How a Tankless Water Heater Works
Overview of the Tankless Hot Water Heating System
Most people in North America currently use a storage tank water
heater to provide hot water in their homes. At Tanklesswater.com we
have a better solution and we are here to help you understand the
pros and cons of a tankless water heater. A storage tank water
heater keeps water hot 24 hours a day, even while you’re at work or
sleeping. A tankless hot water heating system, on the other hand,
does not store hot water. It heats the water as you use it,
providing endless hot water. There are additional links at the
bottom of this page which can help you in the selection of specific
units that would be best for your home. Please review this
section thoroughly.
What are the advantages of a tankless system? A
tankless water heater also known as point of use water heater or on demand
units, turns on when you open a hot water faucet and turns off when you close
the faucet, so the energy that is consumed is only for the hot water that is
being used. Since there is no storage of hot water and thus no constant heating
and re-heating of stored hot water, you’re not wasting energy heating water when
you don’t need it, such as when you’re sleeping or not at home. This energy
savings translates to dollar savings for you and reduced impact on our
environment. Furthermore, since a tankless water heater heats the water as you
use it, you can have an endless supply of hot water, provided you size the unit
appropriately. Tankless water heaters are also designed to last for 20 years and
are smaller than tank units.
How
do they work?When a hot water tap is
opened, the cold water enters the heater and triggers the heating
elements or burners to turn on. Your hot water tap acts as an
ignition key for the energy used to heat the hot water you need. The
water is then heated as it flows through the heating elements or
heat exchanger. As you change the water flow, a water valve or
thermostat controls the heating elements or burner flame to maintain
a constant temperature. The amount of energy used is always
proportional to the volume of hot water being used. When the hot
water tap is turned off, the system shuts down.
The water temperature can be adjusted to produce outlet temperatures
ranging from 100° to 140° F.
How can a tankless water heater heat water instantly?
When you open a faucet, the flow of the water triggers the heater to
turn on. Whether you use gas or electricity, the powerful gas
burners or electrical elements will turn on, rapidly heating the
water as it passes through the unit. The water is heated instantly,
and the time it takes to obtain hot water is directly related to the
distance the hot water has to travel from the water heater to where
hot water is being used. The burners or elements then shut down when
you shut off the hot water. The energy that is consumed is only for
the hot water that is being used.
How much money can I save?
Depending on which model of tankless water heater you purchase, and
what size storage tank you have now, and if it runs on gas or
electricity, you could save anywhere from 11% to 69% off your hot
water heating bill. How? Most homes use hot water for a cumulative
total of about one hour per day, yet they typically keep 40 or 50
gallons (oftentimes more) of water hot 24 hours a day. Having a
system that eliminates the storage and heats water only as you use
it can dramatically reduce your energy consumption.
Can it really provide an endless supply of hot water?
Yes. Because storage tank water heaters store a finite amount of
water, when that amount is used up your shower goes cold and you
have to wait for the heater to heat the water back up (this is known
as recovery time). Because a tankless water heater heats the water
as it passes through the heater, you can never run out, provided
flow limitations are not exceeded.
Are there other benefits of a tankless water heater?
There are many advantages of having a tankless water heater in your
home. Besides the money savings, endless hot water and smaller
impact on the environment, a tankless water heater:
Is very small and can hang on the wall, thereby saving you
valuable floor space.
Is designed with replaceable parts and is built with such
materials as copper, stainless steel, and aluminum (the
AquaStar) so as to last a lifetime. Energy savings is only one
segment of savings—with proper care this could be the only water
heater one needs in a lifetime.
Is almost entirely recyclable, so if you ever decide to
replace it, it doesn’t have to go to the landfill.
Will not develop a corrosive leak like a storage tank water
heater, saving you from expensive water damage in your home.
Note: A tankless water heater can leak if it is exposed to
freezing temperatures or has a manufacturing defect.
Maintains its efficiency throughout the lifetime of the unit.
Storage tank water heaters decrease in efficiency over time due
to mineral build-up inside the tank. This is due to the fact
that storage tank water heaters store hot water, giving those
minerals a chance to settle out and bake from the heat onto the
walls of the tank, and onto the heating element in electrical
models, thereby reducing heat transfer.
Will I still get the hot shower I’m used to now?
Yes, provided you buy the right tankless heater for you (visit the
Buying Guide to select the right model for you). Tankless water
heaters are able to function at a variety of temperatures that you
can choose, and can produce hot water at the same flow rate as your
standard single-headed shower provides now (since 1992 all
showerheads are designed to deliver a maximum of 2.5 gallons per
minute, as mandated by federal legislation).
