Index: firmware/App/Controllers/DialInFlow.c
===================================================================
diff -u -r0b920c7149620ef5d32f118efc9414c6e7319dfa -r42db67ae5e0568843ec1b8c4733d1279ea2d6169
--- firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision 0b920c7149620ef5d32f118efc9414c6e7319dfa)
+++ firmware/App/Controllers/DialInFlow.c	(.../DialInFlow.c)	(revision 42db67ae5e0568843ec1b8c4733d1279ea2d6169)
@@ -290,7 +290,7 @@
                 dialInPumpDirection = dir;
                 dialInPumpControlMode = mode;
                 // Set PWM duty cycle target to an estimated initial target to ramp to based on target flow rate - then we will control to flow when ramp completed
-                dialInPumpPWMDutyCyclePct = DIP_PWM_FROM_ML_PER_MIN((F32)flowRate);   // ~ 8% per 100 mL/min with a 10% zero offset added in (e.g. 100 mL/min = 8+10 = 18%)
+                dialInPumpPWMDutyCyclePct = ( 0 == flowRate ? DIP_PWM_ZERO_OFFSET : DIP_PWM_FROM_ML_PER_MIN( (F32)flowRate ) );
 
                 switch ( dialInPumpState )
                 {
@@ -299,13 +299,15 @@
                         {
                             dialInPumpState = DIAL_IN_PUMP_RAMPING_DOWN_STATE;
                         }
-                        break;
+                        break;
+
                     case DIAL_IN_PUMP_RAMPING_DOWN_STATE:  // See if we need to reverse direction of ramp
                         if ( dialInPumpPWMDutyCyclePct > dialInPumpPWMDutyCyclePctSet )
                         {
                             dialInPumpState = DIAL_IN_PUMP_RAMPING_UP_STATE;
                         }
-                        break;
+                        break;
+
                     case DIAL_IN_PUMP_CONTROL_TO_TARGET_STATE:  // Start ramp to new target in appropriate direction
                         if ( dialInPumpPWMDutyCyclePctSet > dialInPumpPWMDutyCyclePct )
                         {
@@ -315,7 +317,8 @@
                         {
                             dialInPumpState = DIAL_IN_PUMP_RAMPING_UP_STATE;
                         }
-                        break;
+                        break;
+
                     default:
                         // Ok - not all states need to be handled here
                         break;
@@ -1385,7 +1388,14 @@
         }
         if ( ctrlMode < NUM_OF_PUMP_CONTROL_MODES )
         {
-            result = setDialInPumpTargetFlowRate( abs(value), dir, (PUMP_CONTROL_MODE_T)ctrlMode );
+            if ( 0 == value )
+            {
+                signalDialInPumpHardStop();
+            }
+            else
+            {
+                result = setDialInPumpTargetFlowRate( abs(value), dir, (PUMP_CONTROL_MODE_T)ctrlMode );
+            }
         }
     }
 
Index: firmware/App/Controllers/DialOutFlow.c
===================================================================
diff -u -r450fd51053df274149ec091955baa33e23e1c7a7 -r42db67ae5e0568843ec1b8c4733d1279ea2d6169
--- firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision 450fd51053df274149ec091955baa33e23e1c7a7)
+++ firmware/App/Controllers/DialOutFlow.c	(.../DialOutFlow.c)	(revision 42db67ae5e0568843ec1b8c4733d1279ea2d6169)
@@ -261,7 +261,7 @@
     // Direction change while pump is running is not allowed
     if ( ( FALSE == isDialOutPumpOn ) || ( 0 == flowRate ) || ( dir == dialOutPumpDirectionSet ) )
     {
-        F32 pwmDC = DOP_PWM_FROM_ML_PER_MIN( (F32)flowRate );
+        F32 pwmDC = ( 0 == flowRate ? DOP_PWM_ZERO_OFFSET : DOP_PWM_FROM_ML_PER_MIN( (F32)flowRate ) );
 
         // Don't interrupt pump control unless rate or mode is changing
         if ( ( fabs( pwmDC - dialOutPumpPWMDutyCyclePct ) > NEARLY_ZERO ) || ( mode != dialOutPumpControlMode ) )
@@ -1334,7 +1334,14 @@
         }
         if ( ctrlMode < NUM_OF_PUMP_CONTROL_MODES )
         {
-            result = setDialOutPumpTargetRate( abs(value), dir, (PUMP_CONTROL_MODE_T)ctrlMode );
+            if ( 0 == value )
+            {
+                signalDialOutPumpHardStop();
+            }
+            else
+            {
+                result = setDialOutPumpTargetRate( abs(value), dir, (PUMP_CONTROL_MODE_T)ctrlMode );
+            }
         }
     }