As a home inspector one concern I see often is the installation of water heaters by homeowners or unlicensed handymen. Improperly installed water heaters cause fires, floods, and even deaths. In 2007 there were an estimated 7,200 reported home structure fires involving water heaters. 

Installation of water heaters should ONLY be performed by a Licensed Plumber and never by the weekend warrior. Numerous installation issues are noticed during my inspections that indicate that other issues will arise because of the work performed.

If you need to have work like this performed make sure that you get a Licensed professional to do the install.