Apple Yosemite Server configure secure website

I am running Server 4.0.3 on a Mac Mini running Yosemite 10.10.2 and am having trouble with setting up a secure website.

In my DNS, I have a primary zone with a machine record for my website,e.g. www.abccompany.com. In the website settings on Server, in addition to the default website of Server Website and Server Website (SSL), I have my website, www.abccompany.com for all addresses on port 80. I can access this from both within my lan and from the wan.

I have added an additional site for www.abccompany.com but as a secure website on port 443. If I try and go to this website securely using http://ift.tt/1LbDvyG, I get shown my routers log in page which happens to be 172.16.20.254. The server's IP address is 172.16.20.1.

Does anyone know why Server is forwarding requests to the secure site of www.abccompany.com to my router's IP address and how to fix it.

Many Thanks

Paul