fresenius 2008H machine.hep. pump alarm keeps going off in 1 to 5 minute intervals,yet hep.screen is verifying delivery and visually hep being delivered via syringe.and this is the real kicker;happens only on second shift patient and occasionally on a third shift patient.anyone with a clue?i know i can swap out the modules but just wondering what would cause such a flukey thing like this.nothing in Fresenius troubleshooting manual!!

h

Does the patient have an unusually high venous pressure? Could that pressure be transmitted and cause problem?

I think I know the answer to the problem. I discovered it many years ago, and now it is in my quarterly inspection. Take out the pump module, and lubricate the three brass gears at the end of the shaft. Also, lubricate the internal shaft and threads that the syringe glides on. I use super lube spray with teflon ...no odors either. That should solve the problem. You might want to compare the difference before lubing and after simply by spinning the brass gear with your fingers before spraying. ( PS, keep the spray off the PCB )
Ian