Index: firmware/App/Controllers/Heaters.c
===================================================================
diff -u -r1aeab08c1baf6445514b81fe51fc60a3e536e782 -r3b5080777e3dac1b5802ee18227f66a0b49deefa
--- firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 1aeab08c1baf6445514b81fe51fc60a3e536e782)
+++ firmware/App/Controllers/Heaters.c	(.../Heaters.c)	(revision 3b5080777e3dac1b5802ee18227f66a0b49deefa)
@@ -68,6 +68,8 @@
 #define DELTA_TEMPERATURE_TIME_COSNTANT_C                          8.6                                                             ///< Delta temperature calculated from time constant.
 #define MAXIMUM_ALLOWED_TARGET_TEMPERATURE_DEVIATION_C             0.25                                                            ///< Maximum allowed temperature deviation from target temperature in C.
 #define PRIMARY_HEATER_DUTY_CYCLE_PER_TEMPERATURE_C                0.03                                                            ///< Primary heaters duty cycle per temperature in C.
+#define RESERVOIR_TEMPERATURE_TIME_CONSTANT_C_PER_MIN              0.512                                                           ///< Reservoir temperature time constant C/min.
+#define ULTRAFILTER_TEMPERATURE_TIME_CONSTANT_C_PER_MIN            0.345                                                           ///< Ultrafilter temperature time constant C/min.
 
 static const F32 WATER_SPECIFIC_HEAT_DIVIDED_BY_MINUTES = 4184 / SEC_PER_MIN;                                                      ///< Water specific heat in J/KgC / 60.
 static const F32 PRIMARY_HEATERS_MAXIMUM_POWER_WATTS    = 475 + 237.5;                                                             ///< Primary heaters maximum power (main primary = 475W and small primary = 237.5W).