msimms
Well-Known Member
Have a baffling problem with my Eberspacher D4. It’s 7 years old and done over 7700 hrs, it’s been mainly trouble free with maintenance limited to running 4 litres paraffin through it once a year to clean it through. Problem started a few weeks back with the heater having problems running for any length of time. I ran eight litres of paraffin through it but it still gave issues. The fault codes given off were 053, 054, 055 or 056 (all flame loss) or occasionally 052 safety time exceeded. I removed the heater and checked the flame sensor resistance but it measured okay. The glow plug gauze was replaced when the heater was out along with the pump filter (both looked fine). When the heater was put back on the boat it was giving a new fault, I can’t recall which one but it was again to do with the sensor and when I checked the resistance it was open circuit. Initial thought was that removing it and replacing it caused an intermittent sensor fault to fully fail.
Ordered and fitted a new sensor and the heater immediately fired up for about an hour before failing with fault code 065 (short circuit in flame sensor). Thought I’d got a bad sensor but on checking it’s has the correct resistance at 1K. Removed the sensor again to check for any physical damage to the cable but it’s perfect. Fault code changes to 064 if the flame sensor is disconnected from the heater.
Could only think that the control unit had failed and was misreading the sensor resistance value. Fitted a new controller and heater worked for about an hour before failing with 065 again. Tried pulling the fuse and cable to the heater numerous times in an attempt to reset it but no joy. Left the heater for a week before starting trying again and it fired up and worked perfectly the whole weekend before again failing with 065. Again tried pulling fuse and disconnecting cable but to no avail.
Any ideas if there could be some other component causing a false flame sensor short circuit? Having spent £350 on replacement parts I’d like to try and get it going.
Cheers
Mark
Ordered and fitted a new sensor and the heater immediately fired up for about an hour before failing with fault code 065 (short circuit in flame sensor). Thought I’d got a bad sensor but on checking it’s has the correct resistance at 1K. Removed the sensor again to check for any physical damage to the cable but it’s perfect. Fault code changes to 064 if the flame sensor is disconnected from the heater.
Could only think that the control unit had failed and was misreading the sensor resistance value. Fitted a new controller and heater worked for about an hour before failing with 065 again. Tried pulling the fuse and cable to the heater numerous times in an attempt to reset it but no joy. Left the heater for a week before starting trying again and it fired up and worked perfectly the whole weekend before again failing with 065. Again tried pulling fuse and disconnecting cable but to no avail.
Any ideas if there could be some other component causing a false flame sensor short circuit? Having spent £350 on replacement parts I’d like to try and get it going.
Cheers
Mark