Where are you going to get 220VAC power for a residential water heater? Not a smart thought IMHO. Replacing for 500 dollars? Not likely especially since it is such a simple matter to troubleshoot and fix it. The 120VAC electric element needs several hours to heat the water, it needs 120VAC power to it. All these things can be easily checked with a VOM. The gas side needs flowing propane. In other words do you actually have gas in the tanks? Do you have gas flow to other things like the stove? Does your heater have a standing pilot that you must light or is it electronic ignition? Standing pilot you need to get the thermal couple hot to generate the electrical current necessary to hold the gas valve open. Thermal couples are cheap and easy to fix if that is a suspect.