Index: firmware/App/Controllers/ConcentratePumps.c
===================================================================
diff -u -rdf0df237b2a946a1599a45d9e3585194fd550829 -rc20dacdc80635ee4370867e97aba9b00f765ae7e
--- firmware/App/Controllers/ConcentratePumps.c	(.../ConcentratePumps.c)	(revision df0df237b2a946a1599a45d9e3585194fd550829)
+++ firmware/App/Controllers/ConcentratePumps.c	(.../ConcentratePumps.c)	(revision c20dacdc80635ee4370867e97aba9b00f765ae7e)
@@ -992,17 +992,18 @@
 static void monitorPumpSpeed( CONCENTRATE_PUMPS_T pumpId, ALARM_ID_T alarm )
 {
     F32 cpTargetSpeed   = concentratePumps[ pumpId ].currentPumpSpeed;
-    F32 cpError         = fabs( fabs( getMeasuredPumpSpeedMLPM( pumpId ) ) - cpTargetSpeed );
+    F32 cpError         = fabs( getMeasuredPumpSpeedMLPM( pumpId ) - cpTargetSpeed );
     BOOL isCpSpeedOut   = FALSE;
     F32 tolerance       = CONCENTRATE_PUMP_SPD_OUT_OF_RANGE_TOL_WHEN_SLOW_MLPM;
     DG_OP_MODE_T opMode = getCurrentOperationMode();
 
-    if ( cpTargetSpeed > CONCENTRATE_PUMP_LOW_SPEED_THRESHOLD_MLPM )
+    if ( fabs( cpTargetSpeed ) > CONCENTRATE_PUMP_LOW_SPEED_THRESHOLD_MLPM )
     {
         // Check if the pump is not in the off state and if it is not and greater than the minimum threshold, divide the error
         // to target speed. If the pump is off the target speed is 0 so the speed check is done differently
         // The speed tolerance is looser in heat disinfect and flush than the rest of the modes that the concentrate pump are running.
-        cpError   = cpError / cpTargetSpeed;
+        // NOTE: the target speed should be fabs to check the negative target speed too. Negative speed is used in cleaning modes
+        cpError   = cpError / fabs( cpTargetSpeed );
         tolerance = CONCENTRATE_PUMP_TX_SPD_OUT_OF_RANGE_TOL_PCT;
 
         if ( ( DG_MODE_HEAT == opMode ) || ( DG_MODE_FLUS == opMode ) )