Eberspacher and fuel tank

[Clyde_Wanderer]

Fitting the eber to my boat, but not sure about fuel levels.
The heater unit is situated about the same level as the bottom of my main fuel tank and the top of the tank is aprox 280mm above the fuel inlet point of heater.
Is this arrangement ok?
Should I tap into the bottom of tank, or use a stand pipe from top of tank?
The manual does not cover his event.
Good advice is as always, appreciated.
C_W

 

[fireball]

I'd come out of the top of your fuel tank, the pump will draw the fuel through and you won't have any problems with
1) having to drain the tank to put the outlet in to start with
2) have you managed to seal the outlet 100% .....

Our Eber is probably in line with the top of the tank, but the fuel pipe does run down quite low before coming up to the heater. The pump is within 1' of the fuel tank.

 

[Heckler]

www.espar.com will give you the manual, it is very specific about fuel pipe fitting, all in there, the techie that taught me said that always best practice to fit a stand pipe in the fuel tank. once the pump has sucked its first bit of fuel it shouldnt drain back if all the joints are tight. rule of thumb also is short suck, soless than a metre on the suction side, be careful with the fuel pipe here, only use eber stuff with a small bore, lots on ebay is fuel leak off pipe which is a bit big, gives the small capacity pump too much work to do if it is a bit marginal. the outlet, push, side of the pump is ok to pump quite a few metres.
stu

 

[Clyde_Wanderer]

[ QUOTE ]
www.espar.com will give you the manual, it is very specific about fuel pipe fitting, all in there, the techie that taught me said that always best practice to fit a stand pipe in the fuel tank. once the pump has sucked its first bit of fuel it shouldnt drain back if all the joints are tight. rule of thumb also is short suck, soless than a metre on the suction side, be careful with the fuel pipe here, only use eber stuff with a small bore, lots on ebay is fuel leak off pipe which is a bit big, gives the small capacity pump too much work to do if it is a bit marginal. the outlet, push, side of the pump is ok to pump quite a few metres.
stu

[/ QUOTE ]

Thanks Stu, What I was worried about is, if the level of a full tank is 250mm above the bottom (mounting surface) of the heater, could the fuel siphon through the pump to fhe heater causing it to recieve excess fuel during running.
I understand the way you are adising routing the pipe.
2mm bore stand pipe fitted in top of tank, but then I would have to run the 2mm bore supply to pump pipe from the stand pipe at tank top down aprox 600mm to pump, which has to be fitted about 200mm below heater, then 1.5mm bore pipe from pump up to heater.
Do you reckon this would be ok?
None of the manuals describe a situation where fuel tank is above level of heater unit.
Thanks, C_W

 

[Clyde_Wanderer]

[ QUOTE ]
I'd come out of the top of your fuel tank, the pump will draw the fuel through and you won't have any problems with
1) having to drain the tank to put the outlet in to start with
2) have you managed to seal the outlet 100% .....









Our Eber is probably in line with the top of the tank, but the fuel pipe does run down quite low before coming up to the heater. The pump is within 1' of the fuel tank.

[/ QUOTE ]


Thanks Fb, I dont quite understand,"have you managed to seal the outlet 100%".
Cheers, C_W

 

[Heckler]

HMMM, I see what you are saying, dont know is the answer. However the diagram on page 10 of the D2 manual is pretty specific with the heater above the pump. The tick tick pump has valves in it but they are only to shuttle the fuel one way and wont stop siphoning, and the eber itself doesnt have anything in it to stop siphoning. It is quite a crude device really, there are just internal drillings to the combustion chamber and it is the control of the pump tick that governs fuel flow. if it did do siphoning it could concieveably flood the pump when it is turned off.
My druthers would be to mount it higher.
Stu

 

[fireball]

[ QUOTE ]
"have you managed to seal the outlet 100%".

[/ QUOTE ]
If you drill a hole in the bottom of the tank to feed the Eber, then you have to ensure that the fitting is 100% sealed so you have no fuel leak from the tank where you have drilled ... if you put the hole in the top of the tank then you don't generally have fuel at that level, so if there is a small weap then it is not so critical, although you'd probably want to fix it - it won't stop you sailing.

