Index: firmware/App/Services/PIControllers.c
===================================================================
diff -u -r52362c924eb6233f0a23f6978ea3ce6a2b1b9376 -rc48ea51c06c9d002f1b9b6a1d7b72d69756f183d
--- firmware/App/Services/PIControllers.c	(.../PIControllers.c)	(revision 52362c924eb6233f0a23f6978ea3ce6a2b1b9376)
+++ firmware/App/Services/PIControllers.c	(.../PIControllers.c)	(revision c48ea51c06c9d002f1b9b6a1d7b72d69756f183d)
@@ -64,7 +64,7 @@
 /// PI Controllers -- initial configurations.
 static PI_CONTROLLER_T piControllers[ NUM_OF_PI_CONTROLLERS_IDS ] =
 {   // Kp   Ki  uMax  uMin  ref meas  err  esw esum ctrl  Ilimit controller type
-    { 0.0, 0.0, 0.90, 0.10, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 50.0,  CONTROLLER_UNIDIRECTIONAL },  // PI_CONTROLLER_ID_ULTRAFILTRATION
+    { 0.0, 0.0, 0.90, 0.10, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 50.0,  CONTROLLER_BIDIRECTIONAL },   // PI_CONTROLLER_ID_ULTRAFILTRATION
     { 0.0, 0.0, 0.90, 0.10, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 100.0, CONTROLLER_UNIDIRECTIONAL },  // PI_CONTROLLER_ID_BLOOD_FLOW
     { 0.0, 0.0, 0.90, 0.10, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 100.0, CONTROLLER_UNIDIRECTIONAL }   // PI_CONTROLLER_ID_DIALYSATE_FLOW
 };