Hopefully someone can help me with this.

My webserver has been offline for about 6 months since some construction in my house.

I turned it back on the other day - all seemed fine - the website it was hosting was fine.

I did some updates (apt-get update and upgrade) - all still seemed fine.

The next day the website stopped working.

Now what I am getting is sometimes the site loads sometimes it doesnt. On an iphone I get an error 502 bad gateway, on a computer I get the page cannot be displayed.

Any ideas what this could be?