Sanity check for too many temp sensors

Marlin/SanityCheck.h

@@ -564,8 +564,20 @@
       #elif !PIN_EXISTS(TEMP_3)
         #error "TEMP_3_PIN not defined for this board."
       #endif
-    #endif
+    #elif TEMP_SENSOR_3 != 0
-  #endif
+      #error "TEMP_SENSOR_3 shouldn't be set with only 3 extruders."
+    #endif
+  #elif TEMP_SENSOR_2 != 0
+    #error "TEMP_SENSOR_2 shouldn't be set with only 2 extruders."
+  #elif TEMP_SENSOR_3 != 0
+    #error "TEMP_SENSOR_3 shouldn't be set with only 2 extruders."
+  #endif
+#elif TEMP_SENSOR_1 != 0 && DISABLED(TEMP_SENSOR_1_AS_REDUNDANT)
+  #error "TEMP_SENSOR_1 shouldn't be set with only 1 extruder."
+#elif TEMP_SENSOR_2 != 0
+  #error "TEMP_SENSOR_2 shouldn't be set with only 1 extruder."
+#elif TEMP_SENSOR_3 != 0
+  #error "TEMP_SENSOR_3 shouldn't be set with only 1 extruder."
 #endif
 
 #if ENABLED(TEMP_SENSOR_1_AS_REDUNDANT) && TEMP_SENSOR_1 == 0