Yes we still have some 2008-D machines. I have one of these D's that whe the dialysate flow is turned up to 800 it will sometimes drop the conductivity to below 13.0. Then I turn the flow to 500 and the conductivity comes back up. It only seems to happen after the machine has been running for several hours. I checked the conductivity with an external meter and it really is going low. Please help.

try replacing the balancing chamber membranes.

Thanks for the help. It was the acid pump after it warmed up it would pump erratic.