Will one tankless water heater do my entire house?
Yes. You must choose the size model to suit your home’s hot water
needs, which is based upon the maximum flow of hot water you need at
any one time (visit the Buying Guide to
select the right model for you). We sell tankless water heaters that
are capable of handling one shower at a time and others that can
sustain a maximum of two showers at a time.
What if I have very hard water?
Since tankless water heaters do not store hot water, minerals do not
have as much of a chance to settle onto the heater. Therefore, you
won’t see the same corrosive or scale build-up problems with
tankless water heaters that you do with storage tank water heaters.
And it is fine to use a water softener with a tankless water heater,
if you choose.
What limitations do tankless water heaters have?
Because this type of water heater heats the water as you use it, the
volume of hot water that it can deliver is directly correlated to
the amount of its energy input. The bigger the burners or heating
elements in the unit, the higher the volume of hot water that it can
deliver. Today tankless water heaters come in various sizes to suit
most homes’ needs. Even if you need to be operating multiple showers
at once, tankless water heaters can keep up (visit the
Buying Guide to select the right model for you).
How do I properly size a tankless water heater for my home?
You need to choose the model that can deliver the volume of hot
water to meet your needs. The best method for sizing this type of
water heater is to know how many showers each model can run
simultaneously. We have models that can run either one or two
showers at a time. Our most popular sized model is the one that
delivers one shower at a time. (Remember, although it will only
deliver one shower at a time, it can do so endlessly, shower after
shower after shower.) Visit the
Buying Guide to select the right model for you).
Can I fill a hot tub with a tankless water heater?
Yes. Because tankless water heaters provide an endless supply of hot
water, you can fill a tub of any size. It is only a question of
time, meaning that our larger units can fill a tub faster than our
smaller units. Keep in mind that some tubs draw water at high flow
rates, so it may be necessary to limit the flow so that the tankless
water heater can adequately heat the water that is being called for.
Is this a new technology?
No. Europe, Asia and South America, where energy costs are more
expensive than here in the U.S., have been using tankless water
heaters for 75 years. Controlled Energy Corporation has been selling
and supporting tankless water heaters in the United States since
1979. However, most Americans are just now learning of this
technology and its benefits.
What is a point-of-use water heater?
A point-of-use water heater is a very small water heater, tank or
tankless, that is designed to be installed at the point of use,
thereby eliminating a long pipe run. They are mostly sized to supply
hot water to one specific application, usually a sink. These can be
either a mini storage tank or a tankless water heater. A common
application is a remote sink, such as a bathroom in an office
building or a service station. The other sensible application is for
distant sinks in the home that typically take too long to receive
hot water.
What are the advantages of a point-of-use water heater?
Point-of-use water heaters are usually used for one of two reasons.
One is to supply hot water to a remote location that is not served
by a larger water heater. The other is to eliminate the wait time
for hot water you may have at a particular faucet. Both offer the
advantage of not having to wait for hot water. You can install a
point-of-use water heater right at the source, e.g., under a sink.
Therefore, when you turn on the faucet you have hot water instantly
available to you. This both eliminates your wait for the hot water
and saves water, our most valuable resource, from being wasted down
the drain as you wait for hot water to arrive.
Can I use point-of-use water heaters for applications other
than a sink?
Yes. You can place a mini storage tank (see Ariston) in-line with
your main water heater. These are available in 2.5-gallon, 4-gallon
and 6-gallon sizes. These provide you instant hot water at your
washing machine or dishwasher, for example, and by the time you
exhaust that supply, the main water heater that serves these
locations has caught up, so you have a continuous supply of hot
water.
Are your products difficult or expensive to install?
No, they are not difficult to install. The installation expense
depends on many factors. Although tankless water heaters are “on”
for only a small fraction of the day in most home uses, when hot
water is being called for they require a lot of energy because they
are heating water instantly. Because of this, AquaStar (gas tankless
water heaters) sometimes require expansion of the vent pipe and
PowerStar (electric tankless water heaters) sometimes require the
electrical service in the home to be upgraded.
Can any plumber install your products?
Yes, they should, after all it is just another appliance. But
experience has shown us that many will not because, as they say,
they are not familiar with the unit. To locate an installer in your
area please use the links below.
Mon-Fri 8-5pm (CT)
How
do they work?
