Eberspacher Airtronic fault finding guide

PF Jones a fully authorised Eberspacher Repair centre


Eberspacher Airtronic fault finding guide, follow the trouble shooting steps detailed to diagnose the common faults for all eberspacher airtronic models


Our staff are trained by Eberspacher in all aspects of both fitting and repair.

With over 8 years experience, and thouands of hours hands on experienece.

PF Jones are able to handle any eberspacher inquiry speedly and promptly

We have over 3000 eberpacher parts on the shelves.

Including Airtronic and Hydronic Units


View our range of Eberspacher Airtronic Heaters

If you are looking for the eberspacher fault codes they can be found at Eberspacher Fault Codes


(“No start” and “Heater Stops” conditions)

Use these recommendations in conjunction with Fault Code List and heater’s manual

Description of the problem

  Possible reason and method of repair*
Absolutely nothing happens when the heater is turned on   1. Check voltage on heater’s harness on the heater’s side (pin # 1 and 10 on Airtronic connector). Turn the heater ON and make sure that the voltage is still OK. Repair harness and connections if necessary.
    2. If the voltage is OK, than try to start the heater by connecting together red and yellow wires on control branch of the heater’s harness. Make sure that you have +12 or +24 volts on the red wire on the control branch
    3. If the voltage is OK but the heater still does not start even if red and yellow wires are connected to each other, then the most likely ECU is locked, bad, or one of the startup self tests fails
    Use Diagnostic tool to retrieve fault codes from heater’s memory and unlock ECU is it is locked.  Follow heater’s manual for the fault codes description and repair methods
Being turned on, heater turns blower a few times, FMP and ECU’s relay may click one time but heater would not make an attempt to start  

1. Bad electrical connections. Check voltage like described in case #1

2. Start-up self test failed. Retrieve fault codes from heater’s memory using Diagnostic tool or EDiTH, refer to the heater’s manual for the description and repair methods
Heater switches into shut-down phase 20-25 seconds after being turned on (the most likely, fault code 11 found in memory)   Check voltage on heater’s harness on the heater’s side (pins 1 and 10 on Airtronic connector). Turn the heater ON and make sure that the voltage is still OK. Repair harness and connections if necessary.
Being turned on, heater just blows cold air, never stops and never performs a start attempt. No fault code recorded.  
  • Was “Ventilation” button pressed instead of “Heat”?
  • Replace combo Sensor
  • Replace ECU if necessary
Heater makes two attempts tostart with no success and then stops completely. No smoke comes from the exhaust pipe, some smoke can be seen between the exhaust pipe and heat exchanger.  

Reroute it if this is the case for not having it to be U-shaped

2. Check combustion air intake pipe. If the exhaust and combustion air intake pipes are OK, see case #6 below
Heater makes two attempts to start, may smoke for a while and then it stops  

1. Do the fuel quantity check, if the amount of fuel is insufficient, than check the fuel pick-up pipe, fuel lines and connections, fuel filter on the pump, replace the filter or pump if necessary.

2. Check the glow pin, clean ventilation hole and replace atomizing screen.

3. If necessary, take the heater apart, clean combustion tube (including it’s all air ways) and the heat exchanger
Heater makes two attempts to start, then stops. Both times it sounds like the ignition takes place and then combustion process stops together with the fuel metering pump. Usually no smoke comes from the exhaust pipe just like when the heater starts normally  

1. The heater ignited but the flame was not detected. Check and replace combo sensor.

2. Replace ECU if combo sensor was good.
Heater ignites normally, goes into boost mode, then switches to stand-by mode, blower is slowly spinning but the heater never restarts. No fault code recorded.  

