The Dean of Home Renovation & Repair Advice

Tankless Hot Water Heaters: Should I or Shouldn’t I?

Rinnai Tankless Water Heater

Rinnai Tankless Hot Water Heater

Whether you are building a new home or retrofiiting an older one (like me), take time to evaluate the hot water system.  After all, estimates report that as much as 30% of a home’s energy budget is consumed by heating water.

My new “old house” came complete with an old, rusted gas, tank hot water heater in the attic that was dying…well, dead.  The question was not “should it be replaced?” but rather “should it be replaced with a similar model or a new tankless system?”

A traditional water heater continuously heats water in the tank regardless of whether it is being used.  By comparison, the newer tankless designs heat water only when there is demand for it.  Less stored water to heat…less cost.  And, let’s not forget, more compact and wall-mounted designs.

I did some research on water heating in general—and tankless hot water heaters specifically—and here is what I learned:

Size Matters:  Tankless hot water heaters are available in room (i.e. sufficient for a large bathroom) or whole house sizes.  Calculate how many appliances or fixtures need hot water to determine the best size unit for your home.  For me, a whole-house system was required.

Gas-Operated Tankless Water Heater Diagram

Gas-operated tankless hot water heater diagram.

Fuel Type: Hot water heaters are available in either electric or gas (natural and propane) models.  If you are considering electric, check for voltage and amperage requirements.  The gas version will need some electric to operate, but venting will be the bigger issue.

Location: If you live further north, your ground water will be colder than if you reside in the southern or western part of the U.S.  The temperature of the water will affect the speed and flow.

Know the Flow:  If you think you will need to run the dishwasher while someone else is showering, calculate a larger gallons-per-minute (GPM) to meet your overall water needs.  Take into account water usage, too: A bathroom needs less water than a kitchen; a dishwasher less than a shower, etc.

Look into Rebates: Many utilities offer incentives and you may benefit from state tax credits as well.  Investigate both to make sure you meet the requirements and reap the full benefits.

Rinnai Tankless Water Heater Install

Rinnai Tankless Hot Water Heater Install

Understand the Payback: In general, a tankless hot water heater will cost you more upfront—the average between $800 to $1,150 (plus installation), compared to traditional tank water heaters at $450-$750 (plus installation).  Balance the cost of your unit with your ongoing operating costs.  The estimated operating costs for tankless models can be as much as 24% to 34% less, according to the Air Conditioning, Heating, and Refrigeration Institute (AHRI).

I chose a Rinnai tankless hot water heater for my home.

For more on energy saving home improvements, consider the following Bob Vila articles and videos:

Installing an On-Demand Hot Water System

Five Simple Ways to Save H2O at Home

Smart Water: Faucets, Heaters and Systems

 

  • Alain chiasson

    I wanted electric, but found that one of the largest issues was getting local support for repairs. Because of the high ampeperage, the switching components seem to break more often than expected.

    [Reply]

  • Jeff_wisecarver

    Did anybody calculate a lifespan comparison for each style? I am interested in tankless but I have heard that tankless does not last as long…

    [Reply]

  • Thefrugalhomeowner

    Tankless water heaters are a great way to save on your energy bill. And for that same reason they are also green. If you want some more ideas about how to save money and be green checkout my free ebook called How to Go Green, Save Big, and Live Well. Click on the link below to check it out…

    http://www.frugalhomediy.com/ebook/

    [Reply]

  • Tellitlikeitis

    Tankless water heaters are a money pit. The cost of retrofitting to accomendate to existing plumbing is expensive and isn’t a DIY project either. Also routine maintenance and parts that have to be changed on a annual basis and you won’t know that until the unit stops working. So the money you pay to buy one and have it installed and annual maintence doesnt equal out in the savings. Oh and parts are not redaly available either unless you can wait 3 to 5 business days to take a shower. Also for the money you invested in that heater you could have bought the amount or less in tank type heaters

    [Reply]

  • Anonymous

    Tankless water heaters are a scam, they don’t save you ANY money at all. As a matter of fact, they end up costing more per month than a tank.

    In theory, a tankless will save you money, but in reality, they cost more to operate.

    Ask anyone in the know, you’ll see.

    [Reply]

  • Anonymous

    Tankless water heaters are a scam, they don’t save you ANY money at all. As a matter of fact, they end up costing more per month than a tank.

    In theory, a tankless will save you money, but in reality, they cost more to operate.

    Ask anyone in the know, you’ll see.

    [Reply]