diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/HeatmapPresenter.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/HeatmapPresenter.java
index 407c2052d14a1176db10dff8c528c3649704d8a5..3c0717ecab497d0daed4d6db66a591940e100eef 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/HeatmapPresenter.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/HeatmapPresenter.java
@@ -260,11 +260,17 @@ class HeatmapPresenter
                     new AbstractAsyncCallback<FeatureVectorValues>(viewContext)
                         {
                             @Override
-                            protected void process(FeatureVectorValues result)
+                            protected void process(FeatureVectorValues resultOrNull)
                             {
                                 viewContext.log("Update Well Feature Values: "
                                         + wellData.getWellLocation().toString());
-                                model.updateWellFeatureValues(result);
+                                if (resultOrNull != null)
+                                {
+                                    model.updateWellFeatureValues(resultOrNull);
+                                } else
+                                {
+                                    model.resetFeatureValues(wellData);
+                                }
                                 refreshTooltipAction.execute();
                             }
                         };
diff --git a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouterModel.java b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouterModel.java
index a0bc8831b13fb52b1482f8479f310e6980fc7cd7..1ff96f3421d1f953aab987333f5a5a90d5f75e0b 100644
--- a/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouterModel.java
+++ b/screening/source/java/ch/systemsx/cisd/openbis/plugin/screening/client/web/client/application/detailviewers/heatmaps/PlateLayouterModel.java
@@ -186,6 +186,11 @@ class PlateLayouterModel
         }
     }
 
+    public void resetFeatureValues(WellData wellData)
+    {
+        wellData.resetFeatureValues();
+    }
+
     // set all well's features
     public void updateWellFeatureValues(FeatureVectorValues wellFeatureVectorValues)
     {