I plan on adding a Webasto hydronic heater and the instructions from Sure Marine are pretty clear about limiting the length of the exhaust hose. It only uses a 22 mm exhaust hose. I plan to mount the heater in the lazaretto with a about a 3 foot run to the transom.
Fuel pickup location for a Diesel heater
- Thread starter mermike
- Start date
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,298
The run on my heater a Wallas 40DT is about 6 ft. It was recommended to exit the side stern quarter about 2 plus feet from the transom. Rationale, that the exhaust did not get blown back, roiled over the transom into the cockpit. Exhaust swept beyond the stern backwash.
Caution was advised to give the tube a foot or more loop to assure water does not siphon back up the hose.
Caution was advised to give the tube a foot or more loop to assure water does not siphon back up the hose.
I ran it on the bench and took some photos with the Flir, will upload one tomorrow. I had some unexpected work show up at the shop so I won't get back to the boat and start the install until the 20th or so. Nothing like waiting for the last minute. Brrr.
Dang, don't you hate it when work gets in the way of sailing.
Like most DIY projects, I checked with some of my cruising friends and found a heater offered by Amazon. The prices are under $200. for what seems to be comparable to the $2500. models at marine supply dealers. My friends have used these knock-offs for three winters and have been impressed with their reliability and functionality. As they both stated “if it breaks, I can afford a few more to replace it. Anyone else using a “not-so-elite“ model?
Self installed our Wallas 40D diesel heater several years ago and wrote an article about it here. Hunter 42 Owner Modifications and Upgrades No inspection port on our tank and no worries about a few small metal bits in the tank, which would get collected in the filters. The pickup tube is shorter than the engine tubes so as to avoid starving the engine of fuel.
I briefly considered using a knock-off and opted against it for a two main reasons, installation support and reliability. Sure Marine offers good support and installation instructions and a reliable product. Yes, it will cost more and I could buy several of the knockoffs for the same money, but the knockoffs will never fail when it is convenient and I don't want to deal with being cold in some relatively isolated place and dealing with repairing or replacing it.
I think that the risk of failure for a diesel heater installed under my bunk is not that it stops working on a cold night. I think that either starting a fire on-board or killing me quietly with CO poisoning would be the failure modes I would be concerned with. A CO detector only gives you a few minutes to wake and run. I know a couple folks who survived CO on their boats, and they say it is like gently falling asleep - you do not panic, just keep getting deeper.
That's problematic on a diesel. Foremost is the risk of introducing air in the fuel line. Second is reducing fuel pressure underway. Tapping the return line means that it would only work when the engine is running. A separate tank or fuel pickup is a necessity.
I'm starting to lean towards a separate tank. I had a half pint of diesel handy and used that to run it on the bench. Went through it pretty fast. Granted, the shop was cold and I wanted to see what full output was iike (very satisfying). But I only have 17 gal of fuel storage to begin with. I don't motor that much but a separate tank would act as extra fuel storage and allow the occasional fill up with kerosene. It would also keep the fuel pump in the lazarette.
Something like this container, well-secured. Make it removable so I'm not sticking the fuel hose down in the lazarette to refill it.
I'd install the fuel tank tap in place of the pour spout.
Something like this container, well-secured. Make it removable so I'm not sticking the fuel hose down in the lazarette to refill it.
I'd install the fuel tank tap in place of the pour spout.
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 22,298
Fuel management is a rational concern.
The Wabasto EVO 40 says their heater consumes 0.18-0.43 liters/ hour.
Your 17gal tank holds 64.4 liters fuel
A 5 gal jug holds 18.9 liters of fuel
When the temps drop to Zero Celsius your going to be running to a fire on the shore or cranking on the heater.
You can run the heater for roughly
It all boils down to how you want to enjoy and sail your boat.
The Wabasto EVO 40 says their heater consumes 0.18-0.43 liters/ hour.
Your 17gal tank holds 64.4 liters fuel
A 5 gal jug holds 18.9 liters of fuel
When the temps drop to Zero Celsius your going to be running to a fire on the shore or cranking on the heater.
You can run the heater for roughly
- 148 hours flat out from the fuel tank
- or 41 hours on the fuel jug before you need to refill.
It all boils down to how you want to enjoy and sail your boat.
Thanks for the maths! I think the numbers support a separate 5 gal fuel jug. I could see drawing the main tank down very easily. We do like to sail in the winter occasionally. The weather is mild compared to Idaho and it's uncrowded and peaceful in most anchorages. And there's wind. Sometimes too much!
You are over thinking this. Why not go with your original plan? Your Plan “B” seems like a lot of unnecessary extra work and potential trouble. Not only will the container have to be well secured, which in itself is not trivial, it will need a venting system preferably to the outside so air replaces the diesel as it is used. Install the pickup tube in the inspection hole, buy the spare container, fill it with diesel, store it wherever (anchor locker, lazarette, lashed down on your life lines, etc), and when you get low in your main tank, whether it is due to engine use or heater use, top it with the spare container.
Bad idea. Risk restricting fuel flow to the engine, which is used for both combustion as well as injector/rack cooling.