April 28th, 2014

Is a Tankless Water Heater Right for You?

Home Owners Network

Tankless water heaters are one way to make your home more energy and water use efficient.  Manufacturers claim operating cost savings between $50 and $150 per year or more for many families.  Your actual savings will depend on the type and age of your current water heater, its efficiency, and how much hot water you use.  Here are some facts you should consider before purchasing a tankless water heater.

 Tankless water heaters heat water only when you use hot water, compared to storage water heaters that heat water and store it in a tank for when you need it.  The main advantage of a tankless water heater is that no energy is wasted maintaining a tank full of hot water during the vast majority of the day when you don’t need it.  The other advantage is that you won’t run out of hot water so long as you don’t use more hot water than the tankless water heater can produce.

 Some tankless water heaters are designed to provide hot water at the point-of-use, such as for a single bathroom or for the kitchen.  These units provide almost instant hot water because they are close to where you use hot water.  They are more energy and water efficient because no energy and water is wasted running water from a central water heater.  Installing point-of-use tankless water heaters in existing homes may not be practical because each unit must have an individual energy supply and because plumbing pipes usually need to be changed.

 Some tankless models are designed to provide hot water for the entire home.  These larger models can be a practical replacement for storage models in existing homes.

 A tankless water heater must be the correct size to provide all the hot water you need when you need it.  One factor determining the correct size is the maximum number of gallons of hot water you will need per minute.  Smaller models may supply only a shower and a bathroMay Member Newsletter Photoom sink at once.  Larger models can supply two or even three showers at once.


 The other factor determining the correct size is the temperature of the water entering your home.  Tankless units can only increase the water temperature by a certain number of degrees at a certain number of gallons per minute.  This can be a problem in colder areas, particularly during the winter.  For example, if the cold water is 50°, a tankless model may deliver 110° water at 3.3 gallons per minute.  That same model may deliver 5.2 gallons per minute if the cold water is 70°.  You need to determine both the coldest water temperature and the maximum gallons per minute hot water usage to select equipment that will produce enough hot water under all conditions.

 Tankless water heaters use either gas or electricity.  Gas models are more expensive to purchase, install, and maintain than comparable electric models.  The advantages of gas models are that they cost less to use and that they provide more hot water per minute than comparable electric models.

 Replacing a storage water heater with a tankless model may not make economic sense because changes to existing gas and electrical components are often required.  Gas models often require replacing the entire vent system, replacing the gas pipe to the unit, and adding an electrical receptacle near the unit.  This can add several hundred to over one thousand dollars to the cost.

 Electric tankless water heaters require much more electricity than similar electric storage water heaters.  In older homes with 100 or 150 amp electrical panels, larger electric tankless water heaters may require upgrading to a 200 amp electrical panel.  Larger electric tankless models usually require two or three separate 40 to 60 amp circuits.  Depending on the size and location of the home’s electrical panel, providing power to an electric tankless model can add several hundred to over one thousand dollars to the cost.

 An issue with some tankless water heaters is inconsistent water temperature.  Some models do not adjust well to changes in water flow, such as when another water faucet is opened.  This can result in an annoying variance in water temperature.  Another issue with this equipment is that they require more maintenance than storage equipment.  This is particularly true in places with hard or acidic water.  The good news is that if properly maintained, tankless equipment can last up to twice as long as storage equipment.


The Bottom Line

 Tankless water heaters can be a good choice when building or remodeling a home.  They can also be a good choice to replace existing storage water heaters, but installation costs can make tankless models cost ineffective.  Buying a tankless water heater is not as simple as buying a storage model.  You need to do more research on tankless water heater specifications and the conditions in your home so that a tankless water heater provides many years of satisfactory service.

 We’re here to help at Homeowners Network.  Use our ‘Ask The Experts’ service if you need help.  Please include as many details as possible about your situation so we can provide you with our best advice.

 If you need a qualified technician to help you, try our “Find a Contractor” referral service.  Log on to your Homeowners Network account to access the “Find a Contractor” page.

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