1. Using EDiTH, check setpoint for temperature and current air temperature. Replace part which works improperly. Swap minicontroller if do not have EDiTH;

2. If minicontroller OK, install external temperature sensor or replace ECU
Heater ignites normally, but often stops (codes 52-56 found in memory)  

1. Check fuel lines for gaps in connections inside connection pieces

2. If the heater stops only when the vehicle is in motion, reroute combustion air intake and exhaust pipes, or bend their ends toward to the rear of the vehicle

   *To avoid inefficient expenses, it is strongly recommended to have the heater diagnosed by specialist before replacing expensive parts


More information on Eberspacher Heating Systems


I have a VW t5 Campervan, 2015 model with an eberspacher heating system. On a recent trip to Scotland it stopped working after about 2 hours.Leisure battery was fully charged when I stopped having driven for 350 miles that day. Next day and every other time I have turned it on it works fine ( for short periods ) I did have the temp. set at 25 degrees and it was very cold ( 1-2 degrees ) How long should I expect to be able to have the heater working off the leisure battery ? Most times I expect to be plugged into an electrical source and I presume heater would keep working. Any advice would be very welcome.
Hi, I have the Eberspacher Combitronic heating/hot water system. The problem is my heating. The fan matrix is the CT03MD.
When connected to 240V everything works fine and I have nice hot air throughout, however when I switch to diesel only power, the fan matrix does not fire up. The water heater sparks up and heated water circulates through the matrix but the fan just does not start. I cannot find a tech manual on the fan matrix so am not sure which readings i should have where.
I am not sure if it has ever worked correctly because when I tested it I did not realise it will automatically draw from the 240v if connected!
If i switch to diesel from 240v the fan slows down very slowly until it stops. When switched on the diesel heater continues to burn and does not switch itself off when the fluid is very hot. (This stops ok when heating domestic water). There is 12v DC at the fan matrix, it is not powered direct from a battery as I have a 24v system, so i use a Victron voltage dropper which puts out 13v and 25A, surge to 35A.
Any advice, assistance greatly appreciated. If you have a tech manual that would be great. Can you let me know how expensive the diagnostic tool is.
Hi I have seeviced and changed the blower motor due to the magnet in the blower missing can you get a new magnet?? Also the heat now works with the new one but doesn't get any hotter than 9 on the dash. What could to be??
Hi there, I have a D2 with both easystart select and easystart remote+. Unit runs fine, but does not seem to shut off at set temperature.

Fan slows but unit continues to heat.

Set temp of 18, room temp shows 27 but heater still hearing, any suggestions ?
D2 starts and runs does not get full heat it sounds like it's burning then stopping then burn again sounds like a 4x4 car driving past our vehicle
D2 airtronick 24v. On start up smokes the paddock out white smoke,
Sounds like it's going to kick into action then shuts down to slow cold blow air? Smoke stops.
Fuel good see it clicking along clear pipe into heater,
Any one had this problem if so can you help please

hi mitch
how long ago did you have the heater serviced as from description what you are saying it sounds like it could be carboned up inside the heater and burner as it is trying to start but it cantbecause it is clogged up,, a good de-coke and a service kit should cure the problem
I tried to start my heater on my van over three times and have been told after three times it locks you out.Is there a way i can get the coeds to restart the heater with out going to a dealer

I have d4 unit and have been told it has a af09 fault
Had new ecu and fan motor to my D4, but since fitting have trouble starting and running.
Normally takes at least two attempts to get it running, first attempt normally lots of smoke, everything seems ok on start up all the usual happens but just doesn't fire up.
Code 52 showing, changed diesel filter on pump, checked for exhaust blockage..none.
Now been running for 24 hours at a fairly high setting and just stopped, strong smell of diesel in cabin..bit of a noisey shut down!
Checked for water in exhaust as been heavily raining but nothing there.
Just started it up again do is running ok, any ideas, suggestions welcome.
My D3CL runs normally but after about 20 minutes working hard the fan speed becomes unstable and eventually causes a trip (Code 33). I have measured the voltage applied to the motor (with an oscilloscope) and this goes keeps dropping to zero (PWM stops) for a few seconds and then comes back again causing the fan speed to oscillate. This does not happen in cooling mode or when the heater is not working hard.

Could this be caused by a temperature sensor or is it the fan motor its self. Why does the PWM stop and start?

Kind regards


Write a review