Eberspacher diesel heater repair

[schrater]

I thought I'd share my successful adventure in repairing my old Eberspacher D4L diesel heater. I don't think it was original with my boat, and I don't think it was even new when it was installed. But it worked well until last month, when I all of a sudden noticed that it would shut off a few minutes after starting, and with no heat. I restarted several times with the same result.

All of the wording on the unit is in German, but I was able to find the model number (SP 200 AD 04) and find that it is a 4300W 12V air heater. I checked the thermostat, and it was definitely clicking on and off. And I could hear the fan start, so I knew it had power. I started looking around in the engine room and found the small fuel pump and could hear it running (ticking) and see fuel advancing down the line. That's when I noticed there was red diesel fuel dripping rapidly out of the exhaust line. Essentially, fuel was being pumped into the furnace, but it was not igniting, so then it was just running right back out.

This made me think of the element (glow plug). There is one protruding from the top of the unit, with two wires and the fuel line feeding into it. I removed those and pulled out the plug. It was heavily caked in soot (coke). My resistance meter connected to the two electrical points confirmed that no charge could get through. Burned out.

I manage to read the markings on the glow plug and found a place in the UK with an identical unit (BERU). They sent one over, I connected it back in, and bam, I've got heat again! However, I also got a lot of exhaust smoke into the cabin at first because there was still a lot of fuel soaked into the exhaust line, and that had to burn itself out first.

Hopefully I've extended the life of my heater by at least a few years (for only $30!), and hopefully this might help someone else find a similar solution. Good luck!

 

[Nomad Willy]

Schratter,
HaHa I've got an old E-Spar heater that came out of my old Albin. Almost threw it out several times. After your post I'll keep it around awhile longer. Could work in my 18' OB boat w an on and off function only. Thanks

 

[North Baltic sea]

Hey, the device works better when before shutting down the drive it at full power for 15-30 minutes, soot and other deposits are burnt off and the device turns on easily and does not give off smoke when you next start the burners. Another way is to burn 'petrol light "oil lamp,fuel," may be kerosine, I do not know the term US. it burns cleaner than diesel and clean the device once a year to do a good omen winter stores.


NBs
Kippis!

 

[FF]

The glow plug is a hassle as the unit as built for trucks and buses was designed to operate with 14V from the operating engine.

Start from batteries in a boat and the voltage can be too low to get a good light off.

The simple solution is to trim the nichrome wire in top of the unit at least one coil .

This will raise the voltage while dockside , and does no harm when lighting underway.

Measure the voltage when starting at the glow plug to see what you have .

 

[Wanna-b]

Thanks for the post. Just bought a boat and couldn’t get my heater to work. I will do some more investigating.

 

[NWSeadog]

Mine starts very consistently if I use Kerosene. I've even considered putting in a kerosene tank just for the heater.

FF - I don't see the nichrome wire. Is it inside the case?

 

[FF]

"FF - I don't see the nichrome wire. Is it inside the case?"

The units for larger boats X7 the coil is on top of the heater under a simple cover.

Kerosene does the best job in these heaters.

 

[Harrison Ford Transit]

D4L doesn't work properly when installed

Hello,

Great work getting your heater working! I am at a similar challenge. I do not have a boat but a van. I hope you will not scorn me... I did not find many fora discussing the eberspacher D4L and I am desperate for some thoughts.

I managed to get my heater working indoors in a test setting. It worked like a charm. When I installed it under my driver's seat however, the fan rotated only at about half speed, causing the pump to operate at half speed as well...

I got it out and connected all the wires like they were when installed it and whaddayaknow, it works again like it did indoors. Nothing wrong with any of the wires or the fuel lines I conclude.

Installed it again, same problem. Any thought as to why the heater malfunctions when installed in its proper place?? I can't see it touching the body anywhere, so no power leakage as far as I can tell.

I added a picture to illustrate the situation. In this picture it is connected to a space battery. When hooked up to the car battery it works all the same as well. I am really at a loss...
Tnx in advance for considering my problem.

