Kibana service running, but no response from browser?

I've installed kibana before, but this time I cannot get any response from a browser? I see port 5601 listening via netstat and the firewall is disabled. I can get to ntopng via browser, which is running on port 3000, but I get no response from http://myserver:5601
A port scan also shows nothing from port 5601, only 22 and 3000 are open/responding.
This is a CentOS 7 box.

How can I troubleshoot this problem?

Thanks!

What do the KB logs show?

Good call Mark. It would appear that ES is my issue. Log is filled with >

name":"Kibana","hostname":"localhost.localdomain","pid":21912,"level":40,"msg":"No living connections","time":"2015-08-26T18:03:56.283Z","v":0}
{"name":"Kibana","hostname":"localhost.localdomain","pid":21912,"level":30,"msg":"Unable to connect to elasticsearch at http://localhost:9200. Retrying in 2.5 seconds.","time":"2015-08-26T18:03:56.283Z","v":0}
{"name":"Kibana","hostname":"localhost.localdomain","pid":21912,"level":40,"msg":"Unable to revive connection: http://localhost:9200/","time":"2015-08-26T18:03:58.789Z","v":0}