Thanks for replying.

Yes, I have the string in config.

Not using any of the DNN module Dal templates, I am using my own Data classes and sql handlers in App Code that I have used for years and built hundreds of NTier apps with.
My classes work perfectly against the dnn database so nothing wrong there, but obviously something is preventing remote connection.
I have got a little further in  that I am now getting an sql error despite the connection working correctly from Visual Studio
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

We were holding off the DAL 2 templates as we only wanted very simple custom modules without the need for installing templates and having to package and install. We may have to now if we cannot get this fix working

I still believe it should be possible as the error shows it is trying to connect, just need to know what is causing the connection failure