Diesel Forced Air Heater Fuel Supply Issue

[Astral Blue]

I have a Planar 8DM Diesel forced air heater installed on my boat. I have used it for two years and am very happy with it. In my original installation, I have been using the 2 liter fuel tank that comes with it. This past weekend, I plumbed a tee into my main fuel supply (after the Racor fuel/water separator). The line running between the fuel tank and the heater's pump is about 12 feet. It is on a slight incline, so there is no gravity helping the flow of fuel.

The plumbing part went well...until I turned the heater on. I discovered the piston pump that comes with the unit is not capable of priming the system. I want to give the pump a little help, so I purchased an second pump pump and am planning on installing it at the point I have teed into the fuel line. Here is the pump I purchased:

12V Universal Car Boat Fuel Pump Metal Solid Electric Diesel Petrol Hep 02A Set | eBay

I plan to have a separate switch where I turn it on with the heater. It's not the ideal configuration, but I want to give it a try.

If this does not work or the advice I'm given here shows my plan to be non-viable, I'm planning on reinstalling the tank that came with the unit and going back to my old configuration. I will use the pump to fill my heater's fuel tank as needed.

So, the 68 million dollar question is whether anyobdy has attempted this before. Your thoughts?

Thanks in advance!

 

[windmist]

It could be that you just need to disconnect the fuel line from the heater and let the pump prime the line. I put the fuel line in a clear glass jar and run the pump until there are no air bubbles.

 

[Astral Blue]

It could be that you just need to disconnect the fuel line from the heater and let the pump prime the line. I put the fuel line in a clear glass jar and run the pump until there are no air bubbles.

I tried it to no avail. The pump was not able to pull fuel adequately.

 

[FF]

>I'm planning on reinstalling the tank that came with the unit and going back to my old configuration. I will use the pump to fill my heater's fuel tank as needed.<

Or perhaps a larger gravity tank?

An inline fuel pump may over power the existing pump.

The solution Espar used was a remote float bowl as on a motorcycle carb.

The new pump fills the float bowl, your existing pump sucks from the bowl. every body is happy , no overpressure .

Remote float bowls are common on racing bikes . look on line.

 

[Larry M]

We had an Espar Furnace when we bought Hobo. The PO installed an auxiliary tank and pump. I believe the pump was a Walbro FDR-2. The system worked great.

Walbro FRD-2 Industrial Fuel Pump from Fuel-Pumps.net

 

[DavidM]

As you discovered the cheap Chinese fuel pumps have very little suction (lift) capability. The Walbro pump noted above has 48" (about 2 psi) of lift capability.

That is probably enough to deal with the static head and whatever pressure drop there is in the Racor filter. But it may not be enough to work when the propulsion engine is running, particularly at high fuel flows. Those flows will cause a further pressure drop in the Racor and might be more than 2 psi. If you have a vacuum gauge on the Racor, check its reading. Any more than about 1 psi and you will probably have a problem even with that Walbro pump.

David

 

[psneeld]

My Wallas heater required to suck fuel from a separate feed as engine suction would defeat the pump as does the restriction of other filters such as Racors.

The heater pump is good for 2 meters of head.

Also the fitting connecting the fuel line to the pump required numerous tightening attempts. Finally the tech adequately explained how to get it tight enough. There was no visible bubbles but it wouldn't pump.

 

[Retriever]

My Espar draws fuel from the same Racor as the generator.

There's a boost pump installed before the metering pump. When I'm back on the boat tonight I'll get the brand name (and model number if I can find it) off the boost pump.

I believe the system was supplied to Nordic Tug by Boat Electric and called the "Grand Mariner" system.

 

[C lectric]

i know this is not what was asked but if you have connected to the main engine fuel line then be carefull. Aside from the engine pump creating more suction than the heater pump can deal with you could have the engine pump pull air backwards and cause a main shutdown.

Yo may not see the problem at engine idle but more when the engine is working harder.

Be carefull.

 

[Astral Blue]

i know this is not what was asked but if you have connected to the main engine fuel line then be carefull. Aside from the engine pump creating more suction than the heater pump can deal with you could have the engine pump pull air backwards and cause a main shutdown.

Yo may not see the problem at engine idle but more when the engine is working harder.

Be carefull.

Thanks for bringing this to my attention. You have a good point. Just thinking through it...perhaps a check valve at the tee might prevent this from happening?

 

[Scary]

I think I would steeer away from the check valve

Thanks for bringing this to my attention. You have a good point. Just thinking through it...perhaps a check valve at the tee might prevent this from happening?

