Eberspacher Hydronic trouble shooting guide

PF Jones a fully authorised Eberspacher Repair centre

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

 

Our staff are trained by eberspacher in all aspects of  both fitting and repair.
 
 
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We have over 3000 eberpacher parts on the shelves.

Including Airtronic and Hydronic Units

TROUBLESHOOTING FOR Eberspacher hydronic 4/5 HEATERS

 

TROUBLESHOOTING FOR Hydronic 4/5 HEATERS
(“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. Coolant pump is not pumping  

1. Check voltage on heater’s harness on the heater’s side (pins 1 and 2 on heater’s 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, then try to start the heater by connecting red and yellow wires together by a wire jumper (chambers 2 and 11 on 7 day timer connector – make sure that you have +12 or +24 volts on the red wire). If the above helps, replace switch or timer
     
   

3. If the heater still does not start, then the most likely ECU is locked or the start-up self test fails.

Use 7-Day Timer, EDiTH or Diagnostic tool to retrieve fault codes from heater’s memory and unlock ECU if it is locked.  Follow heater’s manual for the fault codes description and repair methods
     
Being turned on, heater just pumps coolant, never stops and never performs a start attempt. No fault codes found in memory  

1. Check and replace temperature sensor.

2. If the sensor is good, replace ECU

     
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.
     
Heater switches into shut-down phase 20 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 2 on Hydronic 4/5 connector). Turn the heater ON and make sure that the voltage is still OK. Repair harness and connections if necessary.

     
Heater makes two attempts to start with no success and then stops completely. No smoke comes from the exhaust pipe, some smoke can be seen between the exhaust pipe and heater  

1. Check if exhaust pipe is not plugged with ice. 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 # 5 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 and replace atomizing screen. 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 the flame sensor.
2. Replace ECU if flame sensor was good.

     
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.
     
Heater overheats and stops soon after being turned on. Temperature of the heat exchanger raises quickly after start.  

1. Bleed air from the coolant lines and heat exchanger. Check plumbing for no restrictions for coolant flow.
2. Check if the coolant pump spins. Unblock and clean it if necessary.

     
Heater does not provide enough power mostly working on low power level which can be detected by measuring electrical current draw.  

1. On old installations - check coolant pump
2. On new installations - Too big resistance for coolant flow.
Possible too many units like heat exchangers are connected to the heater serially.
Check plumbing. Reconnect system’s heat exchangers in parallel which reduces resistance for coolant flow.

     
Ground wire burned out  

Vehicle’s starter was turned on or short circuit happened in vehicle’s power circuits while vehicle’s power switch in the ground battery wire was turned off. Fix the wire or replace ECU.

   *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