diff --git a/Marlin/src/pins/linux/pins_RAMPS_LINUX.h b/Marlin/src/pins/linux/pins_RAMPS_LINUX.h
index ab1446f07c..373002bb81 100644
--- a/Marlin/src/pins/linux/pins_RAMPS_LINUX.h
+++ b/Marlin/src/pins/linux/pins_RAMPS_LINUX.h
@@ -192,7 +192,7 @@
 #else                                             // Non-specific are "EFB" (i.e., "EFBF" or "EFBE")
   #define FAN_PIN                   RAMPS_D9_PIN
   #define HEATER_BED_PIN            RAMPS_D8_PIN
-  #if HOTENDS == 1
+  #if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
     #define FAN1_PIN                MOSFET_D_PIN
   #else
     #define HEATER_1_PIN            MOSFET_D_PIN
diff --git a/Marlin/src/pins/lpc1768/pins_BTT_SKR_common.h b/Marlin/src/pins/lpc1768/pins_BTT_SKR_common.h
index 066c65be3a..d4e6f3f149 100644
--- a/Marlin/src/pins/lpc1768/pins_BTT_SKR_common.h
+++ b/Marlin/src/pins/lpc1768/pins_BTT_SKR_common.h
@@ -65,7 +65,7 @@
   #define TEMP_BED_PIN                  P0_23_A0  // A0 (T0) - (67) - TEMP_BED_PIN
 #endif
 
-#if HOTENDS == 1
+#if HOTENDS == 1 && TEMP_SENSOR_REDUNDANT_SOURCE != 1
   #if TEMP_SENSOR_PROBE
     #define TEMP_PROBE_PIN            TEMP_1_PIN
   #elif TEMP_SENSOR_CHAMBER
@@ -79,7 +79,7 @@
 #ifndef HEATER_0_PIN
   #define HEATER_0_PIN                     P2_07
 #endif
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #ifndef FAN1_PIN
     #define FAN1_PIN                       P2_04
   #endif
diff --git a/Marlin/src/pins/lpc1768/pins_MKS_SGEN_L.h b/Marlin/src/pins/lpc1768/pins_MKS_SGEN_L.h
index f998ecde4e..68e1389841 100644
--- a/Marlin/src/pins/lpc1768/pins_MKS_SGEN_L.h
+++ b/Marlin/src/pins/lpc1768/pins_MKS_SGEN_L.h
@@ -202,7 +202,7 @@
 //
 #define HEATER_BED_PIN                     P2_05
 #define HEATER_0_PIN                       P2_07
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #ifndef FAN1_PIN
     #define FAN1_PIN                       P2_06
   #endif
diff --git a/Marlin/src/pins/lpc1768/pins_RAMPS_RE_ARM.h b/Marlin/src/pins/lpc1768/pins_RAMPS_RE_ARM.h
index 83fcf36e4e..49d4ebb02c 100644
--- a/Marlin/src/pins/lpc1768/pins_RAMPS_RE_ARM.h
+++ b/Marlin/src/pins/lpc1768/pins_RAMPS_RE_ARM.h
@@ -217,7 +217,7 @@
   #define FAN1_PIN                  RAMPS_D8_PIN
 #elif DISABLED(IS_RAMPS_SF)                       // Not Spindle, Fan (i.e., "EFBF" or "EFBE")
   #define HEATER_BED_PIN            RAMPS_D8_PIN
-  #if HOTENDS == 1
+  #if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
     #define FAN1_PIN                MOSFET_D_PIN
   #else
     #define HEATER_1_PIN            MOSFET_D_PIN
diff --git a/Marlin/src/pins/ramps/pins_RAMPS.h b/Marlin/src/pins/ramps/pins_RAMPS.h
index 71e4c13fd6..366554e82d 100644
--- a/Marlin/src/pins/ramps/pins_RAMPS.h
+++ b/Marlin/src/pins/ramps/pins_RAMPS.h
@@ -219,7 +219,7 @@
   #define FAN1_PIN                  RAMPS_D8_PIN
 #elif DISABLED(IS_RAMPS_SF)                       // Not Spindle, Fan (i.e., "EFBF" or "EFBE")
   #define HEATER_BED_PIN            RAMPS_D8_PIN
-  #if HOTENDS == 1
+  #if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
     #define FAN1_PIN                MOSFET_D_PIN
   #else
     #define HEATER_1_PIN            MOSFET_D_PIN
diff --git a/Marlin/src/pins/stm32f1/pins_MKS_ROBIN_NANO.h b/Marlin/src/pins/stm32f1/pins_MKS_ROBIN_NANO.h
index a07af0e692..fc7c7787fc 100644
--- a/Marlin/src/pins/stm32f1/pins_MKS_ROBIN_NANO.h
+++ b/Marlin/src/pins/stm32f1/pins_MKS_ROBIN_NANO.h
@@ -105,7 +105,7 @@
 #ifndef HEATER_0_PIN
   #define HEATER_0_PIN                      PC3
 #endif
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #ifndef FAN1_PIN
     #define FAN1_PIN                        PB0
   #endif
diff --git a/Marlin/src/pins/stm32f4/pins_BTT_SKR_V2_0_common.h b/Marlin/src/pins/stm32f4/pins_BTT_SKR_V2_0_common.h
index d465bb23c7..a9dfc367bf 100644
--- a/Marlin/src/pins/stm32f4/pins_BTT_SKR_V2_0_common.h
+++ b/Marlin/src/pins/stm32f4/pins_BTT_SKR_V2_0_common.h
@@ -210,7 +210,7 @@
 #define TEMP_0_PIN                          PA2   // TH0
 #define TEMP_1_PIN                          PA3   // TH1
 
-#if HOTENDS == 1
+#if HOTENDS == 1 && DISABLED(HEATERS_PARALLEL)
   #if TEMP_SENSOR_PROBE
     #define TEMP_PROBE_PIN            TEMP_1_PIN
   #elif TEMP_SENSOR_CHAMBER