 

[Lepke]

Half speed is probably low voltage. Make sure you're getting 12v and still getting 12v when turned on. It could be caused by a bad ground.

 

[Max1]

I had the same problem with the diesel heater that came with my boat. It too was an Eberspacher. It would only start up, run for a bit, exhausting huge plumes of smoke from the exhaust and then shut down. I've since disconnected it and it's sitting in a bin in the garage. I'm hoping the problem is similar to yours, and I will try to check it out in the near future. Thanks for the post.

 

[Bmarler]

The difference may be in the wire supplying power to the heater. If the run is long, and the gauge minimal, you can have too much voltage drop at the heater. I see a volt meter in the picture, poke around and see what you get.
In the startup mode it will pull a considerable current when the flow plugs are on. Your wire size needs to be able to handle that.

 

[tpbrady]

If you Google Espar you can find links to parts and manuals, for example Espar Parts of Michigan. Having had two different ones, I generally use a few expletives when one fails especially some of the dumb things they did when designing them. The last project involved replacing the flame sensor. Step one count the blinking lights and cross reference to the error message. If you don’t have an aftermarket add on that allows you to see blinking LEDs then that would be step one. Second remove the heater and virtually disassemble it to get to the flame sensor (next time I would use a Dremel to cut an access panel in the casing and save about 2 hours.

The most likely cause of smoke on startup is the glow plug. After that get a copy of the manual and start reading. There are a lot of things that can go wrong including locking you out of the heater until you reset it using jumpers across terminals if I recall correctly. You can lock yourself out of the heater simply because you tried to start it too many times and it didn’t light. My particular model, D8, is no longer in production so if some parts fail, like the blower motor, it’s a throwaway. Needless to say I am not a fan.

Tom

 

[NWSeadog]

The difference may be in the wire supplying power to the heater. If the run is long, and the gauge minimal, you can have too much voltage drop at the heater. I see a volt meter in the picture, poke around and see what you get.
In the startup mode it will pull a considerable current when the flow plugs are on. Your wire size needs to be able to handle that.

This was my problem. Low voltage to the glow plug (mine was a bad connector) will cause white smoke and failure to light. It then shuts down. There was enough voltage when on shore power that it would usually light. Not so much when at anchor.

 

[Harrison Ford Transit]

Hi all,

Thank you for thinking along and sharing your thoughts, suggestions and similar struggles. I only now got back to you as I did not find time (and courage) to try and get to the bottom of my problem. Unfortunately nothing positive to share so far.

The gauge and run of the wire are within specification, so any possible drop cannot originate there. Measuring the voltage gives me a steady 12V and hooking it up to a spare 12V battery does not solve the problem. As long as it is installed in its designated space under the driver's seat, it just quickly dies (within half a minute) after rotating the fan at decreasing speed.

What continues to puzzle me is that it works just fine when hooked up to the same spare 12V battery indoors... ��

I guess one good thing I can report is that there is no black smoke or anything like I read in some of the replies. Unfortunately I am no further yet to solving this issue. When I do I will be sure to share it here. Any new thoughts on your sides are still welcome of course ��

 

[Bmarler]

Hi all,

Thank you for thinking along and sharing your thoughts, suggestions and similar struggles. I only now got back to you as I did not find time (and courage) to try and get to the bottom of my problem. Unfortunately nothing positive to share so far.

The gauge and run of the wire are within specification, so any possible drop cannot originate there. Measuring the voltage gives me a steady 12V and hooking it up to a spare 12V battery does not solve the problem. As long as it is installed in its designated space under the driver's seat, it just quickly dies (within half a minute) after rotating the fan at decreasing speed.

