It's monday yippie yi ki ay! Anyway I have a 2008k with 8000 hrs. It's giving a low flow error in dialysis only. Dearation brushes have been changed. All pressures are good, condo is good but the temp is low (29.1). I've put a new flow pump head on and also changed cfs #10. I pinched off the incoming tubing to the flow and dearation motors, and they don't slow down and the pressure bounces right back up. Any ideas?

Have you tried a deaeration pump head?

Yes, I replaced the dearation pump head

I am having the exact same problem except mine is intermiitent. Low flow error in dialysis only, the flow indicator drops to the bottom and the temperature goes low. The conductivity stays normal. The pumps are running.

I tried a new CFS.

Check in debug #2 VERR is it at 255 that is max and means you have a valve error. Any time you have a Flow Error the voltage is shut off to the Heater Rod so the temp will drop out, and when you do not have the correct temp and Cond the mach goes into bypass no flow thru the hansens. Use you Troubleshooting Guide and follow carefully make sure that you awnser all the questions correctly. Good Luck and let us know what resolved the problem.

You could have a leaking valve on your BC, making your switching time too long.

I forgot about the heater shutting down with a flow error. Most of the time when I have a flow error, the conductivity goes to 17.

In my case VERR is 0.

I honestly think Fresenius could use some better technical writers. This flipping back and forth through the troubleshooting book is an unnecessary hassle. I thought Cobe/Gambro books were more well written.

Similar problem once. Ended up being water inlet valve 41. Let us know when you crack it.

Still haven't figured it out. I have good pressure on both motors with 2 new pump heads and brushes changed. I have replaced cfs 10, valves 24,25 ,26. I followed the troubleshooting guide and it just led me in a circle back to the beginning. I guess I'll try replacing valve 41 even though I have 19 psi. BTW flow error = 1 valve error = 0 and filact = 0. No flow error in rinse or heat disinfect. Next I'll move into replacing sensor then function then actuator cables then the boards themselves. thanks for the ideas.

After two days in the tech lab, headed for the floor.

My suggestion is to skip over to section 19 of the troubleshooting guide (page 96), and perform the balance chamber leak test. I recently have had two flow problems and a conductivity problem which turned out to be torn membranes.

well I tried doing this test and I followed the instructions exactly as written. But instead of 2 cycles of 31ml each 3 distinct cycles came out with no drips in between This happened on both the spent and fresh side. ??????

Did you make sure you primed the line before taking your output samples? I usually prime for one minute prior to taking my samples. Try running the test again after priming for one minute, then post your volumes for the fresh and spent sides. Good Luck.

In my experience, most or all of the constant flow errors I've seen caused high conductivity. Verify that the 3 micro switches in your shunt door is not stuck. I kinda recall I had a really weird flow problem about 2 years ago and it turn out to be a bad micro switch in the shunt door.

it could be diaphram or could be check also Orifice