Water heater research

Tankless vs. Tank Water Water Heaters: Comparison

(Last Updated On: April 12, 2020)

You just got really bad news. Your current water heater is dying. You tried to care for it over the years and keep it living as long as possible, but let’s face it. It’s 11 years old. You’ve already spent hundreds of dollars servicing it. Most tank water heaters only live 8-12 years and maybe 15, if you’re lucky.  Maybe you had a love/hate relationship with it.

It ran out of hot water too fast.  You got cold shots of water in the shower when someone flushed a toilet.  Two people showering in different rooms at once destroyed the experience for both of you.  Two people showering together wasn’t nearly as fun as it sounded because the water didn’t last long enough to make shower time fun. It’s time to let go and move on. Before choosing your next long-term relationship with a water heater, though, you want to ensure you make the right choice.  We’re talking about ensuring the next 10-15 years of your life are as pleasurable as possible.

Below, we’re going to talk about the pros and cons of tankless vs. tank hot water heaters and also something called a hybrid.

Energy consumption fact

Tank Storage Water Heaters

When most people envision a hot water heater, they conjure up an image of a standard tank storage water heater. Tank water heaters are fairly large.  They hold between 20-80 gallons of hot water in the tank.  “Standby loss” is an issue because you have to use energy to keep the tank full of hot water at all times.  If you deplete what’s in the tank, you have to wait until your water heater produces more hot water.


  • Affordable
  • Easy to install


  • Shorter lifespan—8-15 years
  • Once the tank runs out of water, there is a wait time for more hot water
  • “Standby loss.” Energy wasted by keeping the tank full of hot water 24/7
  • Big and bulky—may not be good for someone with space constraints

Tankless Hot Water Heaters

This is a newer version of hot water heaters. Tankless systems heat your water on demand and deliver a constant supply of hot water.  You don’t need to wait for a storage tank to fill up with enough hot water. They can use gas or electric coils, but do have output limits on their flow rate, so if you have many appliances or people taking a shower simultaneously, it may not be able to keep up with demand. To overcome this issue, you can install multiple tankless units or dedicated tankless units for specific high-use appliances, but this can be expensive.

The tankless heater frees up floor space and is  hung on the wall.  The ideal location is on an exterior wall near a gas supply line, water supply line and electrical power source. This is also the easiest and most cost-effective way to run the venting. Gas units typically heat water faster than electric. Installation can be more difficult, as you may need to update your home’s electrical system to support an electric version or run a dedicated gas line to your gas-powered unit.


  • Energy efficient (no “standby loss”)—Energy savings of up to 34% over standard water heater or up to 50% if there are dedicated tankless heaters at each hot water outlet.
  • Longer lifespan—20 years or more. There are easily replaceable parts that can extend the life even further.
  • Very small—great for those with limited space. This can be installed as a dedicated water heater near the shower, under sinks or washing machine.  The size also makes this an excellent option for those who live in very small homes or an RV.
  • Warranties often longer.
  • Excellent option for part-time residences.


  • Equipment more expensive.
  • Installation more expensive and can be more complicated.
  • Long-term energy savings may or may not be offset by the upfront costs.

If you have gas in your home, a tankless unit can save you a lot of money. Also, in some areas, the trend is towards tankless heaters, so if you’re in a neighborhood where this is common, you may want a tankless heater in order to keep your property value in line (if you are thinking about selling your home in the next few years).
Wanna buy a Tankless water heater? Check out Best Tankless Water Heater Reviews

Hybrid Water Heaters

So, you may be wondering what the heck this even is as most people haven’t heard of a hybrid water heater.

Hybrid water heaters feature newer technology, but are more expensive than regular water heaters. However, depending on your current hot water heater and usage, they can save hundreds of dollars in energy costs every year.

Hybrid water heaters combine tank and tankless water heating technology.  Unlike a tankless water heater, it has a tank so that you never have to run out of hot water, which can be an issue with traditional tank systems and  small tankless systems. Hybrid water heaters are also extremely energy efficient.

Hybrid systems usually contain both an electrical element system and a heat pump. The system heats cold water via an electrical heating element and heat pump that pulls in ambient air and extracts the available heat. Depending on hot water demands at any given moment, the system can switch between heating types.  There is a control panel that allows you to also choose what mode makes the most sense for you.  You can generally choose among automatic, efficiency, electric/heater (high-demand setting), or sleep (save on energy when away from home).


  • Energy efficient—Can save on energy costs of up to 62% over a standard water heater.
  • Control panels allow you to operate in different operating modes.
  • Heat pump delivers more hot water, up to 33 percent faster than standard electric water heater


  • Expensive upfront costs—energy savings usually take a few years to pay off.
  • Shorter life span—10 years.
  • Location limited—Need year round temperatures of about 40 degrees-90 degrees Fahrenheit.
  • Need at least 1,000 cubic feet of space surrounding it to operate safely and efficiently.

Also here’s a video from the twin home experts comparing tankless water heaters against normal water heaters

Tankless Reviews was created with the goal of helping people to understand the benefits and practical knowledge related to tankless water heaters. After purchasing my very first tankless heater years back, I realised that other people needed to hear about the incredible money-saving ability of this household item, and wanted to share my lessons with you!