William Lund has worked in the water heating industry since the 1980s. For more information about water heaters, tankless water heaters, and hot water circulating pumps visit: Faster Hot Water Instant hot water systems.
Visit Mr. Lund’s blog: Pondering Everything
Tankless water heaters have several advantages over conventional storage type water heaters that store a large volume of water in a tank.
One advantage is that since the tankless unit does not have a tank, there is no continuous heat (energy) loss from the large volume of stored hot water, as there is with a traditional storage type heater. Typically tankless heaters do not have standing pilot lights like tank type units, saving even more energy. There is no question tankless water heaters are more energy efficient.
Another advantage is that you have virtually unlimited hot water, you will never run out. This could be a double edged sword though, as there is a tendency for humans to use what is available. Some users might end up taking much longer showers for instance, leading to an increase in water and energy usage.
This effect was common back when the government provided large tax credits for installing solar water heaters. Homeowners believing they now had cheap hot water tended to use a lot more hot water than before the solar heaters were installed. They used so much more that the monthly water heating bill actually increased in a many of the homes where the units were installed the backup heating elements were being used so much of the time.
A minor advantage that tankless units have over storage units is the size of the footprint. The tankless units take up less space, although I don’t think that is very important to most people.
Obviously there are some disadvantages to tankless water heaters. For one thing, they are much more expensive, and far more complex than a standard water heater. If they require repair it’s likely to be more expensive, and the parts are harder to obtain in some cases. Gas units require a large and more expensive flue, and electric units require very heavy wires because they use so much electricity.
Tankless heaters are typically turned on by a flow switch which turns the heater on when a minimum flow is reached, typically ½ to ¾ gallons per minute. This can be problematic if you need a very small flow of hot water, and can lead to wasting water. Most hot water circulating pumps don’t pump enough water to reliably activate tankless water heaters.
Using a traditional circulating pump will void the warranty on most tankless heaters, since they will cause the heater to turn on and off very frequently and far more than in typical household usage.
One of the biggest problems with the tankless heaters is the fact that they take much longer to get hot water to the fixture than traditional tank type units. You can picture a tankless water heater as a long pipe coiled up over a flame. For the water to get fully hot, it must travel all the way through the pipe. If the water starts out in the middle of the heater for instance, it will leave the heater after only being in the pipe for half the time it would need to reach full temperature. This means that it will take much longer for your water to get hot while you run the faucet waiting for it. It’s pretty clear that this will cause an increase in water being run down the drain, costing the home owner money, wasting one of our most precious resources.
There is however a way to eliminate any of the water from being wastefully run down the drain while waiting for hot water. Use a hot water demand system. A hot water demand system only turns on when hot water is “demanded”. When you are ready for your shower you push a button and the pump sends the hot water from your water heater to your fixture more quickly than if you run the shower at full blast, and the pump shuts off when the hot water reaches it. Thus you save time, water, energy, and money.
Many local water districts offer rebates for demand hot water systems, so check with your local water company, some of the rebates cover the entire cost of a demand system, so in effect, you get a free system!
- Related Articles
- Related Q&A
- Going 'Green' with Environmentally-Friendly Home Improvement Products
- Green Home Improvements and Property Values: Mutually Exclusive?
- Home Improvement - Making Your Home A Happy Haven
- Home Improvement Loans: Now your Dream Home is a Reality
- Home Improvement Resources
- UK Guide To Home Improvement Loan An Easy Way
- An Unbelievable Opportunity That Is What A Home Improvement Loan Is
- Change the Way your Home Looks With Home Improvement Loans




How To Install The Tile Shower Drain
By: Alan Bullington | 11/12/2009Installing a tile shower pan curb is a step-by-step process. The real trick is the important part is buried. Get these three tips for getting the hidden part right.
Tile Shower Pan -- The Top Mud Layer
By: Alan Bullington | 11/12/2009The top layer of the tile shower pan is the final mortar layer. At that point all the tricky part is done. Using a simple mortar recipe and simple tools, the top layer goes on fast...
