diff --git a/homeassistant/components/binary_sensor/threshold.py b/homeassistant/components/binary_sensor/threshold.py
new file mode 100644
index 00000000000..4dc11a3c5c7
--- /dev/null
+++ b/homeassistant/components/binary_sensor/threshold.py
@@ -0,0 +1,128 @@
+"""
+Support for monitoring if a sensor value is below/above a threshold.
+
+For more details about this platform, please refer to the documentation at
+https://home-assistant.io/components/sensor.threshold/
+"""
+import asyncio
+import logging
+
+import voluptuous as vol
+
+import homeassistant.helpers.config_validation as cv
+from homeassistant.components.binary_sensor import (
+    BinarySensorDevice, PLATFORM_SCHEMA, SENSOR_CLASSES_SCHEMA)
+from homeassistant.const import (
+    CONF_NAME, CONF_ENTITY_ID, CONF_TYPE, STATE_UNKNOWN, CONF_SENSOR_CLASS,
+    ATTR_ENTITY_ID)
+from homeassistant.core import callback
+from homeassistant.helpers.event import async_track_state_change
+
+_LOGGER = logging.getLogger(__name__)
+
+ATTR_SENSOR_VALUE = 'sensor_value'
+ATTR_THRESHOLD = 'threshold'
+ATTR_TYPE = 'type'
+
+CONF_LOWER = 'lower'
+CONF_THRESHOLD = 'threshold'
+CONF_UPPER = 'upper'
+
+DEFAULT_NAME = 'Threshold'
+
+SENSOR_TYPES = [CONF_LOWER, CONF_UPPER]
+
+PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend({
+    vol.Required(CONF_ENTITY_ID): cv.entity_id,
+    vol.Required(CONF_THRESHOLD): vol.Coerce(float),
+    vol.Required(CONF_TYPE): vol.In(SENSOR_TYPES),
+    vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
+    vol.Optional(CONF_SENSOR_CLASS, default=None): SENSOR_CLASSES_SCHEMA,
+})
+
+
+@asyncio.coroutine
+def async_setup_platform(hass, config, async_add_devices, discovery_info=None):
+    """Set up the Threshold sensor."""
+    entity_id = config.get(CONF_ENTITY_ID)
+    name = config.get(CONF_NAME)
+    threshold = config.get(CONF_THRESHOLD)
+    limit_type = config.get(CONF_TYPE)
+    sensor_class = config.get(CONF_SENSOR_CLASS)
+
+    yield from async_add_devices(
+        [ThresholdSensor(hass, entity_id, name, threshold, limit_type,
+                         sensor_class)], True)
+    return True
+
+
+class ThresholdSensor(BinarySensorDevice):
+    """Representation of a Threshold sensor."""
+
+    def __init__(self, hass, entity_id, name, threshold, limit_type,
+                 sensor_class):
+        """Initialize the Threshold sensor."""
+        self._hass = hass
+        self._entity_id = entity_id
+        self.is_upper = limit_type == 'upper'
+        self._name = name
+        self._threshold = threshold
+        self._sensor_class = sensor_class
+        self._deviation = False
+        self.sensor_value = 0
+
+        @callback
+        # pylint: disable=invalid-name
+        def async_threshold_sensor_state_listener(
+                entity, old_state, new_state):
+            """Called when the sensor changes state."""
+            if new_state.state == STATE_UNKNOWN:
+                return
+
+            try:
+                self.sensor_value = float(new_state.state)
+            except ValueError:
+                _LOGGER.error("State is not numerical")
+
+            hass.async_add_job(self.async_update_ha_state, True)
+
+        async_track_state_change(
+            hass, entity_id, async_threshold_sensor_state_listener)
+
+    @property
+    def name(self):
+        """Return the name of the sensor."""
+        return self._name
+
+    @property
+    def is_on(self):
+        """Return true if sensor is on."""
+        return self._deviation
+
+    @property
+    def should_poll(self):
+        """No polling needed."""
+        return False
+
+    @property
+    def sensor_class(self):
+        """Return the sensor class of the sensor."""
