Check the following:

• Make sure your mobile device is connected to the Internet.
• Make sure you're using a supported mobile device. Your Pulsense product will pair only with devices that use Bluetooth Smart (Bluetooth 4.0). Other devices are not supported. The iPhone 4s, iPhone 5, iPhone 5c, iPhone 5s, iPhone 6, and iPhone 6 Plus with iOS 7.1 or later support Bluetooth Smart (Bluetooth 4.0).
• Make sure Bluetooth is enabled on your mobile device.
• Make sure you pair your device from the PULSENSE View app, not from your mobile device's Bluetooth settings. To pair your Pulsense device, open the PULSENSE View app, tap, tap Pairing, then tap Add new device. Select your Pulsense device, then follow the on-screen instructions.
• If your Pulsense device was paired with another mobile device, delete pairing with your Pulsense device in the PULSENSE View app on both mobile devices, turn off Bluetooth pairing with your Pulsense device on both mobile devices, then unpair the Pulsense device. To unpair the Pulsense device, do the following:
  
  [PS-100]
  Connect your charging cradle to a computer (or the device's AC adapter), then place your PS-100 into the charging cradle. Firmly tap your PS-100 until the blue lights flash.
  
  [PS-500]
  Double tap the watch face to display the menu, press the B button until you see the Bluetooth menu, press the A button, then press the A button again.
  Try pairing your Pulsense device with your mobile device again. To pair them, open the PULSENSE View app, tap, tap Pairing, then tap Add new device. Select your Pulsense device, then follow the on-screen instructions.
• Make sure there is no interference in communication between your Pulsense device and your mobile device.

• No. Only one Pulsense device can be registered to a smartphone at a time. To register a new Pulsense device with your smartphone, you’ll need to cancel pairing with the previous Pulsense device. To cancel pairing, delete pairing in the PULSENSE View app for the previous Pulsense device, then disable Bluetooth pairing with the previous Pulsense device. Pair with the new Pulsense device.

How to Disable Bluetooth Pairing

PS-500

Double tap the watch face to display the menu, press the B button to select the Bluetooth menu, press the A button, then press the A button again.

PS-100

Connect your charging cradle to a computer (or AC adapter), then place your PS-100 into the charging cradle. Firmly tap your PS-100 until the blue lights flash.

• Move your Pulsense device near your mobile device and wait a few minutes for the devices to reconnect; your Pulsense device may be out of range for a Bluetooth connection with your mobile device.

If that does not help, try the following:

• Turn off Bluetooth on your mobile device, then turn it on again. Wait a few minutes for the devices to reconnect.
• Turn your mobile device off, then turn it on again. Wait a few minutes for the devices to reconnect.

• Set up the Bluetooth connection again. Do the following:
  
  1. ①Delete pairing in the PULSENSE View app. Open the app, select Pairing > >, then Delete.
  2. ②Unpair the Pulsense device.
     [PS-100]
     Connect your charging cradle to a computer (or the device's AC adapter), then place your PS-100 into the charging cradle. Firmly tap your PS-100 until the blue lights flash.
     [PS-500]
     Double tap the watch face to display the menu, press the B button until you see the Bluetooth menu, press the A button, then press the A button again.
  3. ③Turn off Bluetooth pairing with your Pulsense device on your mobile device. See your mobile device's Bluetooth settings to unpair the Pulsense device.
  4. ④Pair your Pulsense device with your mobile device again. To pair them, open the PULSENSE View app, tap, tap Pairing, then tap Add new device. Select your Pulsense device, then follow the on-screen instructions.