by Robert Moran

Created on: May 26, 2009   Last Updated: May 31, 2009

After almost one year of using a tank less water heater, I can say that it failed to save us money as advertised. It all sounds good, but until you experience the tankless wonder, savings are elusive. It is true that less gas is used to keep water hot and I suppose that in itself is a saving. There are no tanks to fill and reheat, so overall a tank less heater can be cheaper.

The real question involves the plumbing layout in your house. What tankless water heater sales people fail to mention is the need to have a water distribution system under your home. A retention tank will also be sufficient, but the lack of either means a huge expenditure in water. Yes, the water that you anticipate will be hot, but instead arrives cold. Tank less heaters (at least the Rannai) need a draw of 0.6 gallons to begin heating. If you meet or exceed that figure, the device will start to heat immediately. The problems is that all of the cold water arrives first.

Our tankless units has to be on the side of our home that is the farthest point from our baths and the kitchen is half of that distance. Consequently, the cold water takes a long time to reach the bathrooms (4 to 5 minutes) and about 2.5 minutes to get to the sink in the kitchen. When all that time is added together, a lot of water (which is expensive where we live) passes through those pipes before it gets hot!

After complaining to Rannai, and reminding them that they advertised "instant" hot water, I received a diagram showing me how to install a retention tank under the house. We have only a crawl space, so, according to our plumber would be very expensive and not worth the effort. The water in the tank, if we could install it, would get cold in the winter and force the air conditioning to work harder in the summer. We recently went to Home Depot and looked at a device to install under each sink, but the costs were prohibitive and the practically was in question.

Going back on Rannai's web site I noticed it had been sanitized to eliminate the word "instant" from hot water. And, in the store I noticed that all references to instant were also missing.

Another problem relating to water is this-suppose you are taking a bath and want to soak for awhile. What happens when you turn on the hot water? That;s right-it is cold. You shut it off going below the magic 0.6 gallons. The cold water has to be funneled into the commode until the hot come through again. The same scenario occurs in the kitchen when you are doing a pile of dishes and relax the hot water pressure below 0.6 gallon. We call it a "cold sandwich" and they are not pleasant.

Whatever savings realized by the use of less gas are offset by the high volume of water needed to finally feel the hot water promised. Daily usage adds a lot of money to our already high water bill.

With the potential for tankless water heaters, I only hope that the companies that make them are working on something that will solve this problem.

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