Setting up HTTPS DNS with Namecheap and Heroku
If anyone is still having problems and your website opens without HTTPS. There is a line of code in rails applications which you should uncomment. Go to config/environments/production.rb In this file you will find a commented line "config.force_ssl = true". Uncomment this line and your application will always open up with https
Combination of two answers above will solve the problem for Rails applications:
Go to Namecheap and add the two following CNAME's:
Type: CNAME
Host: @
Value: www.yourdomain.com.herokudns.com
TTL: Automatic
Type: CNAME
Host: www
Value: www.yourdomain.com.herokudns.com
TTL: Automatic
And then follow second answer: "Go to config/environments/production.rb In this file you will find a commented line "config.force_ssl = true"."
That should do the trick.