diff --git a/red/api/index.js b/red/api/index.js
index 48ae6fcff..a84751573 100644
--- a/red/api/index.js
+++ b/red/api/index.js
@@ -1,5 +1,5 @@
 /**
- * Copyright 2014, 2015 IBM Corp.
+ * Copyright 2014, 2016 IBM Corp.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -40,6 +40,7 @@ var log;
 var adminApp;
 var nodeApp;
 var server;
+var runtime;
 
 var errorHandler = function(err,req,res,next) {
     if (err.message === "request entity too large") {
@@ -51,8 +52,18 @@ var errorHandler = function(err,req,res,next) {
     res.status(400).json({error:"unexpected_error", message:err.toString()});
 };
 
-function init(_server,runtime) {
+var ensureRuntimeStarted = function(req,res,next) {
+    if (!runtime.isStarted()) {
+        log.error("Node-RED runtime not started");
+        res.status(503).send("Not started");
+    } else {
+        next();
+    }
+}
+
+function init(_server,_runtime) {
     server = _server;
+    runtime = _runtime;
     var settings = runtime.settings;
     i18n = runtime.i18n;
     log = runtime.log;
@@ -75,7 +86,7 @@ function init(_server,runtime) {
         if (!settings.disableEditor) {
             ui.init(runtime);
             var editorApp = express();
-            editorApp.get("/",ui.ensureSlash,ui.editor);
+            editorApp.get("/",ensureRuntimeStarted,ui.ensureSlash,ui.editor);
             editorApp.get("/icons/:icon",ui.icon);
             theme.init(runtime);
             if (settings.editorTheme) {
diff --git a/red/runtime/index.js b/red/runtime/index.js
index 723141011..5bf9a2f0e 100644
--- a/red/runtime/index.js
+++ b/red/runtime/index.js
@@ -1,5 +1,5 @@
 /**
- * Copyright 2013, 2015 IBM Corp.
+ * Copyright 2013, 2016 IBM Corp.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,6 +28,8 @@ var os = require("os");
 
 var runtimeMetricInterval = null;
 
+var started = false;
+
 var stubbedExpressApp = {
     get: function() {},
     post: function() {},
@@ -142,6 +144,7 @@ function start() {
                     log.info(log._("runtime.paths.settings",{path:settings.settingsFile}));
                 }
                 redNodes.loadFlows().then(redNodes.startFlows);
+                started = true;
             }).otherwise(function(err) {
                 console.log(err);
             });
@@ -173,6 +176,7 @@ function stop() {
         clearInterval(runtimeMetricInterval);
         runtimeMetricInterval = null;
     }
+    started = false;
     return redNodes.stopFlows();
 }
 
@@ -190,5 +194,8 @@ var runtime = module.exports = {
     events: events,
     nodes: redNodes,
     util: require("./util"),
-    get adminApi() { return adminApi }
+    get adminApi() { return adminApi },
+    isStarted: function() {
+        return started;
+    }
 }
diff --git a/test/red/api/index_spec.js b/test/red/api/index_spec.js
index ef1ae4294..b73444eb1 100644
--- a/test/red/api/index_spec.js
+++ b/test/red/api/index_spec.js
@@ -1,5 +1,5 @@
 /**
- * Copyright 2014 IBM Corp.
+ * Copyright 2014, 2016 IBM Corp.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -87,6 +87,45 @@ describe("api index", function() {
         });
     });
 
+    describe("editor warns if runtime not started", function() {
+        var mockList = [
+            'nodes','flows','library','info','theme','locales','credentials'
+        ]
+        before(function() {
+            mockList.forEach(function(m) {
+                sinon.stub(require("../../../red/api/"+m),"init",function(){});
+            });
+        });
+        after(function() {
+            mockList.forEach(function(m) {
+                require("../../../red/api/"+m).init.restore();
+            })
+        });
+
+        it('serves the editor', function(done) {
+            var errorLog = sinon.spy();
+            api.init({},{
+                log:{audit:function(){},error:errorLog},
+                settings:{httpNodeRoot:true, httpAdminRoot: true,disableEditor:false},
+                events:{on:function(){},removeListener:function(){}},
+                isStarted: function() { return false; } // <-----
+            });
+            app = api.adminApp;
+            request(app)
+                .get("/")
+                .expect(503)
+                .end(function(err,res) {
+                    if (err) {
+                        return done(err);
+                    }
+                    res.text.should.eql("Not started");
+                    errorLog.calledOnce.should.be.true;
+                    done();
+                });
+        });
+
+    });
+
     describe("enables editor", function() {
 
         var mockList = [
@@ -107,7 +146,8 @@ describe("api index", function() {
             api.init({},{
                 log:{audit:function(){}},
                 settings:{httpNodeRoot:true, httpAdminRoot: true,disableEditor:false},
-                events:{on:function(){},removeListener:function(){}}
+                events:{on:function(){},removeListener:function(){}},
+                isStarted: function() { return true; }
             });
             app = api.adminApp;
         });