Additional work may be required to install your new water heater. The first thing our experts will do is assess the situation and tell you exactly what work will be required and how much it would cost. Don't worry, you're not in for any surprises! Situations that could require additional work. It's hard to get at your water heater, so the tank must be moved. There's no cold water supply valve or the valve must be replaced. Your home's electrical system is not up to code or cannot handle the new water heater you want to install. You're replacing an oil- or gas-fired water heater with an electrical water heater. Close