You may want to look into contacting a local TV or radio station’s investigative reporter. They love stuff like this.
Just a note before you withhold rent: a better practice, to show good faith on your part, is to pay your rent into an escrow account rather than paying anything to your landlord, and inform your landlord in writing of what you’re doing and why. This will hopefully head off any later assertions of “he’s just a deadbeat who doesn’t want to pay his rent,” because you ARE paying rent, just not to your landlord; it’s being held until he fulfills his obligations.
How is it five months when the OP only moved into the residence on March 8 of this year? 
(Three months and change is still too long to be without hot water, though. Time to move and don’t look back.)
Heh, that’s right. Maybe she has a dog, and it’s been 5 dog months.
/science