Index: firmware/App/Modes/ModeFault.c
===================================================================
diff -u -r32b198b922f305a1838fe10e42d5dc83325f0180 -rdff17385da6583e18826af9d1b18c312d52be2f3
--- firmware/App/Modes/ModeFault.c	(.../ModeFault.c)	(revision 32b198b922f305a1838fe10e42d5dc83325f0180)
+++ firmware/App/Modes/ModeFault.c	(.../ModeFault.c)	(revision dff17385da6583e18826af9d1b18c312d52be2f3)
@@ -217,7 +217,8 @@
     setRinsePumpState( RINSE_PUMP_STATE_OFF );
     stopHeater( D5_HEAT );
     stopHeater( D45_HEAT );
-    stopHeater( D108_HEAT );
+    // TODO: Stop D108 substitution fluid heater once D108 driver support is implemented.
+    // stopHeater( D108_HEAT );
 }
 
 /*********************************************************************//**
@@ -276,7 +277,8 @@
     setRinsePumpState( RINSE_PUMP_STATE_OFF );
     stopHeater( D5_HEAT );
     stopHeater( D45_HEAT );
-    stopHeater( D108_HEAT );
+    // TODO: Stop D108 substitution fluid heater once D108 driver support is implemented.
+    // stopHeater( D108_HEAT );
 }
 
 /*********************************************************************//**