Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -rf14371c9c14b461a50d7b08336e2e5fbed16f360 -r0d0febfa1b9e9e8d72f9db47f21b8c7882d91740
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision f14371c9c14b461a50d7b08336e2e5fbed16f360)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 0d0febfa1b9e9e8d72f9db47f21b8c7882d91740)
@@ -82,6 +82,7 @@
 #define AC_HEATER_PWM_PERIOD                                       10000                                                           ///< PWM period 100 ms( in 10us resoultion), 1/10Hz = 1000000us/10us = 10000.
 #define AC_HEATER_EFFICIENCY                                       0.90F                                                           ///< Approximated AC heater efficiency to be used in energy calcualtions.
 #define DC_HEATER_EFFICIENCY                                       1.0F                                                            ///< DC heater efficiency
+#define D5_HEAT_CONTROL_INTERVAL_START_COUNT                       ( D5_HEAT_CONTROL_INTERVAL_COUNT - 10 )                         ///< AC heater control interval start count to jump feedforward control from open loop.
 
 #define DATA_PUBLISH_COUNTER_START_COUNT                           70                                                              ///< Data publish counter start count.
 
@@ -176,7 +177,7 @@
     controlInterval[ D45_HEAT ]         = D45_HEAT_CONTROL_INTERVAL_COUNT;
 
     // Assign counter close to the target period
-    heatersStatus[ D5_HEAT ].controlIntervalCounter  = 590;
+    heatersStatus[ D5_HEAT ].controlIntervalCounter  = D5_HEAT_CONTROL_INTERVAL_START_COUNT;
     heatersStatus[ D45_HEAT ].controlIntervalCounter = 0;
     startupHeaterControl                             = TRUE;
 
@@ -371,7 +372,7 @@
         heatersStatus[ heater ].heaterOnState               = FALSE;
         control[ heater ].data                              = HEATERS_MIN_DUTY_CYCLE;
         heatersStatus[ heater ].state                       = HEATER_EXEC_STATE_OFF;
-        heatersStatus[ D5_HEAT ].controlIntervalCounter     = 590;
+        heatersStatus[ D5_HEAT ].controlIntervalCounter     = D5_HEAT_CONTROL_INTERVAL_START_COUNT;
         heatersStatus[ D45_HEAT ].controlIntervalCounter    = 0;
         startupHeaterControl                                = TRUE;