Strange Eberspacher (Airtronic D2) problem

[fredrussell]

In the spirit of full disclosure this is actually a fault on my campervan's heater, but I'm hoping someone on here might have had a similar fault on their boat heater so...

When I start the heater, it goes through all the normal start up procedures, then shortly after the pump starts to tick lots of white smoke comes from exhaust. Heater keeps trying to light and then after 10 or so seconds gives up (pump stops ticking) and goes into purge mode for a minute or two.

Now here's the weird bit. If, during the period when white smoke is coming out of exhaust, you switch of the heater, the fuel pump stops ticking (as it should) but then you can hear the combustion begin and continue until whatever residual fuel is left in combustion chamber after failed start-up attempt. When all residual fuel is burnt up heater switches itself off (as it should) and goes into purge mode.

Its all very strange. I've replaced the glow pin gauze, and run heater on kerosene for an hour to de-coke it, but problem persists.

Any ideas would be welcome. I know there will be a chorus of "this is why I avoid eber/webasto etc" comments, but in fairness to the unit, its run for 10 years faultlessly - and used a great deal I might add - running most days during winter keeping the dog warm (van is work van as well as camper).

 

[rob2]

I doubt one can hope to diagnose by correspondence, the written word lacks something of the actual experience. I also doubt that the paraffin will have helped as you say it is not igniting long enough to reach running temperature. The sequence you describe made me think of a failed flame sensor - and the unit is of sufficient age to need the odd replacement part. I believe the flame sensor doesn't come into the reckoning until the unit has gone through start up and should be heating up. I suggest you take a look at the Le Tonkinois website, you'll find the resistance values for functional sensors and other diagnostics.

Rob.

 

[Big John]

In the spirit of full disclosure this is actually a fault on my campervan's heater, but I'm hoping someone on here might have had a similar fault on their boat heater so...

When I start the heater, it goes through all the normal start up procedures, then shortly after the pump starts to tick lots of white smoke comes from exhaust. Heater keeps trying to light and then after 10 or so seconds gives up (pump stops ticking) and goes into purge mode for a minute or two.

Now here's the weird bit. If, during the period when white smoke is coming out of exhaust, you switch of the heater, the fuel pump stops ticking (as it should) but then you can hear the combustion begin and continue until whatever residual fuel is left in combustion chamber after failed start-up attempt. When all residual fuel is burnt up heater switches itself off (as it should) and goes into purge mode.

Its all very strange. I've replaced the glow pin gauze, and run heater on kerosene for an hour to de-coke it, but problem persists.

Any ideas would be welcome. I know there will be a chorus of "this is why I avoid eber/webasto etc" comments, but in fairness to the unit, its run for 10 years faultlessly - and used a great deal I might add - running most days during winter keeping the dog warm (van is work van as well as camper).

Water in the fuel?????

 

[pvb]

When I start the heater, it goes through all the normal start up procedures, then shortly after the pump starts to tick lots of white smoke comes from exhaust. Heater keeps trying to light and then after 10 or so seconds gives up (pump stops ticking) and goes into purge mode for a minute or two.

Now here's the weird bit. If, during the period when white smoke is coming out of exhaust, you switch of the heater, the fuel pump stops ticking (as it should) but then you can hear the combustion begin and continue until whatever residual fuel is left in combustion chamber after failed start-up attempt. When all residual fuel is burnt up heater switches itself off (as it should) and goes into purge mode.

If ignition doesn't happen properly on start-up, the D2 should go into a second pre-heat phase, in which the fan and glow plug are on but the fuel pump is off. It should then have a second go at starting by switching the fuel pump on again. Have you left it to see what it does on its own?

 

[Porthandbuoy]

Hopefully a daft question as you've been using the heater for years, but you aren't just 'turning it off' by killing the 12V supply are you? They must go through their shutdown sequence to clean the glowplug and combustion chamber of any residual fuel.

It sounds as if the Eber has too much fuel in the combustion chamber on start up, which is odd. If you do get it going can you check the heater is going through its shutdown procedure properly? ie. pump stops, glow plug turns on, and fan continues to run for a few minute. Checking the glowplug is easy, just keep an eye on battery volts or current. If the volts drop / current goes up for several seconds then its working.

 

[pcatterall]

Hopefully a daft question as you've been using the heater for years, but you aren't just 'turning it off' by killing the 12V supply are you? They must go through their shutdown sequence to clean the glowplug and combustion chamber of any residual fuel.

It sounds as if the Eber has too much fuel in the combustion chamber on start up, which is odd. If you do get it going can you check the heater is going through its shutdown procedure properly? ie. pump stops, glow plug turns on, and fan continues to run for a few minute. Checking the glowplug is easy, just keep an eye on battery volts or current. If the volts drop / current goes up for several seconds then its working.

Agree with the above. I have had that symptom several times when bench testing heaters. For some reason the heater is not burning the fuel correctly so it shuts down and can go into purge mode. When the next cycle starts the heater in question may then fire up for a few seconds as it burns any fuel that may still be inside, the pump then starts and the extra fuel is just too much for the hater so it will fail again.

It sounds like your heater is doing all it should to start and run, my inclination would be to strip it out and give it an internal clean out. The inner 'gasket' will certainly need replacing.

 

[fredrussell]

Thanks for all the replys guys. After putting out all the white smoke there's an audible click from Heater as it gives up on the start up attempt. Tranona- I'm pretty sure it's only attempting one start up attempt, not two as you suggest.

Pccatteral- i have stripped it down once recently- was pretty damn clean inside as I'd just done the hour on kerosene treatment.

I may just bite the bullet and send it to an eber place to have it diagnosed.

Porthandbuoy - will do as you suggest, cheers.

 

[bubblewrap]

there is a small air hole in the side of the screen cavity make sure it isnt blocked with carbon, if you suspect the ecu is faulty you can get it repaired at www.ecu-repairtech.com