diff --git a/actions/diagnostic-test b/actions/diagnostic-test
deleted file mode 100755
index 44a3ee641..000000000
--- a/actions/diagnostic-test
+++ /dev/null
@@ -1,19 +0,0 @@
-#!/bin/sh
-#
-# This file is part of Plinth.
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as
-# published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
-#
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-
-/usr/lib/freedombox/testsuite/check
diff --git a/plinth/modules/diagnostics/diagnostics.py b/plinth/modules/diagnostics/diagnostics.py
index ab9f8b303..0f039cc1f 100644
--- a/plinth/modules/diagnostics/diagnostics.py
+++ b/plinth/modules/diagnostics/diagnostics.py
@@ -19,15 +19,24 @@
 Plinth module for running diagnostics
 """
 
+import collections
 from django.http import Http404
 from django.template.response import TemplateResponse
+from django.views.decorators.http import require_POST
 from gettext import gettext as _
 import importlib
+import logging
+import threading
 
-from plinth import actions
 from plinth import cfg
 from plinth import module_loader
-from plinth.errors import ActionError
+
+
+logger = logging.Logger(__name__)
+
+current_results = {}
+
+_running_task = None
 
 
 def init():
@@ -39,26 +48,16 @@ def init():
 
 def index(request):
     """Serve the index page"""
+    if request.method == 'POST' and not _running_task:
+        _start_task()
+
     return TemplateResponse(request, 'diagnostics.html',
-                            {'title': _('System Diagnostics')})
+                            {'title': _('System Diagnostics'),
+                             'is_running': _running_task is not None,
+                             'results': current_results})
 
 
-def test(request):
-    """Run diagnostics and the output page"""
-    output = ''
-    error = ''
-    try:
-        output = actions.superuser_run("diagnostic-test")
-    except ActionError as exception:
-        output, error = exception.args[1:]
-    except Exception as exception:
-        error = str(exception)
-
-    return TemplateResponse(request, 'diagnostics_test.html',
-                            {'title': _('Diagnostic Test'),
-                             'diagnostics_output': output,
-                             'diagnostics_error': error})
-
+@require_POST
 def module(request, module_name):
     """Return diagnostics for a particular module."""
     found = False
@@ -79,3 +78,49 @@ def module(request, module_name):
                             {'title': _('Diagnostic Test'),
                              'module_name': module_name,
                              'results': results})
+
+
+def _start_task():
+    """Start the run task in a separate thread."""
+    if _running_task:
+        raise Exception('Task already running')
+
+    global _running_task
+    _running_task = threading.Thread(target=_run_on_all_modules_wrapper)
+    _running_task.start()
+
+
+def _run_on_all_modules_wrapper():
+    """Wrapper over actual task to catch exceptions."""
+    try:
+        run_on_all_modules()
+    except Exception as exception:
+        logger.exception('Error running diagnostics - %s', exception)
+        current_results['error'] = str(exception)
+
+    global _running_task
+    _running_task = None
+
+
+def run_on_all_modules():
+    """Run diagnostics on all modules and store the result."""
+    global current_results
+    current_results = {'modules': [],
+                       'results': collections.OrderedDict(),
+                       'progress_percentage': 0}
+
+    modules = []
+    for module_import_path in module_loader.loaded_modules:
+        loaded_module = importlib.import_module(module_import_path)
+        if not hasattr(loaded_module, 'diagnose'):
+            continue
+
+        module_name = module_import_path.split('.')[-1]
+        modules.append((module_name, loaded_module))
+        current_results['results'][module_name] = None
+
+    current_results['modules'] = modules
+    for current_index, (module_name, loaded_module) in enumerate(modules):
+        current_results['results'][module_name] = loaded_module.diagnose()
+        current_results['progress_percentage'] = \
+            int((current_index + 1) * 100 / len(modules))
diff --git a/plinth/modules/diagnostics/templates/diagnostics.html b/plinth/modules/diagnostics/templates/diagnostics.html
index 9a2fbbd17..afb63254c 100644
--- a/plinth/modules/diagnostics/templates/diagnostics.html
+++ b/plinth/modules/diagnostics/templates/diagnostics.html
@@ -18,16 +18,61 @@
 #
 {% endcomment %}
 
+
+{% block page_head %}
+
+  {% if is_running %}
+    <meta http-equiv="refresh" content="3" />
+  {% endif %}
+
+{% endblock %}
+
+
 {% block content %}
 
 <h2>{{ title }}</h2>
 
 <p>The system diagnostic test will run a number of checks on your
-system to confirm that network services are running and configured
-properly. It may take a minute to complete.</p>
+system to confirm that applications and services are working as expected.</p>
 
-<p><a class="btn btn-primary btn-lg" href="{% url 'diagnostics:test' %}">
-  Run diagnostic test &raquo;
-</a></p>
+{% if not is_running %}
+  <form class="form form-diagnostics-button" method="post"
+        action="{% url 'diagnostics:index' %}">
+    {% csrf_token %}
+
+    <input type="submit" class="btn btn-primary" value="Run Diagnostics"/>
+  </form>
+{% else %}
+  <p>Diagnotics test is currently running</p>
+  <div class="progress">
+    <div class="progress-bar progress-bar-striped active"
+         role="progressbar" aria-valuemin="0" aria-valuemax="100"
+         aria-valuenow="{{ results.progress_percentage }}"
+         style="width: {{ results.progress_percentage }}%">
+      {{ results.progress_percentage }}%
+    </div>
+  </div>
+
+{% endif %}
+
+{% if results %}
+  <h3>Results</h3>
+  {% if results.error %}
+    <div class="alert alert-danger alert-dismissable">
+      <a class="close" data-dismiss="alert">&times;</a>
+      {{ results.error }}
+    </div>
+  {% else %}
+    {% for module, module_results in results.results.items %}
+      <h4>Module: {{ module }}</h4>
+
+      {% if module_results %}
+        {% include "diagnostics_results.html" with results=module_results %}
+      {% else %}
+        <p><span class="glyphicon glyphicon-hourglass"></span></p>
+      {% endif %}
+    {% endfor %}
+  {% endif %}
+{% endif %}
 
 {% endblock %}
diff --git a/plinth/modules/diagnostics/templates/diagnostics_test.html b/plinth/modules/diagnostics/templates/diagnostics_test.html
deleted file mode 100644
index d5a345e10..000000000
--- a/plinth/modules/diagnostics/templates/diagnostics_test.html
+++ /dev/null
@@ -1,35 +0,0 @@
-{% extends 'base.html' %}
-{% comment %}
-#
-# This file is part of Plinth.
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU Affero General Public License as
-# published by the Free Software Foundation, either version 3 of the
-# License, or (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU Affero General Public License for more details.
-#
-# You should have received a copy of the GNU Affero General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-#
-{% endcomment %}
-
-{% block content %}
-
-<h2>{{title}}</h2>
-
-{% if diagnostics_error %}
-  <p>The diagnostic test encountered an error:<p>
-  <pre>{{ diagnostics_error }}</pre>
-{% endif %}
-
-{% if diagnostics_output %}
-  <p>Output of diagnostic test:</p>
-  <pre>{{ diagnostics_output }}</pre>
-{% endif %}
-
-{% endblock %}