Tankless vs. Tank Water Heater


You could be in one of several situations as you consider purchasing a tankless water heater:
You might be moving into a new home and wanting to save space in it.
You might have a tank heater that has given up the ghost and you are ready for a change.
Or you might just wonder what all of the fuss is about as many consumers make the switch to tankless heaters and you want to learn what a lot of the developed world has known for decades — tankless heaters give hot water fast and don’t take up space to do it. They also don’t heat water unless asked to, saving you money on energy dollars.

Here are a few pros and cons of tankless heaters:

Tankless Water Heater Pros

  • Deliver a constant supply of hot water because there is no lag time as a tank re-fills once depleted.
  • Produce energy savings of up to 35%, especially in homes that use 40 gallons or less of hot water per day. Even for homes that use massive amounts of hot water, the savings run at about 10%. The more tankless heaters installed, the greater your savings.
  • Tankless heaters last longer than tank heaters, averaging 20+ years, as opposed to 7-15 years for tank heaters.
  • Their parts are easily replaceable as well.

Tankless Heater Cons

  • Flow rates limit the amount of hot water running through the pipes at any one moment. Thus, even the largest tankless heater might not meet the demands of multiple uses in a large home. One shower + one dishwasher running=maximum output for most tankless heaters, for instance. The answer? Install two tankless heaters.
  • The need for more than one tankless heater in many applications means higher start-up costs.
  • They need to be near to remote bathrooms and hot tubs to be effective. You can’t install a massive one under the sink and think that it will give consistent hot water to the upstairs shower 100 feet away.
  • Some gas models have a constant pilot light, reducing your energy savings.

Now, a consideration of the pros and cons of tank heaters:

Tank Heater Pros

  • Most homes are already built to hold these types of heaters.
  • If you purchase a heater of adequate size, you should never run short of hot water.
  • The start-up costs are lower than for tankless heaters.
  • They are more energy-efficient than ever, reducing the savings that tankless heaters give.

Tank Heater Cons

  • They heat water all day and night, whether or not you are using them, resulting in inefficiency.
  • They are difficult to repair yourself and require maintenance to achieve their maximum life span.
  • Re-lighting a pilot light can be difficult and dangerous.
  • If a lot of hot water is used, recovery time can take up to ½ hour, especially for electric models.
  • They take up large amounts of space, and gas heaters cannot be in any living areas, etc.

Finally, let’s consider the wonders of a couple of newer entries to the water heater roster — the hybrid heater and the solar heater.

Hybrid Water Heaters


The new hybrid heaters take heat from the ambient air and compress it. This makes your heater much more efficient. Some estimates say that a hybrid heater can save you 60+% on your energy bill, a huge amount, especially when multiplied over 10 years’ time. Purchase of these heaters will also give you a tax break.

That said, these hybrid heaters are very pricey. If you are going to live in your home for many years, they make economic sense. If not, you might not recoup your energy savings for several years. If spending four figures on a hot water heater makes sense for you, consider a hybrid model.

Solar Water Heaters

The advantages of these heaters are obvious, especially if you live in a sunny area. They cut down on energy use, which helps the environment, they save you lots of money, and they are growing more efficient by the day as solar cells continue to evolve.

Need numbers?
A solar heater could chop up to 90% of your energy use, given that heating hot water comprises much of your energy bill. These savings will only grow as energy costs rise per unit. You also can receive rebates and tax breaks with these heaters.

As with other “smart” energy choices, the start-up costs for solar heaters is high, especially if you are not in a very sunny area. You will need more panels to pull in more solar energy in less sunny climates.

Both hybrid and solar heaters present a dilemma for anyone that wants to go green: are you willing to pay far more upfront to save money for years down the road?