diff --git a/homeassistant/components/api.py b/homeassistant/components/api.py
index 6a66a2a110e..6d2f9e52a7a 100644
--- a/homeassistant/components/api.py
+++ b/homeassistant/components/api.py
@@ -126,7 +126,9 @@ def _handle_get_api_stream(handler, path_match, data):
                 wfile.write(msg.encode("UTF-8"))
                 wfile.flush()
                 handler.server.sessions.extend_validation(session_id)
-            except IOError:
+            except (IOError, ValueError):
+                # IOError: socket errors
+                # ValueError: raised when 'I/O operation on closed file'
                 block.set()
 
     def forward_events(event):
diff --git a/homeassistant/components/media_player/mpd.py b/homeassistant/components/media_player/mpd.py
index 8134ce5e743..b6c89cbfc3f 100644
--- a/homeassistant/components/media_player/mpd.py
+++ b/homeassistant/components/media_player/mpd.py
@@ -21,14 +21,14 @@ from homeassistant.const import (
 from homeassistant.components.media_player import (
     MediaPlayerDevice,
     SUPPORT_PAUSE, SUPPORT_VOLUME_SET, SUPPORT_TURN_OFF,
-    SUPPORT_PREVIOUS_TRACK, SUPPORT_NEXT_TRACK,
+    SUPPORT_TURN_ON, SUPPORT_PREVIOUS_TRACK, SUPPORT_NEXT_TRACK,
     MEDIA_TYPE_MUSIC)
 
 _LOGGER = logging.getLogger(__name__)
 REQUIREMENTS = ['python-mpd2==0.5.4']
 
 SUPPORT_MPD = SUPPORT_PAUSE | SUPPORT_VOLUME_SET | SUPPORT_TURN_OFF | \
-    SUPPORT_PREVIOUS_TRACK | SUPPORT_NEXT_TRACK
+    SUPPORT_TURN_ON | SUPPORT_PREVIOUS_TRACK | SUPPORT_NEXT_TRACK
 
 
 # pylint: disable=unused-argument
@@ -163,9 +163,13 @@ class MpdDevice(MediaPlayerDevice):
         return SUPPORT_MPD
 
     def turn_off(self):
-        """ Service to exit the running MPD. """
+        """ Service to send the MPD the command to stop playing. """
         self.client.stop()
 
+    def turn_on(self):
+        """ Service to send the MPD the command to start playing. """
+        self.client.play()
+
     def set_volume_level(self, volume):
         """ Sets volume """
         self.client.setvol(int(volume * 100))
diff --git a/homeassistant/exceptions.py b/homeassistant/exceptions.py
index bd32d356670..510bc9b4e54 100644
--- a/homeassistant/exceptions.py
+++ b/homeassistant/exceptions.py
@@ -14,3 +14,10 @@ class InvalidEntityFormatError(HomeAssistantError):
 class NoEntitySpecifiedError(HomeAssistantError):
     """ When no entity is specified. """
     pass
+
+
+class TemplateError(HomeAssistantError):
+    """ Error during template rendering. """
+    def __init__(self, exception):
+        super().__init__('{}: {}'.format(exception.__class__.__name__,
+                                         exception))
diff --git a/homeassistant/util/template.py b/homeassistant/util/template.py
index 107532db776..ad0fabdab53 100644
--- a/homeassistant/util/template.py
+++ b/homeassistant/util/template.py
@@ -6,10 +6,17 @@ Template utility methods for rendering strings with HA data.
 """
 # pylint: disable=too-few-public-methods
 import json
+import logging
+import jinja2
 from jinja2.sandbox import ImmutableSandboxedEnvironment
+from homeassistant.exceptions import TemplateError
+
+_LOGGER = logging.getLogger(__name__)
+_SENTINEL = object()
 
 
-def render_with_possible_json_value(hass, template, value):
+def render_with_possible_json_value(hass, template, value,
+                                    error_value=_SENTINEL):
     """ Renders template with value exposed.
         If valid JSON will expose value_json too. """
     variables = {
@@ -20,7 +27,11 @@ def render_with_possible_json_value(hass, template, value):
     except ValueError:
         pass
 
-    return render(hass, template, variables)
+    try:
+        return render(hass, template, variables)
+    except TemplateError:
+        _LOGGER.exception('Error parsing value')
+        return value if error_value is _SENTINEL else error_value
 
 
 def render(hass, template, variables=None, **kwargs):
@@ -28,9 +39,12 @@ def render(hass, template, variables=None, **kwargs):
     if variables is not None:
         kwargs.update(variables)
 
-    return ENV.from_string(template, {
-        'states': AllStates(hass)
-    }).render(kwargs)
+    try:
+        return ENV.from_string(template, {
+            'states': AllStates(hass)
+        }).render(kwargs)
+    except jinja2.TemplateError as err:
+        raise TemplateError(err)
 
 
 class AllStates(object):
@@ -66,8 +80,8 @@ class DomainStates(object):
 def forgiving_round(value, precision=0):
     """ Rounding method that accepts strings. """
     try:
-        return int(float(value)) if precision == 0 else round(float(value),
-                                                              precision)
+        value = round(float(value), precision)
+        return int(value) if precision == 0 else value
     except ValueError:
         # If value can't be converted to float
         return value
diff --git a/tests/util/test_template.py b/tests/util/test_template.py
index 5c1dfff1f85..ba354f3e7be 100644
--- a/tests/util/test_template.py
+++ b/tests/util/test_template.py
@@ -7,7 +7,7 @@ Tests Home Assistant util methods.
 # pylint: disable=too-many-public-methods
 import unittest
 import homeassistant.core as ha
-
+from homeassistant.exceptions import TemplateError
 from homeassistant.util import template
 
 
@@ -57,10 +57,10 @@ class TestUtilTemplate(unittest.TestCase):
                 '{{ states.sensor.temperature.state | round(1) }}'))
 
     def test_rounding_value2(self):
-        self.hass.states.set('sensor.temperature', 12.72)
+        self.hass.states.set('sensor.temperature', 12.78)
 
         self.assertEqual(
-            '127',
+            '128',
             template.render(
                 self.hass,
                 '{{ states.sensor.temperature.state | multiply(10) | round }}'))
@@ -84,3 +84,19 @@ class TestUtilTemplate(unittest.TestCase):
             '',
             template.render_with_possible_json_value(
                 self.hass, '{{ value_json }}', '{ I AM NOT JSON }'))
+
+    def test_render_with_possible_json_value_with_template_error(self):
+        self.assertEqual(
+            'hello',
+            template.render_with_possible_json_value(
+                self.hass, '{{ value_json', 'hello'))
+
+    def test_render_with_possible_json_value_with_template_error_error_value(self):
+        self.assertEqual(
+            '-',
+            template.render_with_possible_json_value(
+                self.hass, '{{ value_json', 'hello', '-'))
+
+    def test_raise_exception_on_error(self):
+        with self.assertRaises(TemplateError):
+            template.render(self.hass, '{{ invalid_syntax')