Water heater
timer
Electric hot water heater timers
A
hot water heater timer is worth considering. Timers are designed to
reduce heat loss and improve the efficiency of
an electric
powered water heating storage tank. The cost associated with reheating
stored domestic water when demand is either off peak or non existent
can be reduced with an electric timer.
Electric
powered tanks (including those in both heat pump water heating
systems and in solar powered systems) can benefit from the
addition of a timer.
There are several
things for would be consumers to consider;
Gas Powered
Storage Tanks and Timers
Many
industry professionals share the conventional wisdom
that timers are less effective when applied to gas
powered
storage tanks. In the
past, water heater timers were available for residential gas powered
storage tanks.
Most
models were mounted directly to the gas valve. The timer was designed
to
electro
mechanically close and open the gas valve. Many gas valves
fitted on the tanks were not designed for multiple daily
adjustments. In some cases gas leaks occurred due to the wear on
the valve seals.
Currently
(and in the foreseeable future) a hot water heater timer is not a
viable option for a residential gas powered storage tank.
Some
commercial gas powered storage tanks (as well as in apartment
buildings) often have electric controls connected to the valve. Others
have solenoid valves that electro mechanically control the gas valve.
In such
applications, gas water heaters can be fitted
with programmable timers. Consulting a local
water heating professional for installation is recommended.
Programmable
settings and heat loss
All conventional storage tanks experience standby
heat loss because the heating element is designed to maintain the
temperature of the stored domestic water. Maintaining a pre set
temperature is a cycling (on and off) task that repeats itself. In many
modern households this repetition can be both unnecessary and costly.
With a water heater timer the tanks' heating
element maintains a set temperature only at pre determined times of the
day.
Much like with programmable thermostats for home
heating and cooling systems, water heater timers are designed to take
advantage of the extended daily and/or weekly periods when demand is
either low or non existent.
Timers
and
Off Peak Electricity Rates
Check with
your local electricity provider and inquire about demand management
programs. Demand management programs are designed to deal with as well
as discourage high peak electricity use.
Providers
that have such programs offer whats referred to as "time of use"
rates where higher electricity rates are charged during on
peak hours and lower rates are charged during off peak hours.
Programming
or coordinating an electric hot water heater with a utilities off peak
rate can significantly increase the timers' overall effectiveness.
Significant
Savings With Timers?
With the addition of an electric water heater
timer the U.S Department of Energy estimates a 5% to 12% reduction on
water heating costs. The Illinois Institute of Technology has
estimated up to a 26% reduction on water heating costs.
Several factors will ultimately determine
the long term energy savings. The tanks' internal insulation or R-value
rating as well as whether or not additional external
insulation has been applied are very important factors.
The households' hot water consuming habits as well
as the ability or inability to take advantage of time of day
or off peak electricity rates can be more important in
determining long term energy savings.
In general, timers are more effective when
installed on less insulated (internally and externally) electric
powered storage tanks and when there coordinated with utility
off
peak electricity rates.
Types
of water heater timers
Water heater timers are available for both indoor
and outdoor applications. Some models are designed for installation
near the storage tank, other designs provide the additional flexibility
of mounting the timer relatively far away from the tank.
Different types of timers have different features
as well as varying programmable settings. It's important to note
that differences in features as well as settings may determine
which type (and even which model) is more suitable for your
home.
Box Timers
Box water heater timers are
classified by there appearance. These models have either digital
electrical control components or mechanical switch components in an
enclosed box. The box housing is usually made of plastic or
light
metal.
- Currently the most common type
of timer
available.
- Digital box timers generally have back up
batteries in the event of a power outage, while models with
mechanical switch controls do not.
- Models with mechanical switch controls use
approximate time settings and digital box models offer more accurate
programmable settings.
- Box timers are available for both indoor and
outdoor installation.
- Generally designed for mounting near the
storage tank.
- Are directly wired to storage tank and
generally have fairly easy to follow directions for installation.
- Compatible with a wide range of voltage; from
120 volts to 270 volts.
Digital
Programmable Timers
Digital timers offer more flexibility in the form
of additional programmable settings. These models are better
suited for households with varying consumption habits. The overall
flexibility of scheduling that is provided will ultimately depend on
the particular digital hot water heater timer.
- Quickly gaining popularity amongst energy
savings minded homeowners.
- Can allow for different settings for different
days of the week and weekend.
- Generally come with user friendly LED back
light control
screens as well as decorative mounting plates.
- Designed
for indoor installation and far removed from the
storage tank.
- These hot water heater timers are wall mounted,
generally near the AC and furnace thermostat for additional access and
home automation.
- Digital programmable timers are not wired
directly to the tank. Additional electrical wiring is required.
Consulting a local
water heating professional for installation is highly
recommended.
- Generally operate on 110 volts.
Countdown Timers
Countdown timers offer additional
flexibility in scheduling when compared to most box models as well, but
not when compared to programmable models. Countdown timers offer
intervals for on demand hot water use that
can be pre set. The timed intervals offered depend on the
particular model.
- Seldom utilized with storage tank water
heaters but quite compatible.
- Pre set intervals can
range from 10
minutes to 60 minutes. For example a user can set a 20 minute period to
activate the storage tank for machine washing. Some models have
mechanical dials and others have digital dials.
- Come with decorative mounting plates
much like programmable timers.
- Generally designed to be installed far away
from the storage tank.
- Much like with programmable models, there
designed
for wall mounting and installation near the home heating
and cooling thermostat if desired.
- Countdown timers are not wired directly to the
storage tank. Consulting with a local
water heating
professional for installation is recommended.
- Generally operate on 110 volts.
More on energy efficient water heating
Water heater maintenance and efficiency
- Water
Heater Maintenance; how to extend the life of an old or
recently purchased storage tank.
- Water
Heater Anode; periodically inspecting the sacrificial anode
rod is a maintenance procedure that protects the storage tank from
corrosion.
- Drain
Hot Water Heater; draining or flushing the storage tank
removes sediments that can compromise efficiency and volume.
- Water
Heater Drain Valve; inspect the drain valve on the tank for
potential leaks and drips.
- Water
Heater Expansion Tank; high water pressure can compromise any
storage tank. The addition of a hot water heater expansion tank can
both resolve and prevent high water pressure.
Energy efficient water heating options
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