Access to website

Up until 3 weeks ago on my home network I was able to access a certain website now it comes up with “page cannot be displayed”. I can access the website outside the house i.e. from work, I have also pinged the address and I get replies. I have contacted my ISP and they said it was a wireless router problem, I have contacted them and after about an hour of useless advice they could not help me and told me to contact my ISP!!. I have no problem getting out on the Internet anywhere else only the problem with this site. I have emptied temp internet files, cache, checked host files, system restore, checked wireless configuration. Any help out there?