diesel heater, fuel lines

Hi
As mentioned there isn't a return. The wee pump only runs to the demand of the heater usually. Certainly on most anyway.
I'm not sure it would work from the fuel filter, especially if the engine is running. The flow would disturb the suction I'm sure. It's pretty sensitive. The wee pump even has to be set up at a certain angle.
As mentioned, you can take from the main fuel tank or do what I did (because I had a petrol boat)....just have a wee 12l outboard engine plastic tank, drill a small hole on outlet pipe and stick fuel hose into it. The wee fuel tank lasted a season easily and even had a wee gauge on it. You can of course fit your own remote gauge to it too.
 
On my boat, I have Dickinson Artic drip feed diesel heater (and very nice it is too). There is a little pump connected in the line which is connected directly to the main fuel tank. The pump is at the fuel tank end and a fair way away from the heater.

This is a 2psi "boost" pump from a performance car parts company. There is no return. There is an overflow which goes into a small plastic bottle in the locker next to the heater. But there has never ever been any overflow. The pump runs just occasionally.
 
I would not compromise the integrity of your engine fuel system by joining other services to it - receipe for disaster.
 
Heaters take a mere dribble compared to an engine. At all stages of an engine's fuel supply there is spare fuel, thats what all the returns are about. The lift pump can pump more than is required. So, there is spare fuel available.
But! If the engine pumps only operate while the engine is running, or are noisy then what ya gonna do for heat at night when the engine is stopped?

Best add another (or tee off) the tank outlet, a silent pump and another (spare) filter.
 
Ahh, just remembered the installation I worked on last year...
There were small (10 ~ 20L) tanks near each heater. These were filled by in-line fuel pumps from the main tank outlet manifold. so, main fuel storage was the big tank, but no need to run the noisy pump at night.
 
When looking into several of the options for our system last year I was lead to believe that the default set up was to have the pump drawing from a stand pipe in the fuel tank. I believe the pumps are best mounted near the tank, someone may know more about this than me but I was told the pumps can push the fuel further than they can pull it, so if your tank is aft and your heater is fwd then put the pump at the tank.
Teeing into a fuel pipe was a consideration but the general consensus said using the stand pipe arrangement was preferable.
Another easy alternative ,as the heaters draw so little fuel, is to mount a small slave tank , along with the pump, wherever you want that is relatively close to the heater.

I have to say the pump on our new Webasto is all but silent, much , much quieter than any I've known on earlier gen systems.
 
If you have big deep talks like Andy M you need to make sure the stack pipe reaches the bottom all but an inch or so otherwise you may loose your heating if by chance you run the tank low, on the other hand I've been to faults on heaters where the pipe is sat in the sludge at the bottom blocking it after a few hours running.
Don't T it into the engines feed as the supply may cause an air leak .
 
Dougal Tolan said:
Ahh, just remembered the installation I worked on last year...
There were small (10 ~ 20L) tanks near each heater. These were filled by in-line fuel pumps from the main tank outlet manifold. so, main fuel storage was the big tank, but no need to run the noisy pump at night.
Click to expand...

I can't see how that would work on a Webasto or Eber system as they are fed under pressure and flow to give the correct burn rate relating to demand from the thermostat .
 
Dougal Tolan said:
Heaters take a mere dribble compared to an engine. At all stages of an engine's fuel supply there is spare fuel, thats what all the returns are about. The lift pump can pump more than is required. So, there is spare fuel available.
But! If the engine pumps only operate while the engine is running, or are noisy then what ya gonna do for heat at night when the engine is stopped?

Best add another (or tee off) the tank outlet, a silent pump and another (spare) filter.
Click to expand...

My warning about not doing this was not aimed at fuel starvation but more about the potential for the engine fuel system to draw in air and airlock. It is is only a chance of course but if it did happen Sod's law would ensure it was at the worst possible time.
 
Dougal Tolan said:
Heaters take a mere dribble compared to an engine. At all stages of an engine's fuel supply there is spare fuel, thats what all the returns are about. The lift pump can pump more than is required. So, there is spare fuel available.
But! If the engine pumps only operate while the engine is running, or are noisy then what ya gonna do for heat at night when the engine is stopped?

Best add another (or tee off) the tank outlet, a silent pump and another (spare) filter.
Click to expand...

I wasn't meaning the main fuel supply to engine is sensitive ? Was referring to the Eberspacher supply. It would just be silly to take the fuel supply from here. It's always taken from a static fuel tank supply.
 
The correct way is to use a separate dip tube (standpipe) this should be 2mm bore as should the rest of the fuel delivery tube. These little pumps don’t like pulling fuel up through the larger bore stuff used to supply the engine, genny etc, as has been said the pump should be mounted as close to the tank as possible as the prefer blowing to sucking. We have had a few very early failures of the new quiet pumps (DP42) due to improper fuel extraction, usually extraction via a spare 6 or 8mm dip tube on inland craft. My post and most others are assuming the standard small forced air evaporator types of heater but as the OP alludes to manuals specifying separate tanks and return lines perhaps we are barking up the wrong tree and the OP was talking about the larger pressure jet models or some other?
 
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