Comparing Tank and Tankless Hot Water Heaters

Tai Irwin
16 Aug 2013

BY Tai Irwin / 0 Comments

Differences Between Tankless Hot Water Heaters And Conventional Hot Water Heaters

North Shore Hot Water ServiceThere is much controversy among consumers over which hot water heater system, tank or tankless, provides the largest overall return of investment and is most hassle free. Differences between the cost, efficiency, and longevity of tank and tankless hot water heaters are the main subjects of dispute. Ultimately, a consumer will need to consider these issues to determine whether the tank or tankless water heater system is best suited for their individual needs.

How do the two systems work?

A traditional tank hot water heater, or storage hot water heater, operates by storing hot water in the unit itself until the hot water is used somewhere in the house or building. Common tank hot water heaters hold between 20 and 80 gallons. The tanks are insulated to lessen heat loss while the water is unused. Tank hot water heaters may use electric, natural gas, or liquid propane.

Unlike tank hot water heaters, tankless hot water heaters or demand type hot water heaters do not hold water in the unit, rather the water is flash heated as it passes through the unit. The water is heated only when there is an immediate need. Tankless hot water heaters may use electric or gas burners.

What is the difference in cost between tank and tankless hot water heaters?

Tankless hot water heaters are much more expensive to purchase and install than tank hot water heaters.

Which is more efficient?

The general consensus is tankless hot water heaters are more energy efficient than tank hot water heaters. Tankless hot water heaters are around 24% to 34% more efficient than tank hot water heaters in homes using 41 gallons of water or less daily. 41 gallons is considered to be conservative water use. For homes using 81 gallons of water daily (which is considered heavy usage) a tankless water heater is 8% to 14% more efficient.

However, it should be mentioned that tankless hot water heaters have a slow flow rate of around 2 to 5 gallons per minute compared to tank hot water heaters. This makes it difficult to operate multiple hot water appliances simultaneously. For this reason, some consumers may need to purchase additional smaller tankless systems for appliances.

What are the life expectancies of each?

Tankless hot water heaters have a longer life expectancy than tank hot water heaters. A tankless hot water heater lasts longer than 20 years whereas tank hot water heaters have an expectancy of 10 to 15 years. Tankless hot water heaters require more routine maintenance than their counterparts to ensure it reaches that expectancy, however.

When deciding between a tank and tankless hot water heater, the consumer must consider the differences in cost, efficiency, and longevity of the two. A tankless system may cost more initially and require regular maintenance, but it is more energy efficient and will last longer. A tank system may not be as energy efficient and may have a lower life expectancy, however it is much less expensive in upfront costs and requires less maintenance.

Need a new hot water heater for your North Shore home? Call Tai Irwin Plumbing 02 9451-1863 and schedule a service call today!