Just one more thing to fail. Do you have room for a a three gallon outboard fuel tank with a prime bulb. Perhaps though not elegant would give you the longer run time for your heater.

 

[CaptTom]

Thanks for bringing this to my attention. You have a good point. Just thinking through it...perhaps a check valve at the tee might prevent this from happening?

Sorry to dredge up an old thread, but it was either that or start a new one.

Did you ever get this working?

My Espar draws fuel from the same Racor as the generator.

There's a boost pump installed before the metering pump...

I was also hoping to be able to T off the generator fuel line, which has a dedicated pick-up in the tank. From there, it's a gentle down-hill run to where I hope to put my heater.

Any chance this would work without a boost pump?

Possible problems would be the heater fuel pump not being able to pull the fuel that far (20 to 25 feet), or the possibility that the generator lift pump would suck air through the heater fuel line.

Other suggestions? I can't reach the tops of my tanks to make another hole for a new pick-up. I don't want to have to pour fuel into the small tank that comes with the heater.

The other option I've toyed with is to fill the small heater tank via an electric fuel transfer pump, but then I'd need to keep an eye on the tank, which I'd prefer remain hidden. Plus it's another chore to maintain the fuel level. A float switch adds complexity, and the risk of a nasty overflow if it fails.

 

[ksanders]

You could try tee'ing off of the generator fuel line but I have hesitations that it'll work.

The reason is that when running the generator you'll be creating a vacume on the furnace fuel line.

I know it might be a pita, but I think in the end you'll get better results from a dedicated fuel source.

 

[Nomad Willy]

I have had a Wabasto for about 7years. Had some troubles many times starting up. My fuel was sourced from the engine fuel manifold and I had the troubles mentioned above. When I took my unit in to have it fixed (finally wouldn't run) they (Sure Marine) said it would last much much longer if I fed it kerosene. So I put a dedicated 2 gallon aluminum tank on the back of the cabin and replumed the system. It's only run so far on a four day cruise but it worked fine. The diesel fuel is just too dirty and my little "dossier pump" was unsuccessfuly competing w the engine system. I'm sure I'm "good to go" now.

 

[Astral Blue]

Sorry to dredge up an old thread, but it was either that or start a new one.

Did you ever get this working?

I ended up reinstalling the original fuel tank. I did purchase the fuel lift pump and am using it as a resupply pump for the heater's tank. I flip the switch on; and within 10 minutes, the tank is full. It's not the ideal solution, but works well.

 

[Jim Gandee]

Ed,

I'm late to the party here so FWIW my Webasto installation instructions clearly state the unit requires its own dedicated fuel feed. The manual further admonishes to never tee into a fuel line that will have a competitive fuel demand, i.e. Generator fuel line.

Glad you got your heater running!

Jim

 

[petdoc4u]

I just installed a Planar D8. Very pleased with it. We draw fuel from one of our diesel tanks, run is over 10' between tank and heater. When priming we disconnected the fuel line from the heater. We then cycled thru the start sequence several times until the fuel line was full and bubble free, then reconnected to the heater. The pump supplied with my heater has a built in check valve. I was advised against T-ing into the main or generator fuel lines by everyone I discussed this with. So far no issues with any aspect of the heater. We love it.

 

[Nomad Willy]

So are you "T-ing" in or not?
We did but had troubles for years.
Recently changed to dedicated tank and supply line.
And kerosene fuel.
Drawing off the engine's fuel manifold was a situation where the little "doser" heater pump had to compete w the engine fuel pump. The Racor filter and tank sump was also then part of the heater system. Was often hard to start. Part of the time I was drawing through a 2 micron filter core in the Racor. Heater was a small Wabasto. Works flawlessly now but little time on it.

Sounds like you've got the priming figured out. On the Wabasto control unit there is a "prime" button. Not sure what it does but it frequently helped w startup.

 

[grahamdouglass]

Dedicated tank

I have a plastic gas tank that I fill with kerosene. Kerosene burns very clean and I have never had a problem. The tank has a fuel level indicator and is in the engine room.

 

[petdoc4u]

On advice given by many, we did NOT T-in. We fabricated a "straw" which was installed thru an access port in one of our primary fuel tanks. We chose not to risk any problems with fuel delivery to our engine.

 

[FF]

If required to operate with a thermostat , not constant run, most of these units work far better with kerosene than diesel.

As real cold weather will be 3+ gallons per day a winter liveaboard should be figuring just where a 30+ gallon gravity can fit.

Sail boats can simply lay a bladder tank on deck for the winter or in the aft lazerette .

Sure its nice to use a huge fuel tank of diesel .all winter.

