diff -u b/src/Plugin/monitoring/SensorPlugin/ConfigValueSensorPlugin.php b/src/Plugin/monitoring/SensorPlugin/ConfigValueSensorPlugin.php
--- b/src/Plugin/monitoring/SensorPlugin/ConfigValueSensorPlugin.php
+++ b/src/Plugin/monitoring/SensorPlugin/ConfigValueSensorPlugin.php
@@ -25,11 +25,6 @@
   /**
    * {@inheritdoc}
    */
-  protected $configurableValueType = FALSE;
-
-  /**
-   * {@inheritdoc}
-   */
   protected function getValueDescription() {
     return (t('The expected value of config %key, current value: %actVal',
       array(
@@ -93,12 +88,2 @@
 
-  /**
-   * {@inheritdoc}
-   */
-  public function getDefaultConfiguration() {
-    $default_config = array(
-      'value_type' => 'bool',
-    );
-    return $default_config;
-  }
-
 }
reverted:
--- b/src/Plugin/monitoring/SensorPlugin/UserFailedLoginsSensorPlugin.php
+++ a/src/Plugin/monitoring/SensorPlugin/UserFailedLoginsSensorPlugin.php
@@ -25,11 +25,6 @@
   /**
    * {@inheritdoc}
    */
-  protected $configurableValueType = FALSE;
-
-  /**
-   * {@inheritdoc}
-   */
   public function getAggregateQuery() {
     $query = parent::getAggregateQuery();
     $query->addField('watchdog', 'variables');
diff -u b/src/Tests/MonitoringUITest.php b/src/Tests/MonitoringUITest.php
--- b/src/Tests/MonitoringUITest.php
+++ b/src/Tests/MonitoringUITest.php
@@ -248,14 +248,16 @@
       'description' => 'Sensor created to test UI',
       'value_label' => 'Test Value',
       'caching_time' => 100,
+      'value_type' => 'bool',
       'settings[key]' => 'threshold.autorun',
       'settings[config]' => 'system.cron',
     ), t('Save'));
     $this->assertText(SafeMarkup::format('Sensor @label saved.', array('@label' => 'UI created Sensor config')));
 
-    // Check the value type has the default value.
-    $sensor_config = SensorConfig::load('ui_test_sensor_config');
-    $this->assertEqual($sensor_config->getValueType(), 'bool');
+    // Go back to the sensor edit page,
+    // Check the value type is properly selected.
+    $this->drupalGet('admin/config/system/monitoring/sensors/ui_test_sensor_config');
+    $this->assertOptionSelected('edit-value-type', 'bool');
 
     // Try to enable a sensor which is disabled by default and vice versa.
     // Check the default status of cron safe threshold and new users sensors.