diff --git a/app/src/actions/Connection.ts b/app/src/actions/Connection.ts
index 66efa44..4d30d5a 100644
--- a/app/src/actions/Connection.ts
+++ b/app/src/actions/Connection.ts
@@ -9,7 +9,7 @@ import {
 } from '../../../events'
 import { AppState } from '../reducers'
 import { Dispatch } from 'redux'
-import { MqttOptions } from '../../../backend/src/DataSource'
+import { MqttOptions, DataSourceState } from '../../../backend/src/DataSource'
 import { showTree } from './Tree'
 import { TopicViewModel } from '../TopicViewModel'
 import { showError } from './Global'
@@ -31,6 +31,27 @@ export const connect = (options: MqttOptions, connectionId: string) => (dispatch
       dispatch(showError(dataSourceState.error))
       dispatch(disconnect())
     }
+    dispatch(updateHealth(dataSourceState))
+  })
+}
+
+const updateHealth = (dataSourceState: DataSourceState) => (dispatch: Dispatch<any>, getState: () => AppState) => {
+  let state
+  if (dataSourceState.connecting) {
+    state = 'connecting'
+  } else if (!dataSourceState.connected) {
+    state = 'offline'
+  } else if (dataSourceState.connected) {
+    state = 'online'
+  } else {
+    state = undefined
+  }
+
+  console.log(state)
+
+  dispatch({
+    type: ActionTypes.CONNECTION_SET_HEALTH,
+    health: state,
   })
 }
 
diff --git a/app/src/components/ConnectionHealthIndicator.tsx b/app/src/components/ConnectionHealthIndicator.tsx
new file mode 100644
index 0000000..2cdda59
--- /dev/null
+++ b/app/src/components/ConnectionHealthIndicator.tsx
@@ -0,0 +1,54 @@
+import * as React from 'react'
+import DeviceHubOutlined from '@material-ui/icons/DeviceHubOutlined'
+import { AppState } from '../reducers'
+import { connect } from 'react-redux'
+import { ConnectionHealth } from '../reducers/Connection'
+import { green, orange, red } from '@material-ui/core/colors'
+import { StyleRulesCallback, withStyles } from '@material-ui/core/styles'
+import { Tooltip } from '@material-ui/core';
+
+const styles: StyleRulesCallback = theme => ({
+  offline: {
+    color: red[700],
+  },
+  online: {
+    color: green[500],
+  },
+  connecting: {
+    color: orange[600],
+  },
+})
+
+interface Props {
+  classes: any
+  connected: boolean
+  health?: ConnectionHealth
+}
+
+class ConnectionHealthIndicator extends React.Component<Props, {}> {
+  constructor(props: any) {
+    super(props)
+  }
+
+  public render() {
+    const { classes, health, connected } = this.props
+    if (!health || !connected) {
+      return null
+    }
+
+    return (
+      <Tooltip title={`Connection health "${health}"`}>
+        <DeviceHubOutlined className={classes[health]} />
+      </Tooltip>
+    )
+  }
+}
+
+const mapStateToProps = (state: AppState) => {
+  return {
+    health: state.connection.health,
+    connected: state.connection.connected || state.connection.connecting,
+  }
+}
+
+export default connect(mapStateToProps)(withStyles(styles)(ConnectionHealthIndicator))
diff --git a/app/src/components/ConnectionSetup/ConnectionSettings.tsx b/app/src/components/ConnectionSetup/ConnectionSettings.tsx
index e9bd715..ba53641 100644
--- a/app/src/components/ConnectionSetup/ConnectionSettings.tsx
+++ b/app/src/components/ConnectionSetup/ConnectionSettings.tsx
@@ -14,7 +14,6 @@ import { StyleRulesCallback, Theme, withStyles } from '@material-ui/core/styles'
 
 import {
   Button,
-  CircularProgress,
   FormControl,
   FormControlLabel,
   Grid,
@@ -26,6 +25,7 @@ import {
   Switch,
   TextField,
 } from '@material-ui/core'
+import ConnectionHealthIndicator from '../ConnectionHealthIndicator'
 
 interface Props {
   connection: ConnectionOptions
@@ -284,7 +284,7 @@ class ConnectionSettings extends React.Component<Props, State> {
     if (this.props.connecting) {
       return (
         <Button variant="contained" color="primary" className={classes.button} onClick={actions.disconnect}>
-          <CircularProgress size={22} style={{ marginRight: '10px' }} color="secondary" /> Abort
+          <ConnectionHealthIndicator />&nbsp;&nbsp;Abort
         </Button>
       )
     }
diff --git a/app/src/components/TitleBar.tsx b/app/src/components/TitleBar.tsx
index 7dd2013..de11e55 100644
--- a/app/src/components/TitleBar.tsx
+++ b/app/src/components/TitleBar.tsx
@@ -17,6 +17,7 @@ import { connect } from 'react-redux'
 import { connectionActions, settingsActions } from '../actions'
 import { fade } from '@material-ui/core/styles/colorManipulator'
 import { StyleRulesCallback, withStyles } from '@material-ui/core/styles'
+import ConnectionHealthIndicator from './ConnectionHealthIndicator';
 