What continues to puzzle me is that it works just fine when hooked up to the same spare 12V battery indoors... ��

I guess one good thing I can report is that there is no black smoke or anything like I read in some of the replies. Unfortunately I am no further yet to solving this issue. When I do I will be sure to share it here. Any new thoughts on your sides are still welcome of course ��

Is this a new heater?
Looking at your picture, the heater is laying on its side. What is the position when testing indoors and also when installed under the seat?
You say it dies within a half a minute. Did it start to fire up at all? Any combustion sounds or smoke?
Short story for you, a long time ago I had an earlier version of the espar d4. It started acting up after I owned it for a few years. Finally, it wouldn’t start at all. The fan just ran at reduced speed and the fuel pump and glow plug never came on. I took it out, disassembled it to inspect. Couldn’t find any issue. Put it back in and it runs fine for a couple of days, then it dies as before. I’m stumped. I took it to an espar dealer in Canada, a very respected repair guy there. We put it on the bench and fire it up, works fine for an hour and quit. Took it apart to inspect, put it together and it ran for another hour. Now he’s stumped too.
I took it home, decided to order a new combustion blower for it.
Problem solved. Turns out that the little motor is sealed. The carbon brushes wear and let the dust whirl around in the motor housing and eventually bog the motor down. Taking the heater out and banging it around would settle the dust for a while, but after an hour or so it would bog the motor again.
So, if the heater has a lot of hours on it, it might need a new combustion blower. It’s an expensive part though, so if you can find the diagnostic tool to see what’s happening with the controller you should.
There’s also espar software called Edith that runs on a pc through a serial interface unit. That’s what I use now.

 

[Harrison Ford Transit]

Is this a new heater?
Looking at your picture, the heater is laying on its side. What is the position when testing indoors and also when installed under the seat?
You say it dies within a half a minute. Did it start to fire up at all? Any combustion sounds or smoke?
Short story for you, a long time ago I had an earlier version of the espar d4. It started acting up after I owned it for a few years. Finally, it wouldn’t start at all. The fan just ran at reduced speed and the fuel pump and glow plug never came on. I took it out, disassembled it to inspect. Couldn’t find any issue. Put it back in and it runs fine for a couple of days, then it dies as before. I’m stumped. I took it to an espar dealer in Canada, a very respected repair guy there. We put it on the bench and fire it up, works fine for an hour and quit. Took it apart to inspect, put it together and it ran for another hour. Now he’s stumped too.
I took it home, decided to order a new combustion blower for it.
Problem solved. Turns out that the little motor is sealed. The carbon brushes wear and let the dust whirl around in the motor housing and eventually bog the motor down. Taking the heater out and banging it around would settle the dust for a while, but after an hour or so it would bog the motor again.
So, if the heater has a lot of hours on it, it might need a new combustion blower. It’s an expensive part though, so if you can find the diagnostic tool to see what’s happening with the controller you should.
There’s also espar software called Edith that runs on a pc through a serial interface unit. That’s what I use now.

Thank you for you extensive reply!! The heater is anything but new Came with my oldtimer ambulance Ford Transit from '86. I am gonna investigate today taking your considerations into account. Keeping my fingers crossed!

 

[Harrison Ford Transit]

Hello all,

I had a huge breakthrough with my Eberspacher heater! I found the problem, fixed it and now it works perfectly!!! Such a victory for me. I had been trying to get it to work for years. I still have to install the pipes to get the hot air into my van, but that's a minor job.

I want to share my problem and fix here as it might help someone else. The problem turned out to be a broken little spring inside the motor. This spring should hold one of the carbon brushed (there are two springs and brushes) in place. The carbon brush was not completely dislocated, so I guess that is why it worked occasionally.

Found a spring, installed it, assembled the heater, and bingo.

 

[Bmarler]

Terrific, glad you finally got it working. Maybe my little motor story got you thinking about the brushes?

 

[Harrison Ford Transit]

Terrific, glad you finally got it working. Maybe my little motor story got you thinking about the brushes?

Indeed it did! I figured the problem almost had to be something inside the motor as none of my test explained the malfunction.

Another clue came from a friend mentioning the importance of the positioning of the heater. Which made me realize that it was a little on its side during the positive tests indoor. Inside the van it was perfectly upright and did not work.

Apart from the clues, the comments and encouragement in this thread gave me the drive to continue my quest. Thanks to all of you for welcoming a van-driver on your boat forum