Push notification not working the problem I am having is with Push notifications in Android. 
In order to receive my WhatsApp notifications I need to manually launch the application, which I don't want do. I want to be able to receive my notifications at any time...

I've heard that it might be due to the Push Notification not working so, I decided to download from Google Play the app PNF No-Root which changed the heartbeat interval to 5 minutes (I use WLAN connection) and it didn't work at all (the same for similar apps). I tried looking for other solutions. I went to Settings &gt; Data Usage &gt; WLAN &gt; WhatsApp to check if the Restrict background data box was unchecked, it was unchecked.
I also went to Apps &gt; WhatsApp to see if the box "Show Notifications" was Checked. Went to WLAN &gt; ADVANCED and set "Keep WLAN on during sleep" as "Always". Finally, I launched WhatsApp and all the settings are correctly set for me to receive, but I don't. When I go to Apps &gt; Running &gt; Whatsapp it says that there is 1 Process and to Services (although it shows 1 service sometimes), ExternalMediaManager and MessageService.
My device is a Lenovo A5000 with Android OS 4.4.2
 I don't know what else to try, thanks.
Do you have any power save mode set?

Otherwise Download the app "Wifi settings" and change the DNS Server to Google and hit apply . I hope this will help