the heater from our day tank for our espar.

One button operation.

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[Onemoreproject]

I installed a Wallas 30dt diesel heater this winter. It heats my 36' boat on the lowest setting when night time temps were in the low 30s. We havent had any condensation in the boat this winter because the heat is dry and circulates to the outside. We run the heater about 14 hours a day and it consumes about half a gallon of diesel per day and 1.2 amps of power per hour. Install was easy and we didnt bother with the heat ducts. If temps were lower we would run one vent down to the floor in the main salon.

[psneeld]

I have a Wallas 40DT and the easiest solution for me when I got rid of my large bottom feed steel tanks and went to poly tanks, was to get a discarded 2.5 gallon outboard oil jug, and drill a tiny hole in the top...and one for the fuel line.


Always fresh fuel, easy to see how much left, and lasts 3-4 days of light use or about 2 days with the heater on high. I plumbed a small fill tube over to it from my fuel manifold and just pump it full as needed (the feed is after main fuel filters so it is very clean).


The 2.5 gallon jug looks identical to the Wallas 2.5 gallon poly tank, just doesn't have the fancy fitting on top but can be bought separately.


The easiest way to plumb a top fed tank with no extra feeds is through the vent line and Wallas has "how to" on their website I believe.

[basssears]

Great info here, thanks for everyone's input... going to quote a few different posts here in one (I think )

Originally Posted by DeborahLee

I installed a Red Dot heater used in school buses $110 connected to the hot water lines off engine.

This is definitely on the list as well... the more heat the happier the admiral. In fact, end goal is probably three sources of heat... Wallas diesel forced air, Red Dot for when underway under power, and probably eventually a Dickinson solid fuel bulkhead heater for taking the chill off, ambiance and even more dryness.

Originally Posted by mitiempo

As long as there is access to the tank top it is easy. I have installed several without issue, in both plastic and aluminum tanks.

I do have an access hatch in the sole right above my plastic tank. Question is best way to make 1" hole in poly tank without getting a bunch of plastic shavings in the tank? I have heard some say hole saw until just before you break through then finish with a box cutter?

Should drain the tank first?

Originally Posted by Onemoreproject

I installed a Wallas 30dt diesel heater this winter. It heats my 36' boat on the lowest setting when night time temps were in the low 30s. ... Install was easy and we didnt bother with the heat ducts.

Awesome to hear first hand experience. If 30dt is good on your 36' might be a bit of overkill on my 32' pilothouse, but it's only a $300 difference between the 20dt and 30dt, I figure I might as well go with higher capacity just in case, as I will also want to keep air moving through the cabin even when it's cold and heater is running.

So did you just mount the heater itself with the two warm air ducts pointing out into the cabin?

-- Bass

[mitiempo]

Originally Posted by basssears

I do have an access hatch in the sole right above my plastic tank. Question is best way to make 1" hole in poly tank without getting a bunch of plastic shavings in the tank? I have heard some say hole saw until just before you break through then finish with a box cutter?

Should drain the tank first?



Awesome to hear first hand experience. If 30dt is good on your 36' might be a bit of overkill on my 32' pilothouse, but it's only a $300 difference between the 20dt and 30dt, I figure I might as well go with higher capacity just in case, as I will also want to keep air moving through the cabin even when it's cold and heater is running.

-- Bass

Don't bother draining the tank. A vacuum beside the bit while you drill helps, as does grease on the hole saw to catch the chips. Go slow, it's only plastic.

It is a 22dt, not a 20DT. For your boat I would install the 30DT, especially if you want to cruise all year.

[mitiempo]

Originally Posted by Onemoreproject

Install was easy and we didnt bother with the heat ducts. If temps were lower we would run one vent down to the floor in the main salon.

Pretty much defeats the purpose of heat throughout the boat. I would run 2 outlets, say one to galley and one to main salon. The cold air returns should be run as well.

[Sandero]

Originally Posted by jtsailjt

Isn't that what I wrote, and even explained HOW the diesel heater reduces (didn't say eliminates entirely) moisture in the air on your boat, by displacing some of that moisture filled air with outside, drier air, thus reducing (again, not necessarily entirely eliminating) condensation?

In my opinion, that's the primary advantage of a forced hot air system that draws the circulated air from outside the boat over other systems that just heat the air present inside the boat so don't contribute as much to a change in the air or, in the case of unvented propane heaters, even add to the amount of moisture present. However, any vented heater will tend to dry a boat out because the heated air will naturally rise and pass through the dorade vents or small openings around the companionway, etc., carrying moisture with it and causing outside, drier air to gradually be drawn into the boat to replace it. But a forced hot air furnace such as a Webasto or Espar heater does the drying out job much more quickly because it is actively importing cooler, drier air and pumping it into your boat at a much higher rate.

I don't have much to compare to. My installation recirculates air draw from the area below the bunk, behind the engine. It is not from a return grill from the cabin. So it's kinda outside air... probably mixed with cabin air... there is some passages for air to move between the inside and the outside. For example my aft lazarettes are not directly connected to inside spaces. I do have one removable hatch board which allows me access from inside the boat to the non interior enclosed "storage" spaces. mechanical spaces... such as the rudder post area.

It's not as if the heater has a grille literally interfacing with the outside air... like a thru hull.

When the boat is closed up you don't face dying from oxygen starvation because of partial gas pressures and so it is with the moisture in the cabin air.