Whether you’re building a Plymouth-area new home, renovating an old one, or desperately figuring out what to do because your current hot water heater broke, you’ll need to decide between a storage tank and tankless, or on-demand, hot water heater. 

What’s the difference? 

A hot water tank stores up to 80 gallons of hot water in your home. Typically you’ll find yours in the basement, although smaller homes may tuck them into closets. These tanks keep water hot at all times, but when the hot water runs out you have to wait for the tank to heat up more water. 

A tankless hot water heater, or on-demand hot water heater, heats water when you call for it by turning on a faucet or the dishwasher. Pipes pull cold groundwater into the machine, and gas or electricity heats the water as it flows through the heater and into your faucets. 

So which is better? 

First let’s take a look at the pros & cons for standard Hot Water Tanks: 


  • Less expensive up-front costs
  • Simpler design, making it easier (and cheaper) to install & fix


  • Shorter lifespan than tankless models
  • Keep water hot when not needed, increasing utility bill costs especially in winter 
  • Take up a lot of space, especially in smaller homes
  • Not always enough hot water for everyone to shower 

And then there’s the On-demand hot water heaters: 


  • Twice the lifespan of a tank
  • Use 30-50% less energy than a hot water tank 
  • $100 or more yearly energy savings 


  • As much as 3-5 times more expensive than a standard hot water tank 
  • Takes longer to install and may require retro-fitting 
  • Someone might get a cold shower if you’re taking a shower while doing laundry or running the dishwasher

In short, it depends….

If you already have a hot water tank heater that you’re looking to replace, chances are it’ll be less expensive overall to keep the tank heater even though it’s less energy efficient. But if you’re building a new home, an on-demand system might be a great investment and green solution to water-heating. 

Still can’t decide? Contact the professionals at Dunlap’s Energy to help you weigh your options.