Eberspacher espar hydronic s3 d5e cs control unit ecu 12v genuine eberspacher warranted replacement part eberspacher d5e hydronic cs version only technical support and additional products available from butler technik suitable for the following eberspacher hydronic heater 252993050000 d5e 12v cs applicable fault codes that could require replacement ecu. P000120 064 - flame sensor interruption* p000121 065 - short circuit in flame sensor* p000301 090 - control box defective p000302 090 - control box defective p000304 091 - control box defective p000305 096 - control box defective p000306 098 - control box defective p000330 092 - control box defective p000331 093 - control box defective p000332 099 - control box defective *fault indicates multiple components should be tested prior to ecu replacement.