The Tile Shower Pan Liner Membrane -- Tips For Success
By: Alan Bullington | 11/12/2009The shower pan liner membrane is the key to a shower that doesn't leak. It's built right into the masonry floor. Leave it out and you're going to have water damage around the shower. Here's how it works...
Tile Shower Pan Mud -- Putting It In It's Place
By: Alan Bullington | 11/12/2009Tile shower pans built the traditional way are built with masonry layers. The critical layer in the shower floor is a waterproof membrane. That layer works best if the first masonry layer is built properly.
Tile Shower Pans -- Pre-Slope Or Else
By: Alan Bullington | 11/12/2009Tile shower pans built the traditional way with mortar work well and will for years. The key to a waterproof shower is getting the waterproof membrane installed properly.
The Takagi T-K-Jr Tankless Hot Water Heater – A Product Review
By: William Lund | 11/12/2009Let’s take a brief look at the T-K Jr. the smallest water heater in the Takagi line of tankless water heaters. According to Takagi, it can meet the hot-water needs of a small home or apartment with one or two bathrooms, as well as small commercial applications.
How to Create a Spa Retreat in Your Own Bathroom!
By: Natalia Harrison | 10/12/2009If you're anything like me, after working hard Monday through Friday - the first thing I crave on Saturday morning is a quiet relaxing bath followed by a steam facial and perhaps a manicure. That would usually require a trip to the local day spa, but with a few updates to modernize your bathroom - you can bring the spa feel right to your home!
Golf Trivia Quiz: Who is Tiger Woods?
By: William Lund | 09/12/2009 | Art & EntertainmentI was scanning the headlines this morning and had planned on posting up a new trivia quiz today, but I hadn’t decided on a topic. Well, after a few minutes I had my inspiration! Golf! Tiger Woods is all over the headlines, so I am making this quiz about golf trivia.
Noritz Tankless Water Heater Series 531 and 631 Models – Interesting Facts
By: William Lund | 08/12/2009 | Bath ShowersI was looking over the owners manual for the Noritz tankless water heaters, models: Model N-0631S, N-0631S-OD, N-0531S, N-0531S-OD, and there were interesting thing in there.
PEX Tubing for Residential Plumbing Systems & Demand Pumping Systems
By: William Lund | 01/12/2009 | Bath ShowersI was asked earlier today if a hot water demand system would work with one of these new PEX plumbing systems that use remote manifolds. Well the short answer is yes. You can basically use a hot water demand system with any hot water distribution system.
World and International Trivia Quiz
By: William Lund | 23/11/2009 | Art & EntertainmentI was just browsing the news online, and as usual there are plenty of headlines about Iran, Europe, Iraq, Afghanistan, Somalia Pirates, Brazil and all those other countries. Reading about all the worlds problems got me to thinking maybe I should put together a trivia quiz about international topics.
Green Improvements for Your Kitchen and Bath
By: William Lund | 23/11/2009 | RemodelingIf you are thinking of remodeling your kitchen or bath, or even just making some smaller home improvement to your kitchen or your bathroom, why not go green with your improvements?
Football Trivia Quiz – Test Your Football Knowledge
By: William Lund | 22/11/2009 | Art & EntertainmentAnyone up for a little sports trivia quiz? One of my favorite traditions is to watch the Rose Bowl football game. The Super Bowl is terrific, but I just don’t think you can beat good old college football and my favorite game of all is the Rose Bowl. Looks like the Oregon Ducks might just be there this year. Go Ducks!
Trivia Quiz for Thanksgiving - Twenty Question US History Trivia Quiz
By: William Lund | 20/11/2009 | Art & EntertainmentThanksgiving is almost here, and in celebration of the national holiday I thought I would put together a little twenty questions quiz for those of you who are trivia buffs. I’ll use questions from American History and if I can find some actual thanksgiving questions I’ll include them but you never know what kind of strange trivia I may come up with.
Trivia Quiz for Science Junkies
By: William Lund | 18/11/2009 | Home & FamilyOk, I admit it, I am a science junkie. I’m not really smart enough to understand all of the stuff I read, but I still find it fascinating. It probably goes hand in hand with being a lover of science fiction.