diff --git a/game/reconstructed/heat.hpp b/game/reconstructed/heat.hpp
index eb61e45..2e8451a 100644
--- a/game/reconstructed/heat.hpp
+++ b/game/reconstructed/heat.hpp
@@ -554,7 +554,7 @@ inline int
 		void
 			RefrigerationSimulation(Scalar time_slice);	// @4ae4d8 (vtable slot 9)
 		void
-			MoveValve(int message);						// @4afbe0 (best-effort)
+			MoveValve(int message);						// @4ae464 (valve cycle 1->5->50->0; dormant until 0xBD3)
 		virtual void
 			SetValveSetting(int setting)				{ valveState = setting; }
 
diff --git a/game/reconstructed/heatfamily_reslice.cpp b/game/reconstructed/heatfamily_reslice.cpp
index df2516d..59ad9d7 100644
--- a/game/reconstructed/heatfamily_reslice.cpp
+++ b/game/reconstructed/heatfamily_reslice.cpp
@@ -47,6 +47,9 @@
 //
 static const Scalar CoolantCapacityScale = 1.738f;	// _DAT_004af518 (~ master-sink capacity scale)
 
+// FUN_0049f788 -- defined near the foot of this file; forward-declared for MoveValve.
+void BTRecomputeCondenserValves(Entity *owner);
+
 //###########################################################################
 //###########################################################################
 //					Condenser   (COMPLETION of heat.cpp best-effort)
@@ -142,36 +145,37 @@ void
 }
 
 //
-// @4afbe0 -- BEST-EFFORT.  The "MoveValve" handler: cycles a 3-position valve
-// (0->1->2->0), tells the model (virtual slot 18, vtable+0x48) the new
-// setting, and re-points two HUD graphic gauges on the owner.  Mapped to the
-// Condenser by its "MoveValve"/"ValveSetting" strings and the valveState word.
+// @4ae464 -- the REAL "MoveValve" message handler (disassembled; the assert-anchored
+// exporter did not capture it).  Cycles the coolant valve through its FOUR settings
+// 1 -> 5 -> 50 -> 0 -> 1 (NOT the 0/1/2 the earlier draft guessed -- that draft had
+// FUN_004afbe0's body, which is a CONTROLS-mapper display-mode cycler @0x190, a
+// mislabel).  After changing valveState it redistributes coolant flow across all
+// condensers (RecomputeCondenserValves) so every ValveSetting gauge updates.
+//
+// ROUTE/GUARD are DEFERRED to WAVE 8: the binary guards on
+//   owner->messageManager(+0x190)->field_0x274 == 0   (FUN_004ac9c8, the 0xBD3
+// SubsystemMessageManager, unreconstructed) and the message that CALLS this arrives
+// through that same manager.  Reproducing the raw owner+0x190 deref would be a
+// databinding trap in our layout, and there is no route to invoke this yet, so the
+// handler is faithful-but-DORMANT: the valve gauge shows the authentic static 1/N
+// (RecomputeCondenserValves at ctor) until the message manager is reconstructed.
 //
 void
-	Condenser::MoveValve(int message)			// FUN_004afbe0
+	Condenser::MoveValve(int message)			// FUN_004ae464
 {
-	if (message /*param_2->count*/ > 0)
-	{
-		valveState = (valveState + 1) % 3;		// this[100] cycle 0..2
-		SetValveSetting(valveState);			// (**(*this+0x48))(this, valveState)
+	// binary: if (FUN_004ac9c8(this)) return;   -- messmgr guard, deferred (see note)
+	if (message /* *(int*)(param_2+0xc) = msg->count */ <= 0)
+		return;
 
-		// HUD gauge re-point: owner->field_438 / owner->field_5b4 are the two
-		// cockpit graphic gauges this valve drives.  Resolving them is a Mech
-		// game-layer concern (CROSS-FAMILY); the branch bodies below are stubs.
-		(void)this->owner;						// this[0x34]
-		void *gaugeA = 0;
-		void *gaugeB = 0;
-		(void)gaugeA; (void)gaugeB;
-		if (valveState == 0)
-		{
-			// gaugeA: reset + select primary read-out, signal gaugeB.
-			// (offsets +0x1f0/+0x274/+0x220/+0x224/+0x228/+0x22c/+0x2a0)
-		}
-		else /* valveState == 1 || 2 */
-		{
-			// gaugeA: select alternate read-out (+0x230/+0x234).
-		}
+	switch (valveState)							// this[0x74] @0x1D0
+	{
+		case 0:  valveState = 1;  break;		// @4ae499
+		case 1:  valveState = 5;  break;		// @4ae4a5
+		case 5:  valveState = 50; break;		// @4ae4b1 (0x32)
+		case 50: valveState = 0;  break;		// @4ae4bd
+		default: return;						// @4ae497 unknown -> no change / no recompute
 	}
+	BTRecomputeCondenserValves((Entity *)owner);	// FUN_0049f788(this[0xd0]=owner Mech)
 }
 
 //