Does diesel central heating need its own separate fuel line?

[Guest]

Thanks folks. What a great help you all are!

 

The fuel filter on our boat only has a single inlet and outlet, so I can't use that, although I could always fit a different filter of course.

 

I quite like the idea of a separate tank. There's plenty of room for one under the right hand seat on the stern (it's a semi-trad), so it would be easy to do. I might

well look into that.

 

Thinking of tank size, can anyone say roughly what sort of fuel consumption you get from a diesel c/h system please?

 

Don't forget if you have a tank dedicated to supplying your domestic installations you can entirely legitimately declare the diesel you put in it as 100% domestic.

 

(though I guess technically you should claim a lesser domestic proportion on the fuel that goes in your main tank to compensate )

Edited October 10, 2015 by MJG

[Joe the plumber]

Thank you. I think a plan is forming.

 

I must ask, going back to Bottle's post (No.14, on page 1), an "agglomerator"? Do you mean its own fuel pump? If not, could you elaborate a little please? Thank you.

[Alan de Enfield]

Thank you. I think a plan is forming.

 

I must ask, going back to Bottle's post (No.14, on page 1), an "agglomerator"? Do you mean its own fuel pump? If not, could you elaborate a little please? Thank you.

 

An agglomerator is basically a water / diesel separator.

 

http://www.asap-supplies.com/brands/cav-type/cav-type-fuel-separator-302004

[nb Innisfree]

I thought that "Mike" might have been the name of the very little dwarf

Everybody should have one, he's indispensable.

[Joe the plumber]

Thanks again Alan. I looked it up on Google and became even more confused than normal!

[raymondh]

We have seperate tank for heating and run the heater on Kerro as its cleaner and cheaper than "red"/gas oil

Heater now 7 yaers old/ running, 6000 hours never had a service! runs fine will do a strip down and service when it fails

Oh its a Webasto 90S

Ray

[NMEA]

Taking fuel other than in the instructed way, i.e. through a 2mm bore standpipe and 2mm tube for the entire fuel system is the best way to give the system a good chance of reliability and performance. Other methods work sometimes and sometimes not. However if they work it is because the installer has "got away with it" rather than done the job right. It may also wok but is putting undue strain on the pump. If it is a new heater then non compliance could affect the warranty (as could any deviation from the instructions), that's instruction not guidelines or ignore this if you think you know better manual. The latest very low pulse volume quiet faster ticking pumps are even more subject to issues caused by deviation. An anecdote for you, I have had to go and replace the fuel pump on a recent non compliant install (not done by me & it has the low volume pump) after already supplying two for self fit. In order to prove it was the install and not the pumps at fault I decided to temporarily install a compliant delivery system from a temporary tank, all has been well since then, it will be necessary to do the job again at the owners expense, fortunately I have been very sympathetic over this and the previous pump replacements or it could have been a very expensive outcome. It's not difficult to install a standpipe, even in a tank wall if the top is inaccessible or forms the rear deck, takes me about 15 minutes even having to tap a tank wall. Grease on the hole saw or drill & tap (as mentioned earlier in the thread) goes a long way to mitigate swarf ingress and I have never had an issue related to that, and I've done one or two! In short manufacturers don't write these manuals for a joke, they don't do it to make life hard, they do it to give the best possible chance of reliability and performance of their product. Deviation as I said may or may not work but doing it right works properly first time, every time.

Sorry, didn't answer one of the OPs questions, a return line is not used in the type of small heater fitted to nearly all narrowboats, that's the preserve of larger pressure jet boilers used on some widebeams & barges.

[peterboat]

my wispergen runs of the main tank it is teed from after the fuelguard filter never had any problems with it.My bubble at the front of the boat has a separate tank i run it on kero as its cheaper and cleaner

[Joe the plumber]

Fear not NMEA, I'm not about to spend a packet on some heating kit and then ignore the instructions!

 

It is tempting to fit a separate tank for it though, as long as I can arrange the supply line to sit in the correct orientation

(having looked at the Eberspacher data sheet an earlier poster linked to).

[John V]

I have been reading this thread with interest as I have just fitted diesel central heating in Sabina H (Bubble PJ system)

It has gradually dawned on me that my fuel tank is a bit different to narrow boat types ......all this talk of standpipes had me confused.

I take it, from reading the thread, that the normal narrow boat system draws by a vertical pipe passing through the top of the fuel tank (or the side near the top) that ends at a pre determined height above the bottom of the tank.

Is this universal ?

 

On Sabina H the only connections on the top of the tank are the inlet and vent pipes and the top of the electrical fuel gauge. The fuel take off (for everything) is via a branch manifold drawing from a stub pipe on the side of the tank about 2" above the bottom with individual stop valves for engine and generator (which I Tee'd for the new units, the generator being reduced from 15Kw to a new 5Kw unit at the same time)

On the bottom of the tank there is a sump section holding a gallon or so with a drain valve for getting water out.

This is similar to most of the type of working boats I am familiar with.

 

ETA the returns for generator and engine are separate and return on the side of the tank about 1" from the top (no return req'd for PJ)

Edited October 12, 2015 by John V

[Grebe]

Can we clear up an issue about using the spare outlet on he filter housing that has been bothering me.

 

If the engine is stopped, but the heater is drawing fuel from the filter housing, is there a good chance that the heater could drain the filter housing? assuming no gravity feed effect.

