Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r4fdc3246f14c8b3b04724d39803530f60b6caac8 -r853d846a60d61d1c6f8987d9cdcfc2bc32913840
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 4fdc3246f14c8b3b04724d39803530f60b6caac8)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 853d846a60d61d1c6f8987d9cdcfc2bc32913840)
@@ -20,6 +20,7 @@
 #include "etpwm.h"
 
 #include "AlarmMgmt.h"
+#include "DGDefs.h"
 #include "Heaters.h"
 #include "ROPump.h"
 #include "PIControllers.h"
@@ -284,6 +285,47 @@
 
 /*********************************************************************//**
  * @brief
+ * The handleTrimmerHeaterCmd handles a start trimmer heater command from the HD.
+ * It resets the trimmer heater's state and sets the duty cycle of the trimmer heater.
+ * @details Inputs: none
+ * @details Outputs: process command and send back response
+ * @param heaterCmdPtr pointer to heater command data record
+ * @return status
+ *************************************************************************/
+void handleTrimmerHeaterCmd( TRIMMER_HEATER_CMD_T *heaterCmdPtr )
+{
+    DG_CMD_RESPONSE_T cmdResponse;
+
+    cmdResponse.commandID = DG_CMD_START_TRIMMER_HEATER;
+    cmdResponse.rejected = TRUE;
+    cmdResponse.rejectCode = DG_CMD_REQUEST_REJECT_REASON_NONE;
+
+    if ( TRUE == heaterCmdPtr->startHeater )
+    {
+        if ( ( MINIMUM_TARGET_TEMPERATURE <= heaterCmdPtr->targetTemp ) && ( heaterCmdPtr->targetTemp <= MAXIMUM_TARGET_TEMPERATURE ) )
+        {
+            cmdResponse.rejected = FALSE;
+    #ifndef DISABLE_HEATERS_AND_TEMPS
+            trimmerHeaterTargetTemperature = heaterCmdPtr->targetTemp;
+            hasStartTrimmerHeaterRequested = TRUE;
+    #endif
+        }
+        else
+        {
+            cmdResponse.rejectCode = DG_CMD_REQUEST_REJECT_REASON_INVALID_PARAMETER;
+        }
+    }
+    else
+    {
+        cmdResponse.rejected = FALSE;
+        stopTrimmerHeater();
+    }
+
+    sendCommandResponseMsg( &cmdResponse );
+}
+
+/*********************************************************************//**
+ * @brief
  * The execHeatersMonitor function turns off the heaters when RO pump is not on.
  * @details Inputs: none
  * @details Outputs: Turns off the heaters when RO pump is not on