Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -ra5e4e578efe1af6c82530e73d58b09b2b7ad625c -r7c077d84b9db9f8b14d4ab49d4b02a7f41e8f923
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision a5e4e578efe1af6c82530e73d58b09b2b7ad625c)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 7c077d84b9db9f8b14d4ab49d4b02a7f41e8f923)
@@ -671,26 +671,29 @@
     // Get the primary heater's efficiency and the last fill temperature from the ModeFill
     F32 heaterEfficiency = heatersStatus[ DG_PRIMARY_HEATER ].heaterEfficiency;
 
-    /*if ( TRUE == checkEfficiency )
+    if ( TRUE == checkEfficiency )  // TODO ignore the efficiency for now until it is fixed
     {
-        F32 lastFillTemperature      = getLastFillTemperature();
-        F32 trimmerTargetTemperature = heatersStatus[ DG_TRIMMER_HEATER ].targetTemp;
+        /*F32 lastFillTemperature      = getLastFillTemperature();
+        F32 primaryTargetTemperature = heatersStatus[ DG_PRIMARY_HEATER ].targetTemp;
 
         // If the last fill temperature > target temperature, it means the primary heater overshot the duty cycle
         // so with its efficiency is toned down for the next fill cycle
         // If the heater under-shoots the duty cycle, the efficiency increases the duty cycle for the next fill cycle
-        if ( lastFillTemperature - trimmerTargetTemperature > MAXIMUM_ALLOWED_TARGET_TEMPERATURE_DEVIATION_C )
+        if ( lastFillTemperature - primaryTargetTemperature > MAXIMUM_ALLOWED_TARGET_TEMPERATURE_DEVIATION_C )
         {
-            heaterEfficiency -= ( lastFillTemperature - trimmerTargetTemperature ) * PRIMARY_HEATER_DUTY_CYCLE_PER_TEMPERATURE_C;
+            heaterEfficiency -= ( lastFillTemperature - primaryTargetTemperature ) * PRIMARY_HEATER_DUTY_CYCLE_PER_TEMPERATURE_C;
         }
-        else if ( lastFillTemperature - trimmerTargetTemperature <= MAXIMUM_ALLOWED_TARGET_TEMPERATURE_DEVIATION_C )
+        else if ( lastFillTemperature - primaryTargetTemperature <= MAXIMUM_ALLOWED_TARGET_TEMPERATURE_DEVIATION_C )
         {
-            heaterEfficiency += ( lastFillTemperature - trimmerTargetTemperature ) * PRIMARY_HEATER_DUTY_CYCLE_PER_TEMPERATURE_C;
+            heaterEfficiency += ( primaryTargetTemperature - lastFillTemperature ) * PRIMARY_HEATER_DUTY_CYCLE_PER_TEMPERATURE_C;
         }
 
+        heaterEfficiency = heaterEfficiency <= 0.0 ? 0.0 : heaterEfficiency;
+        //heaterEfficiency = heaterEfficiency >= 1.0 ? 1.0 : heaterEfficiency;
+
         // Update the heaters efficiency
-        heatersStatus[ DG_PRIMARY_HEATER ].heaterEfficiency = heaterEfficiency;
-    }*/
+        heatersStatus[ DG_PRIMARY_HEATER ].heaterEfficiency = heaterEfficiency; */
+    }
 
     // Duty cycle = ( 69.73 * flow rate * deltaT / primary heater maximum power ) ^ 1/2
     // Multiply the duty cycle to the heater efficiency