It might be the first time its emptied in years , and 5 gal jugs get heavy on a snow filled dock, but having it operate all winter trumps the hassle

 

[CaptTom]

I ended up using the small plastic "day tank" that came with the Planar. For testing, I filled it with kerosene. I'm working now on a fuel transfer system that will include the ability to draw and return from/to any of my four diesel tanks, with a 3-way valve that will also allow me to return to my heater day tank.

Still, I think I'll keep kerosene in the tank except when I'm using the system regularly, because I've heard so much about these units running cleaner that way, and replacement parts have to come from Russia.

 

[garrobito]

I just finished installing a planar diesel heater.. plug everything.. and nothing happened.. code 17, fuel pump faillure.. thinking replace for a similar fuel pump than Astral Blue.. very frustating after a couple days of work.. damm russian things!!

 

[Nomad Willy]

Garr,
Nice boat ya got there.
Not good at head seas?

I'm frustrated w my Wabasto also. Not the Wabasto's fault though. Put a fuel tank on the outside on the cabin and filled the tank on a rainy night w/o putting the filler cap back on. Water in the fuel system. After a lot of effort I got all the water out but I'm in "lockout" mode now re what the Wabasto tech says. Won't start. Took the whole thing out and will take it to Seattle Monday. It's super gouod when it works though. As I said it was my stupidity.
Good luck w yours.
By the way ... a Wabasto or other "dosing" pump may work on your unit. Something to consider if you get desperate.

 

[AKDoug]

Timely re-birth of a thread. I am installing a Webasto 4200 and my plan WAS to "T" into the fuel line for the engine after the primary filter. I knew the manufacturers called for a dedicated line but assumed that was so the heater couldn't draw down the fuel supply to the engine and run the tank dry. I do not have access to the top of my fuel tank to install a separate pickup tube (supplied with the heater) in the DIY kit.

My max fuel flow is under 1 gph, so I never considered that suction from the fuel pump could affect the heater fuel supply. I will now consider a separate fuel supply in a separate fuel tank, possibly in the stern.

Willy, I can't imagine your engine draws more fuel than mine does, so it was helpful to know you had this issue...

 

[Al]

My Wallas heater required to suck fuel from a separate feed as engine suction would defeat the pump as does the restriction of other filters such as Racors.


Strange, we have a Wallas D-30 and it is connected directly to the engine fuel feed line with a 'T' fitting.The run to the heater from the 'T' is about 8-10 feet horizontal. Pump is powerful enough apparently as there was and is no issues. Started on the first go after allowing pump to purge through the unit.

Al-Ketchikan

 

[rochepoint]

Garr,
Nice boat ya got there.
Not good at head seas?

I'm frustrated w my Wabasto also. Not the Wabasto's fault though. Put a fuel tank on the outside on the cabin and filled the tank on a rainy night w/o putting the filler cap back on. Water in the fuel system. After a lot of effort I got all the water out but I'm in "lockout" mode now re what the Wabasto tech says. Won't start. Took the whole thing out and will take it to Seattle Monday.

Don't know what model you have but maybe this will help.........

 

[Nomad Willy]

Doug, Al and Mike,
I ran mine for years T'd into the engine manifold. But now and then I'd have startup issues. And when I took it in for maint (showing 800hrs) and I couldn't get it to start nohow. They said it was badly crudded up and recomended I swich to kerosene. So I got a rather flat aluminum tank of 2.5 gallons and bolted it to the back of the cabin outside. Plumbed 1/2 copper pipe and 1/2 fuel hose. Worked perfect until I left the filler cap off on a rainy night.
Mike it's an "Airtop 2000". There's stripped slots on the power wires .. can't get the screws out. I'm gonna give SureMarine a shot at it.
Doug your engine is a little more fuel efficient so I'd guess they are about the same. I run at 6.15 knots.

 

[Al]

Eric, I failed to identify that I use #2 Diesel.

Al

 

[psneeld]

My Wallas heater required to suck fuel from a separate feed as engine suction would defeat the pump as does the restriction of other filters such as Racors.


Strange, we have a Wallas D-30 and it is connected directly to the engine fuel feed line with a 'T' fitting.The run to the heater from the 'T' is about 8-10 feet horizontal. Pump is powerful enough apparently as there was and is no issues. Started on the first go after allowing pump to purge through the unit.

Al-Ketchikan

Just passing on what both the manual and owners of the store said.

A lot of reading of installs and reviews...these tiny fuel pumps can be very finicky.

When my Wallas was having issues....the company replaced a pump under warranty even though it turned out not to be the problem.

That is how low their confidence in them is so I reigned my fuel supply and filters to spec just to be sure.