H-machine. 42000hrs. New(er) flow and deaer motors, with 2005 pumps. tried actuator bd, cfs switch, bal chamb membranes OK. float OK. Here's where it gets weird. NO flow error in dialysis mode. NO flow error in rinse mode. When I have a problem is when I put the machine in self test! Level det. to blood leak alarm test, Flow error goes to 1 in diagnostics with cond. on its way to 17. It is not a constsant flow alarm. Also in service mode when for fun I try A valve test, my flow is constantly OFF! That's all I observe. Again NO flow errors in dialyze or rinse modes. Possible Test bd? It's an acute machine and the R.O.is fine. I can only get to the renal web every other day at best. weirdest thing I ever encountered this past week. thanks in advance.

Tech support helped me. It was a bad test board.

42,000 hrs..........wow!!!

I agree 42,000 is exteme...at that age I would check all connection inside card carge. Could be corrosion fouling up your system.