"A connection attempt failed because the connected party did not properly respond after a period of time" using WebClient

I had a similar problem and had to convert the URL from string to Uri object using:

Uri myUri = new Uri(URLInStringFormat, UriKind.Absolute);

(URLInStringFormat is your URL) Try to connect using the Uri instead of the string as:

WebClient client = new WebClient();
client.OpenRead(myUri);

setting the proxy address explicitly in web.config solved my problem

<system.net> 
    <defaultProxy> 
            <proxy usesystemdefault = "false" proxyaddress="http://address:port" bypassonlocal="false"/> 
    </defaultProxy> 
</system.net>

Resolving the “TCP error code 10060: A connection attempt failed…” while consuming a web service

I know this ticket is old, but I just ran into this issue and I thought I would post what was happening to me and how I resolved it:

In my service I was calling there was a call to another web service. Like a goof, I forgot to make sure that the DNS settings were correct when I published the web service, thus my web service, when published, was trying to call from api.myproductionserver.local, rather than api.myproductionserver.com. It was the backend web service that was causing the timeout.

Anyways, I thought I would pass this along.