 

[Kylora]

C_W

I don't have any experience of heaters, but I would think that if you have a small bore pipe, full of fuel, which terminates in a space open to the atmosphere ( the combustion chamber ) at a level lower than the fuel level then it will syphon.

This would happen irrespective of whether the fuel came off the bottom of the tank or through a dip tube.

Maybe the pump is designed to positively shut off the flow when not activated - I don't know.

You might need to fit a solenoid valve which is only driven open when the heater is firing.

The easiest solution might be to find a different position for the heater so that it is above the fuel level, or fit another small fuel tank below the level of the heater.

Ash

 

[cliff]

[ QUOTE ]
What I was worried about is, if the level of a full tank is 250mm above the bottom (mounting surface) of the heater, could the fuel siphon through the pump to fhe heater causing it to recieve excess fuel during running.

[/ QUOTE ]
My setup has the tank above the heater - I have no problem with siphoning.

Tick-Tick is fed from the main fuel feed line with the take off just upstream of the primary filter. No standpipe. I did fit an inline filter just upstream of the tick-tick.

Fuel lines to the tick-tick are 8mm from tank then 6mm from the takeoff point to the inline filter and 6 mm from the inline filter to the tick-tick (then 1.5mm (eber supplied) from the tick-tick to the heater.)

I have not had any problems with this setup and it saved the hassle of fitting a standpipe.
---------------------

Artificial Intelligence is no match for Natural Stupidity

 

[Nauti Fox]

I used a separate tank on mine as the fuel line would have been a long run (eber fitted midships). The tank cost me about £60.00 and has a capacity of approx 45 litres.

 

[steve28]

the fuel pumps dont allow anything to pass unless they are operating so syphoning isnt an issue

 

[earlybird]

I have an elderly Wallas heater, not quite the same I know, but it might be relevant. It pumps fuel from its own tank. The fitting instructions stress that it is essential that the fuel level in the tank remains below the heater level at all angles of heel. The reason is obviously that the pump valves would otherwise allow forward flow by gravity.

 

[Clyde_Wanderer]

Thanks everyone for your replies.
I am interested in your reply in particular Cliff and Steve28.
Firstly seen as Eber dont issue a specific warning (like Wellas do) against fitting the units below the head of fuel I would have come to the conclusion that the pump will not allow any fuel past under normal circumstances.
What you are saying about taking from your main fuel line is described in detail in the manual, also my fuel line runs forward to primary filter on a horizontal plane and about the same level as the heater, although, technically it could still siphon as it picks up from tank top and then drops down to an aprox level of 450-500mm below tank top.
But as Steve says the pump wont allow any siphoning.
Cliff, what size of in line filter have you fitted in the 6mm pipe? as it would be nesseccary to fit one in that set up.
Is the 6mm pipe rubber?
At the worst scenario,I could fit a small 10-15 ltr tank under the sb quarter berth, but it would mean fitting another deck filler, or having to take it out to fill, although 15 ltr would probably last me the whole season.
I will need to sit down and weigh up the pros and cons before deciding on the final arangement.
Thanks again everyone for your advice.
C_W

 

[cliff]

I picked up the inline filter from an HGV spares depot. the filter is about 2" dia and about 3½" long. The piping is diesel return tubing - "rubber" but "diesel proof"
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Artificial Intelligence is no match for Natural Stupidity

 

[whipper_snapper]

What about taking it off from the spare outlet that you probably have on your primary fuel filter ?

(As others say, I would have no worries about siting the pump/heater below the fuel tank)

 

[earlybird]

[quote)

(As others say, I would have no worries about siting the pump/heater below the fuel tank)

[/ QUOTE ]

I think that I would. At least, I'd want to know the detail of whatever it is that stops gravity flow of the fuel. It seems to be all that stands in the way of the entire fuel tank contents being dumped in the bilge. If it's just, say, a spring loaded valve or a float valve, I wouldn't see it as being entirely reliable. Maybe it's more positive than that, I don't know!