Comments not working

I’ve seen this issue in several posts and have tried all the suggestions but none have helped me.
At this time, the only place from which I can add a comment is when I am in admin, editing the post itself. Other than that, I always get an error reading as follows:
“This is somewhat embarrassing, isn’t it?
It seems we can’t find what you’re looking for. Perhaps searching, or one of the links below, can help.”

I’ve tried turning off all plugins and switching themes, but nothing helped. I’ve checked my page.php and single.php and the comments code is present.
Below is my url:
http://purificwaterusa.com/why-you-want-water-filters-for-your-home/

Anyone have any suggestions?

Thanks