Got a call for no hot water, customer had a small electrical fire the night before and fire dept shut off gas to the house. I went to light pilot and I noticed the plastic rings around the water pipes that distinguish hot and cold were melted. Checked draft with a lighter and had none. When I pulled the smoke pipe out of the chiminey I noticed that the person who installed water only busted a hole in the first wall of the block, and didn't go through the back wall. The water heater was installed 3 years ago.