View Full Version : Espar Despair

10-10-2013, 09:52 PM
First let me thank all of you for the plethora of information on this site. I have been reading the aux heater/espar stuff looking for my answers, but have not had much luck. So here goes my first post:
I have a 2004 10 passenger 144 with the Espar D5 from the factory. I don't think it was used much by the previous owner (USAF). The van is new to me and last spring I was able to get the heater booster to kick over with the engine running, though with lots of white smoke. I have never gotten it to start with the engine off using the 7 day timer. After this summer it doesn't appear to work at all. Using the timer with the engine off, I get the cabin blower to come on and I can hear the fuel pump priming, then after a minute, nothing happens. The fan just continues to flow and the heater doesn't fire. Ocassionally when I try the timer, the fan blower will only come on for about two seconds, then shut down. If I try the heater booster now, I just get fuel pump priming noise and then nothing. I have tried to use the timer to pull the codes without any luck. Turns out the diagnostic wiring goes to the Van ECU instead of the timer ecu? My dealer charges $95 just to plug it in to their tool. I am trying to avoid that. I have tried to unlock the heater timer ecu and still no luck at getting the heater to start. I know I have the aux recirculation pump to replace (a common issue), but the heater should still start up and over heat even without this pump working. True? The Thermoking dealer nearby (hour drive and another country away) said they would be willing to run a diagnostic check on it directly from the heater, but they warned me that some parts/issues are Mercedes/Dodge. For now my plan would be to replace the pump and see if that helps. I have checked battery voltage, fuel level, and coolant level. I can see fuel moving and smell it at the heater when the fuel pump is priming. Any other help or suggestions out there? What should my next steps be? Anyone else have these same issues? Thanks again!

10-10-2013, 10:20 PM
First - Welcome to the forum!

If you haven't done so, grab a copy of the Service Manual here: http://sprinter-source.com/forum/showthread.php?t=26431
Chapter 24 has a section on the cabin heater.

You can find some manuals for the Espar: http://sprinter-source.com/forum/showthread.php?t=13601&highlight=espar+files

Without the electric coolant pump, the Espar heater will not run, but it will run with the engine running, provided that the vehicle is moving above 5 mph and you use the supplemental heater control switch (not the 7 day timer) that is below the A/C control switch. There are three switches on the far right control - A/C (top), Supplemental Heat (middle, with squiggly lines) and REST.

You can also re-wire the 7 day timer to read the diagnostics of the Espar: http://sprinter-source.com/forum/showthread.php?t=24416


10-10-2013, 11:23 PM
Bruce, that's the first time I've ever heard that 5mph reference. I had come to the conclusion that mine didn't work, but I've only ever tried it idling in the driveway. I'll have to try this tomorrow. If I get up to speed and then stop to get out and have a look in the wheelwell, should it stay running at idle, providing that the engine is not yet up to operating temperature?
Thanks for the new idea,


10-11-2013, 12:15 AM
Yes, it will stay running - this is only for the supplemental heater mode, not the 7 day timer mode. Also make sure that the temperature control is turned up to the upper range. It will shut off of it is on the lowest setting.

This is the paragraph from the service manual:
The supplemental cabin heater only operates when the engine is running, the mileage exceeds 8 kilometer (5 mph) and the fuel tank volume exceeds 1/8 of a tank. The heater should start if the coolant temperature is below 40 C (104 F).


10-11-2013, 01:04 AM
Replace the pump, they are the failure point. The bosch pump can be had for $100 or so and is very easy to replace. You'll greatly appreciate the ability to use the 7 day timer.


10-11-2013, 02:52 PM
Hi Chad, on my 06 with just the heat booster it would run as long as the engine was running and would even run till overtemp cut out if the elec ciculator had packed in. Happened. You don't say where you are but these units are very sensitive to corrosion ie road salt. Its very important to cycle the heater at least monthly to keep things moving (engine temp to normal). Internal blower can seize up. What idiot designer put the unit behind the headlight where it gets road spray? On start up blower comes on first before it fires.
Attached are some files I found that may help.
I had to replace my espar and found a generic truck (D5WSC) unit on ebay for half what the oem unit ( $1.2-1.5 K ) is. My unit had a seized blower and corroded internal wiring. It was not plug and play but in my case I had already done the the run without engine running hack, so no problem. There are rebuilt units coming out of Europe very cheap but what warrantee.

10-12-2013, 01:33 AM
First of all I would like to say I love Eberspachers. Secondly I would like to say Eberspacher electronics are dreadful,in as much as comms are hit and miss and ther are so many variations depending on manufacture. A good sign is that the pump is ticking,means it's not locked out yet,so go for the combustion fan and glow plug.Fan has to reach speed and glow plug has to...glow.Take off the square black cover on top of the fan and make sure it spins.If its free and it doesn't start you have to strip it down and maybe renew the brushes or replace the glow plug ,either way you have to strip it.Soak all the screws in penetrating oil before hand,vapour from the battery helps to destroy the aluminium casings.The start up procedure is water pump on,fan on,glow plug then fuel.