Can a Smart Controller Make an Old Water Heater More Efficient?

A writer looked into whether an aftermarket smart controller can cut energy waste from an older electric water heater. The idea came up while doing an energy assessment on a vacation cabin: water heaters in seasonal homes often keep 40 gallons or more hot around the clock even when nobody's there for days or weeks. Shutting the unit off entirely saves energy but means a long wait for hot water on arrival, which is where a retrofit controller could help by letting an owner turn the heater on remotely before showing up.

The underlying issue is standby loss: even a well-insulated tank loses heat through its walls and pipes, so the heater cycles on and off periodically just to hold temperature, whether or not anyone uses hot water. A water-heater blanket and insulated hot-water piping can cut some of that waste. A smart controller works differently, by tracking when the heater actually runs and adjusting schedules based on when people are home and, potentially, on utility rate periods.

For most households, water heating is typically the second-biggest energy user after heating and cooling, so trimming standby losses can add up over time. This is most relevant for anyone with a second home or cabin that sits empty for stretches, or for anyone whose current water heater runs on a fixed schedule regardless of whether hot water is needed. No specific product names, prices, or savings figures were given, so it's worth researching current controller options and checking compatibility with your own water heater before deciding if one makes sense for your house.