Tank vs. Tankless Hot Water Heaters: Which is Right for You? 

Starting your day with a morning shower, you’re counting on the hot water to shake off the out-of-bed grogginess.  That wake-me-up hot water comes from a heater, traditionally stored pre-heated in a tank.  Nowadays, more of these morning people are considering the benefits of a tankless hot water tank, or hot water on demand.  Tankless hot water save space and energy costs, so it must be the way to go, right?  Well, coming to an informed decision between Tank vs Tankless hot water heater requires a bit of research, which we’ll help you with.  As you’d suspect, each option has its own operating profile and unique pros-and-cons. 

Tank Hot Water Heaters: A Reliable Standard 

This is the hot water you grew up with.  A hot water tank holds a set amount of hot water for immediate use. Think of heating water in a pot on the kitchen stove.  It works by heating water within a tank and maintaining a constant temperature.  There are heating elements, a thermostat, a pressure release valve, and a drain valve.  When you turn on a hot water tap, the heated water flows out of the tank and into your plumbing system, eventually to your faucet. 

Tanked hot water heaters are low maintenance, mostly self-maintaining.  Once a year, the water heater tank should be flushed and cleaned, preventing buildup of heavy sediments on the bottom of the tank.  As a safety check, the T&P valve on the side of the water heater should be tested to make sure that it can drain pressure and water. 

The water within a tanked hot water tank is mainly heated by one of two sources, electric or gas.  Electric hot water tanks cost less, are easier to install and maintain, and are more environmentally friendly than gas.  Gas heaters use either natural gas or propane as the fuel source, require proper ventilation, and are more energy efficient than electrical hot water tanks. 

With this setup, there are inherent drawbacks of tanked water heaters.  The most obvious is energy usage.  Whether the water is used or not, energy is being expended to keep that water up to temperature.  There is risk of water damage.  Though rare, water tanks can leak or break apart during natural disasters.  Lastly, the ability to provide hot water is limited by the capacity of the tank.  As a father of three teenage girls once remarked to us, “This tank ain’t big enough for my family!” 

On the flip side of the coin, there are several advantages to hot water tanks.  Of most concern to people is a consistent hot water supply.  You can run the dishwasher and washing machine at the same time, and still take a hot shower.  Hot water tanks are also reliable, with modern tanks having more than a century of development and refinement behind their design.  Finally, of great interest to most people, hot water tanks are usually more affordable to purchase and install, compared to tankless water heaters. 

 

“If you’re seriously debating between the two, you should contact a professional who can analyze your particular situation, define your goals, and avoid performance and installation issues.  You only want to spend money on this once.”  Jason Hanleybrown, CEO of Fast Water Heater. 

 

Tankless Hot Water Heaters: A Modern Solution for Endless Hot Water 

Unlike traditional tank water heaters that store hot water, tankless water heaters heat water instantly when needed.   Tankless water heaters (or on-demand, instant, or instantaneous water heaters) heat the water from two heat exchangers located in the center of the water heater.  Tankless water heaters are modern and efficient solution for heating water in your home. 

The most obvious advantage of tankless hot water heaters is heating water upon demand, only when needed, reducing energy consumption.  These on-demand hot water heaters provide a continuous supply of hot water, ideal for household with high demand.  For those thinking long term, tankless hot water heaters last longer than traditional tanked water heaters.  Finally, their compact design allows installation in tight spaces. 

On the flip side, tankless hot water heaters are more expensive to purchase and install.  Then, tankless hot water heaters have a lower flow rate, meaning multiple high flow appliances can not be run at the same time.  Tankless water heaters are maintained by cleaning the inlet filter and the air filter, inspecting the water heater, and descaling and flushing the unit.  Finally, installing a tankless hot water tank is not a Do-It-Yourself project.  Tankless hot water tanks require the skill of pros, especially for the warranty to remain in-tact. 

Given this, how does tank vs. tankless hot water heaters stack up against each other? 

Initial Cost: A tankless hot water heater costs more in the beginning.  Both the equipment and installation costs are greater.  Expect to pay double what you would pay when purchasing and installing a tanked water heater. 

Energy Costs: This ultimately depends upon the energy rates in your area and the hot water usage within your house.  In lab testing, tankless water heaters are up to 34-percent more energy-efficient than tank models in homes using less than 41 gallons of water per day.   

Hot Water Usage: This depends upon your family and their hot water usage profile.  Larger households with high water demand will probably benefit from a tankless water heater. 

Equipment Life: This is where tankless shines.  Most hot water tanks carry a six year warranty, and you’re doing good if they make it to ten years.    With tankless hot water systems, it’s not usual to get twenty years of service. 

Putting all of this into the mathematical blender, the general payback for a tankless hot water system is around 12-15 years.  So, tankless is better over the long run, but you need to be patient. 

Given all of this, are you ready to move to the promised land of tankless water heaters?  Well, there are several key considerations before you.  First, this isn’t a weekend Do-It-Yourself project.  City codes and warranty requirements necessitate a licensed plumber perform the installation.  If going with gas, then a qualified technician will need to update your gas line, perhaps even upgrading for the higher flow rate.  Proper ventilation is critical for safety.  If going with electrical, then a dedicated power line is needed.  In some cases, the main power box needs to be upgraded to 200 amps to handle the additional draw. 

The most obvious ingredient, water, is the next consideration.  Tankless water heaters require specific flow rates to function efficiently.  Your home’s plumbing system must be able to deliver adequate water flow to the unit.  Then, hard water can reduce the lifespan of a tankless water heater. A water softener may be necessary to protect the unit and improve its performance.  

Finally, local building codes and regulations are the final point.  City hall usually doesn’t have a sense of humor when Do-It-Yourselfers screw up their tankless hot water installation.  There are specific requirements for tankless water heater installation, as well as permits.  (Think of installing on the sly without telling city hall?  Eventually, they do find out.  Then, you get the fun of paying the permit fees, along with fines.)   

In summary, changing from a tank water heater to a tankless one is a significant undertaking. It needs careful planning and professional installation. By thinking about the factors above and talking to qualified professionals, you can make the transition easier. This way, you can enjoy a more efficient and eco-friendly water heating system.