Hot Water Tank
Traditional tank-style water heaters are deeply familiar to their installers and repairmen, and they remain in use in part.
Whether powered by natural gas, electricity, propane, or oil, storage water heaters function in pretty much the same way. The unit heats and reheats a volume of water stored within an insulated tank. When a plumbing fixture or water-using appliance calls for it, hot water exits the tank from the top, while cold water enters from the bottom to replenish the tank.
Conventional water heaters operate 24 hours, whether you need hot water or not. When water in the tank cools down below a certain threshold, the appliance reheats the same water, effectively wasting energy in the process. With more insulation and less standby heat loss, tank-style units now waste a lot less energy than before.
If you have a gas water heater and you’re replacing it with a gas water heater, you can expect installation to cost about as much as the unit itself around $300 to $500. Switching from one fuel type to another, from electric to gas inevitably adds complexity and cost, but not as much as you might think. Because storage tank water heaters don’t usually require any wiring or piping modifications.
There’s a common complaint against storage units: Because their tanks are limited and their water-heating process isn’t instant, it’s possible to run out of hot water temporarily. If you always running out of hot water, that means you need a bigger unit.