diff --git a/examples/all-clusters-app/all-clusters-common/include/WhmDelegate.h b/examples/all-clusters-app/all-clusters-common/include/WhmDelegate.h
index ecabfe22792f25..ad73239e77990d 100644
--- a/examples/all-clusters-app/all-clusters-common/include/WhmDelegate.h
+++ b/examples/all-clusters-app/all-clusters-common/include/WhmDelegate.h
@@ -167,7 +167,7 @@ class WaterHeaterManagementDelegate : public WaterHeaterManagement::Delegate
      * @param percentageReplaced  The % of water being replaced with water with a temperature of replacedWaterTemperature.
      * @param replacedWaterTemperature  The temperature of the percentageReplaced water.
      */
-    void DrawOffHotWater(uint8_t percentageReplaced, uint16_t replacedWaterTemperature);
+    void DrawOffHotWater(chip::Percent percentageReplaced, uint16_t replacedWaterTemperature);
 
 private:
     /**
diff --git a/examples/all-clusters-app/all-clusters-common/src/WhmDelegateImpl.cpp b/examples/all-clusters-app/all-clusters-common/src/WhmDelegateImpl.cpp
index fd19a3c59d740b..0568e5c9c7d002 100644
--- a/examples/all-clusters-app/all-clusters-common/src/WhmDelegateImpl.cpp
+++ b/examples/all-clusters-app/all-clusters-common/src/WhmDelegateImpl.cpp
@@ -294,7 +294,7 @@ void WaterHeaterManagementDelegate::SetTargetWaterTemperature(uint16_t targetWat
     CheckIfHeatNeedsToBeTurnedOnOrOff();
 }
 
-void WaterHeaterManagementDelegate::DrawOffHotWater(uint8_t percentageReplaced, uint16_t replacedWaterTemperature)
+void WaterHeaterManagementDelegate::DrawOffHotWater(Percent percentageReplaced, uint16_t replacedWaterTemperature)
 {
     // Only supported in the kTankPercent is supported.
     // Replaces percentageReplaced% of the water in the tank with water of a temperature replacedWaterTemperature
@@ -303,7 +303,7 @@ void WaterHeaterManagementDelegate::DrawOffHotWater(uint8_t percentageReplaced,
         // See if all of the water has now been replaced with replacedWaterTemperature
         if (mTankPercentage >= percentageReplaced)
         {
-            mTankPercentage -= percentageReplaced;
+            mTankPercentage = static_cast<Percent>(mTankPercentage - percentageReplaced);
         }
         else
         {