Tankless water heaters: pros and cons

One of the great gifts in undertaking this attempt to renovate Sheep Dog Hollow in a green and economical manner is the way the project has changed and challenged the way I think.

Alexandra Marks

Blogger

Alexandra writes about the "green" and budget-friendly renovation of a 100-year-old farmhouse in south-central Connecticut.

Recent posts

• 02.05.10
  Low-flow toilets have improved
• 02.02.10
  The delicate toilet question
• 01.28.10
  What to do when the new shake roof buckles?
• 01.27.10
  The new generation of green builders
• 01.21.10
  Tankless water heaters: pros and cons

Related stories

• 

  Eco-renovation Are tankless water heaters worth the extra cost?

• The Simple Dollar Save money with a quicker shower. But how much?

• The Simple Dollar Efficient heater insulation puts dollars back in your pocket

Subscribe Today to the Monitor

Click Here for your FREE 30 DAYS of
The Christian Science Monitor
Weekly Digital Edition

So many things that I used to take for granted – water, for instance, both hot in the house and cold out in the pond – I look at quite differently. I see now – in a way that I hadn’t before – that it’s imperative to protect and conserve both whenever possible to ensure that they’ll be plenty for generations to come – even if it’s going to cost me a bit more upfront.

I know, I know, I’m an antediluvian greenie newbie who should have known that all along. But as I mentioned about the “green intimidation factor," some of us just didn’t get it before.

That brings me back to the discussion of tankless water heaters and the bottom-line, cost-benefit analysis approach to them that prompted Consumer Reports magazine to conclude that it’s “probably not” time to switch from conventional models. The reason is that they’re “efficient but not necessarily economical," primarily because their upfront costs are so much higher than conventional-storage water heater tanks:

The tankless water heaters we tested cost $800 to $1,150, compared with $300 to $480 for the regular storage-tank types. Tankless models need electrical outlets for their fan and electronics, upgraded gas pipes, and a new ventilation system. That can bring average installation costs to $1,200, compared with $300 for storage-tank models.

By their calculations, a tankless model is “22 percent more energy-efficient” than a conventional one, which translates into “a savings of around $70 to $80” a year. But “it can take up to 22 years to break even — longer than the 20-year life of many models.”

The article also mentions a survey that found a common complaint among users of the tankless water heaters was their production of “inconsistent water temperatures.”

When you turn on the faucet, tankless models feed in some cold water to gauge how big a temperature rise is needed. If there's cool water lingering in your pipes, you'll receive a momentary "cold-water sandwich" between the old and new hot water. And a tankless water heater's burner might not ignite when you try to get just a trickle of hot water for, say, shaving.

I’ve used an on-demand, gas-fired water heater for years in Italy and did find some problems, but inconsistent temperature was not one of them. In the kitchen, where the tankless heater is situated, I turn on the water, it runs for a moment or two, and I have plenty of stable, hot water.

1 | 2

Next