 const styles: StyleRulesCallback = theme => ({
   title: {
@@ -99,6 +100,7 @@ class TitleBar extends React.Component<Props, {}> {
           <Button style={{ margin: 'auto 8px auto auto' }} onClick={actions.connection.disconnect}>
             Disconnect <CloudOff style={{ marginRight: '8px', paddingLeft: '8px' }}/>
           </Button>
+          <ConnectionHealthIndicator />
         </Toolbar>
       </AppBar>
     )
diff --git a/app/src/reducers/Connection.ts b/app/src/reducers/Connection.ts
index b7bcc91..d568616 100644
--- a/app/src/reducers/Connection.ts
+++ b/app/src/reducers/Connection.ts
@@ -4,6 +4,7 @@ import * as q from '../../../backend/src/Model'
 import { MqttOptions } from '../../../backend/src/DataSource'
 import { TopicViewModel } from '../TopicViewModel'
 
+export type ConnectionHealth = 'offline' | 'online' | 'connecting'
 export interface ConnectionState {
   host?: string
   tree?: q.Tree<TopicViewModel>
@@ -12,6 +13,7 @@ export interface ConnectionState {
   error?: string
   connected: boolean
   connecting: boolean
+  health?: ConnectionHealth
 }
 
 export type Action = SetConnecting | SetConnected | SetDisconnected | ShowError
@@ -21,6 +23,7 @@ export enum ActionTypes {
   CONNECTION_SET_CONNECTED = 'CONNECTION_SET_CONNECTED',
   CONNECTION_SET_DISCONNECTED = 'CONNECTION_SET_DISCONNECTED',
   CONNECTION_SET_SHOW_ERROR = 'CONNECTION_SET_SHOW_ERROR',
+  CONNECTION_SET_HEALTH = 'CONNECTION_SET_HEALTH',
 }
 
 export interface SetConnecting {
@@ -38,6 +41,11 @@ export interface SetDisconnected {
   type: ActionTypes.CONNECTION_SET_DISCONNECTED
 }
 
+export interface SetHealth {
+  health: ConnectionHealth
+  type: ActionTypes.CONNECTION_SET_DISCONNECTED
+}
+
 export interface ShowError {
   type: ActionTypes.CONNECTION_SET_SHOW_ERROR
   error?: Error
@@ -46,6 +54,7 @@ export interface ShowError {
 const initialState: ConnectionState = {
   connected: false,
   connecting: false,
+  health: 'disconnected',
 }
 
 export const connectionReducer = createReducer(initialState, {
@@ -53,6 +62,7 @@ export const connectionReducer = createReducer(initialState, {
   CONNECTION_SET_CONNECTED: setConnected,
   CONNECTION_SET_DISCONNECTED: setDisconnected,
   CONNECTION_SET_SHOW_ERROR: showError,
+  CONNECTION_SET_HEALTH: setHealth,
 })
 
 function setConnecting(state: ConnectionState, action: SetConnecting): ConnectionState {
@@ -64,6 +74,13 @@ function setConnecting(state: ConnectionState, action: SetConnecting): Connectio
   }
 }
 
+function setHealth(state: ConnectionState, action: SetHealth): ConnectionState {
+  return {
+    ...state,
+    health: action.health,
+  }
+}
+
 function setConnected(state: ConnectionState, action: SetConnected): ConnectionState {
   return {
     ...state,
diff --git a/backend/src/DataSource/DataSourceState.ts b/backend/src/DataSource/DataSourceState.ts
index 1be3fc0..861304c 100644
--- a/backend/src/DataSource/DataSourceState.ts
+++ b/backend/src/DataSource/DataSourceState.ts
@@ -25,16 +25,17 @@ export class DataSourceStateMachine {
 
   public setError(error: Error) {
     this.state = {
+      ...this.state,
       error: error.message,
-      connected: false,
-      connecting: false,
+      // connected: false,
+      // connecting: false,
     }
     this.onUpdate.dispatch(this.state)
   }
 
   public setConnecting() {
     this.state = {
-      error: undefined,
+      ...this.state,
       connected: false,
       connecting: true,
     }
diff --git a/backend/src/DataSource/MqttSource.ts b/backend/src/DataSource/MqttSource.ts
index 4926480..6d55a44 100644
--- a/backend/src/DataSource/MqttSource.ts
+++ b/backend/src/DataSource/MqttSource.ts
@@ -55,6 +55,10 @@ export class MqttSource implements DataSource<MqttOptions> {
       this.stateMachine.setConnected(false)
     })
 
+    client.on('end', () => {
+      this.stateMachine.setConnected(false)
+    })
+
     client.on('reconnect', () => {
       this.stateMachine.setConnecting()
     })
diff --git a/backend/src/index.ts b/backend/src/index.ts
index fd8dfdd..ac82d6c 100644
--- a/backend/src/index.ts
+++ b/backend/src/index.ts
@@ -61,6 +61,7 @@ export class ConnectionManager {
     if (connection) {
       connection.disconnect()
       delete this.connections[hash]
+      connection.stateMachine.onUpdate.removeAllListeners()
     }
   }