Add this to your Web Config
<system.web>
<httpRuntime executionTimeout="180" />
</system.web>
https://msdn.microsoft.com/en-us/library/e1f13641(v=vs.85).aspx
Optional TimeSpan attribute.
Specifies the maximum number of seconds that a request is allowed to
execute before being automatically shut down by ASP.NET.This time-out applies only if the debug attribute in the compilation
element is False. To help to prevent shutting down the application
while you are debugging, do not set this time-out to a large value.The default is “00:01:50” (110 seconds).