[GUMPY]

Can we clear up an issue about using the spare outlet on he filter housing that has been bothering me.

 

If the engine is stopped, but the heater is drawing fuel from the filter housing, is there a good chance that the heater could drain the filter housing? assuming no gravity feed effect.

The filter being discussed is the one before the lift pump so no chance of it emptying if it did the emgine would do the same.

[bottle]

In answer to John V post # 35

 

 

Is this universal ?

 

No, mine is as per yours, a take off at bottom for the engine.

 

The Erbaspacher was going to be:

 

a vertical pipe passing through the top of the fuel tank (or the side near the top) that ends at a pre determined height above the bottom of the tank.

 

but I had a separate tank fitted and those holes were plugged.

[Joe the plumber]

Bouncing my old topic back up, is it possible to have a separate heating fuel tank situated above the engine compartment (ie with its bottom at the same level as your feet when steering) feeding an Eberpacher Hydronic 5 D5WSC which is mounted perhaps 10" below the bottom of the tank in the engine compartment?

 

If so, I assume the fuel standpipe would need to come out of the upper side of the tank and the pipe drop below the bottom of the heater unit and back up into it so that the unit isn't being gravity fed.

 

Thanks for any advice, as always.

[Alan de Enfield]

Bouncing my old topic back up, is it possible to have a separate heating fuel tank situated above the engine compartment (ie with its bottom at the same level as your feet when steering) feeding an Eberpacher Hydronic 5 D5WSC which is mounted perhaps 10" below the bottom of the tank in the engine compartment?

 

If so, I assume the fuel standpipe would need to come out of the upper side of the tank and the pipe drop below the bottom of the heater unit and back up into it so that the unit isn't being gravity fed.

 

Thanks for any advice, as always.

 

You could still get a siphon effect unless the eber inlet is higher than the fuel level.

 

Having a point in the pipe that is lower than the eber will not stop a siphon. Try it with a bucket of water and a hose pipe.

[LEO]

Hi,

 

I have a 50 gallon diesel tank which supplies a Kabola OD4, this is connected to the fire by a gravity feed and the line has a fuel filter and a 'ON/OFF' tap in it.

 

Works very well and fire runs continuously for weeks on end, supplying hot water and 1 rad on a unpumped circuit, with the fire running on an minimum setting (48ft tug style boat). It also had an 'Eco Fan' running.

 

I reckon the fire burns about 3 litres a day.

 

I also have 100 gallon fuel tank for the engine and if necessary can hand pump from this tank into the diesel heating tank.

 

Maintenance - clean the stove out well once a month, change the fuel filter annually.

 

Simples!!!

 

L

[Phil Ambrose]

or

 

separate tank, dedicated agglomerator , dedicated filter and able to declare 100% domestic for that tank.

 

I did this.

Phil

[nb Innisfree]

When I fitted our Mikuni the instruction stated the pump should lift the fuel. The only way to achieve that is to mount the heater and pump above the top of the fuel tank which is impractical on a cruiser stern, so it has to be fitted below the top of fuel tank and fuel level.

[Flyboy]

Your fuel filter would commonly (depending on type) have two 'inputs' & 'outputs' of which one will be blanked off, simply remove the blanking screw and screw in the pipe from your heater system. Job done, no drilling and no swarf.

 

Whoever fitted that filter element seems to have installed it upside down.

[Joe the plumber]

Thanks folks. On our (semi-trad) boat, I couldn't see a way of getting the fuel supply from lower than the heater unit, hence I've been thinking about a separate tank.

 

I think I may have another idea for where a tank could go now though, at the side of the engine directly below the heater unit. I'll have a bit of measuring to do this morning.

[Joe the plumber]

A further thought. I've space under a single bed directly the other side of the engine compartment front bulkhead. Is there any reason I can't have a heater diesel tank there, filled from (and vented to atmosphere via) the engine bay side?

[nb Innisfree]

A further thought. I've space under a single bed directly the other side of the engine compartment front bulkhead. Is there any reason I can't have a heater diesel tank there, filled from (and vented to atmosphere via) the engine bay side?

Providing it's constructed from correct materials, securely fixed in place and it ejects any fuel out of the boat if overfilled I can't see any prob.

[Joe the plumber]

Thanks, I was thinking of having one made from stainless steel with feet to screw it down to the boat floor. An overflow pipe shouldn't be a problem, although the tight ar*e in me would prefer it if I could catch the fuel to re-use!

[nb Innisfree]

Thanks, I was thinking of having one made from stainless steel with feet to screw it down to the boat floor. An overflow pipe shouldn't be a problem, although the tight ar*e in me would prefer it if I could catch the fuel to re-use!

Some grades of ss need to be exposed to oxygen to prevent corrosion so you need to research that. As for overflow, the filling point must be designed so that any fuel ejected from that

point must be prevented from entering the boat in any way.

[NMEA]

Best advice is to just read the manual, most of these heaters will tolerate the heater and or pump being a bit above or below the tank and the precise parameters are given in the install instructions, most will also tolerate the heater being quite a long way from the tank, up to 8.8m and up to 3.3m above the tank & after the dosing pump in fact, though the fuel line to pump measurement should be kept to under 1.2m. Generally the pump should not be above the heater though. It is also worth noting that solenoid dosing pumps when at rest are a shut off valve, though it doesn't hurt to fit a valve also.

Edited November 15, 2015 by NMEA