How to get emergency mode in LG E455? I can't boot my phone but I can see the lg logo.  

So my question is how to get emergency mode in LG E455?
According to this link, you can reach recovery by holding the power button and the volume button for a few seconds when the phone is turned off completely.

From there you'll probably be able to reset your phone to factory defaults to make the phone bootable again. This probably means losing all user data stored on the phone. If a factory reset does not help, you might need to download your ROM (=Android version of your phone) from the Internet and install it using the recovery. If you can't do this in your recovery or you can't get it to work, I recommend you contact LG support.