I have an electric HWH that is controlled by FPL load management system. I am going away for 3 weeks and want to shut off the water supply during that time. Can the electric to the HWH be left on with the water supply shut off? Will the HWH overheat and expand until it leaks or explodes. What are my options if any.

Hi Spenser

I'd suggest shutting off the power and shutting off the water into the heater if you can... should be a water heater breaker at the panel to shut off!

Heck, I'd one better that and I would tell you to shut off the water MAIN supply to the entire house... can't hurt to protect the whole house, right? In this case, I would also shut the power off to the water heater at the breaker as again, no need to pay to maintain temperature for any reason while you are away.

With all that being said, to answer your question directly, no, if you shut off the water supply into the heater and let it sit for 3 weeks with power supplied as normal there is no issue or concerns for you!

Mark