diff --git a/public/live.js b/public/live.js
index ac25e25a..f165883a 100644
--- a/public/live.js
+++ b/public/live.js
@@ -845,6 +845,7 @@
     }
     nodeMarkers = {};
     nodeData = {};
+    if (heatLayer) { map.removeLayer(heatLayer); heatLayer = null; }
   }
 
   function addNodeMarker(n) {