+        return self._sensor_class
+
+    @property
+    def state_attributes(self):
+        """Return the state attributes of the sensor."""
+        return {
+            ATTR_ENTITY_ID: self._entity_id,
+            ATTR_SENSOR_VALUE: self.sensor_value,
+            ATTR_THRESHOLD: self._threshold,
+            ATTR_TYPE: CONF_UPPER if self.is_upper else CONF_LOWER,
+        }
+
+    @asyncio.coroutine
+    def async_update(self):
+        """Get the latest data and updates the states."""
+        if self.is_upper:
+            self._deviation = bool(self.sensor_value > self._threshold)
+        else:
+            self._deviation = bool(self.sensor_value < self._threshold)
diff --git a/tests/components/binary_sensor/test_threshold.py b/tests/components/binary_sensor/test_threshold.py
new file mode 100644
index 00000000000..6af2bbe5b39
--- /dev/null
+++ b/tests/components/binary_sensor/test_threshold.py
@@ -0,0 +1,98 @@
+"""The test for the threshold sensor platform."""
+import unittest
+
+from homeassistant.bootstrap import setup_component
+from homeassistant.const import (ATTR_UNIT_OF_MEASUREMENT, TEMP_CELSIUS)
+
+from tests.common import get_test_home_assistant
+
+
+class TestThresholdSensor(unittest.TestCase):
+    """Test the threshold sensor."""
+
+    def setup_method(self, method):
+        """Set up things to be run when tests are started."""
+        self.hass = get_test_home_assistant()
+
+    def teardown_method(self, method):
+        """Stop everything that was started."""
+        self.hass.stop()
+
+    def test_sensor_upper(self):
+        """Test if source is above threshold."""
+        config = {
+            'binary_sensor': {
+                'platform': 'threshold',
+                'threshold': '15',
+                'type': 'upper',
+                'entity_id': 'sensor.test_monitored',
+            }
+        }
+
+        assert setup_component(self.hass, 'binary_sensor', config)
+
+        self.hass.states.set('sensor.test_monitored', 16,
+                             {ATTR_UNIT_OF_MEASUREMENT: TEMP_CELSIUS})
+        self.hass.block_till_done()
+
+        state = self.hass.states.get('binary_sensor.threshold')
+
+        self.assertEqual('upper', state.attributes.get('type'))
+        self.assertEqual('sensor.test_monitored',
+                         state.attributes.get('entity_id'))
+        self.assertEqual(16, state.attributes.get('sensor_value'))
+        self.assertEqual(float(config['binary_sensor']['threshold']),
+                         state.attributes.get('threshold'))
+
+        assert state.state == 'on'
+
+        self.hass.states.set('sensor.test_monitored', 14)
+        self.hass.block_till_done()
+
+        state = self.hass.states.get('binary_sensor.threshold')
+
+        assert state.state == 'off'
+
+        self.hass.states.set('sensor.test_monitored', 15)
+        self.hass.block_till_done()
+
+        state = self.hass.states.get('binary_sensor.threshold')
+
+        assert state.state == 'off'
+
+    def test_sensor_lower(self):
+        """Test if source is below threshold."""
+        config = {
+            'binary_sensor': {
+                'platform': 'threshold',
+                'threshold': '15',
+                'name': 'Test_threshold',
+                'type': 'lower',
+                'entity_id': 'sensor.test_monitored',
+            }
+        }
+
+        assert setup_component(self.hass, 'binary_sensor', config)
+
+        self.hass.states.set('sensor.test_monitored', 16)
+        self.hass.block_till_done()
+
+        state = self.hass.states.get('binary_sensor.test_threshold')
+
+        self.assertEqual('lower', state.attributes.get('type'))
+
+        assert state.state == 'off'
+
+        self.hass.states.set('sensor.test_monitored', 14)
+        self.hass.block_till_done()
+
+        state = self.hass.states.get('binary_sensor.test_threshold')
+
+        assert state.state == 'on'
+
+        self.hass.states.set('sensor.test_monitored', 15)
+        self.hass.block_till_done()
+
+        state = self.hass.states.get('binary_sensor.test_threshold')
+
+        assert state.state == 'off'