"low flow error" during normal dialysis opperations in dialysis mode the flow indicator completely stops. tmp and coductivity runs high too, so upon by-passing opening the shunt door for 5 mins.
then it goes back to normal for another 30 to 45 mins. then the problem resurfaces, upon using the trouble-shooting guide from
Fresenius 20008h model and re-placing recommended boards together with suspected valves still wont solve the problem.

Have you tried replacing the flow motor, deair motor or the CFS transducer?

Actually not replacing the motors but checked their pressures, its in thier reccomended values, and also re-placing the cfs did not work. I can see the flow pump is running from its shaft, but I can hear that it tends to change the sound, maybe the pressure from the pump head on foward gets stuck somewhere.

Here are some things I have found that may cause Low Flow Errors...
- Occurring with high tmp's, a faulty Act bd that is causing V25 to chatter.
- A bad or stuck float switch
- If hydroblock was drained (during service)along with a faulty float switch.
- V41 becomes intermittent when hot and does not open completely. Ohm coil out (30-80 ohms)
- flow pumphead
- A faulty cfs 10 as mentioned, also if unplugged will cause flow errors.(more likely on early model H machines.)

Good Luck...

posted by:
Chuck & Nephrotech,
I agree with your replies on all the suspected areas of where the problem rises, just this morning a flow inlet error showed on the display, follwed by a low flow error,
In heat rinse, A flow recirc error shows too on the display, since I dont have some parts on hand now, thanks for the help.

Sounds like a pumphead

I know the answer to this problem exactly . I had it happen several times. The problem is V24. Just change it, and your problem will go away. Don't be looking at board problems . 99% of the problems with these machines are valves, a sticky float ( which I now remove every 3 months and clean) and the occasional CFS . I also do a TMP cal every 3 months, just in case. This eliminates self test failures. Trust me, V24 is the solution to your problem.

Re : post by new member " Brown "

error # Flow recic error1.
This is caused by a worn out deaeration pump. I just had the exact problem occur last week, and the de-air pressure was above 0 when it was in disinfect mode. The machine worked great in dialysis and rinse, but I would get this error in heat mode. A new pump head fixed it perfect. Good luck.

Thanks to all of you for being good friends and for helping, I believe and trust that we have the same methods and techniques as problem solvers. And this was the problem, in the shunt door, there are caps red and blue, indicating the fresh and the spent, I found one of the caps stuck inside the fresh side of the dializer connectors. Our nurses will always stick to their famous answer."I dont know" when asked of how the caps got into the connector. But I think that somehow when one of those mysterious nurses opened the shunt door to hook up the dializer that cap came falling off, so instead of putting it back where it came, she ended up putting it in the connector, wich eventually cuts off the flow.