Powerstar
Tankless Water
Heater
Review
of Bosch Powerstar AE3.4,
AE7.2, AE9.5, AE12 for point-of-use service
Powerstar water heaters are electric tankless appliances for
point-of-use service designed by German manufacturer Bosch. With four
models available these electric units can be installed and very
conveniently used for small hot water jobs.
Great
advantage of electric and on demand point-of-use units is the
elimination of a long pipe that runs from a distant
whole house water heater which reduces heat and
energy loss significantly.
Bosch Powerstar point-of-use
models are built to deliver an instant hot water to
one
specific plumbing application, like shower or kitchen sink, and
therefore the best location is
under the kitchen sink or bathroom. With such an
installation you don't have to wait 2-3 minutes to wash your dishes and
waste water; it is saving you time and money.
Note:
Point of use Bosch Powerstar water heaters are designed for indoor
installations
and in
the room where there is no chance of freezing. The only way to
fully protect your water heater is by removing it completely
from such exposure.
Model reviews
Bosch PowerStar water heaters for point of use service
are instantaneous
electric units with 99% thermal efficiency and with one goal, to supply
you with an endless
hot water at the spot and where demand is.
Based on the flow rate these small Bosch electric water
heaters provide and temperature
rise, there are 4 different models to choose from: AE3.4,
AE7.2, AE9.5 and AE12, where number shows the heating power output
(i.e. AE3.4 have heating elements of 3.4 kW).
Because of its compact and small design, they will
save you
valuable room space, with the option to install horizontally and
vertically,
virtually anywhere; in your home, small office,
store, both residential and commercial applications (model
AE12 installs horizontally only).
All these tankless models require 220/240 V except model AE3.5
that
requires
110/120 volts; and based on the model, required amperage is from 29 to
50
A.
Difference in amperage allows you to choose between low and high
temperature setting.
Example:
Powerstar AE 7.2 model has low setting of 3.05-3.6 KW with the 15 amps,
and its
high setting is from 6.1-7.2 kW with 30 amps. Model AE9.5 can go from
3.5 to 9.5 kW maximum heat output.
For Powerstar electric water heaters to function correctly,
water in
your home plumbing pipes has to be between 0.7 bar min (1.4
bar for AE12) to 10.3 bar max. (10 (20 for AE12)-150 psi).
Be
aware that your hot water outlet temperature doesn't depend on the
setting only, but the incoming water temperature as well, so your unit
might need temp. adjustments during the year (put on maximum during the
winter).
Temperature is factory set to 45 C or 113 F, and if you are
using Bosch
AE12
model use the Adjustment
Spindle to adjust to the desired temperature.
For other models AE3.5, AE7.2 and AE9.5 use the Power Selector Screw that
allows you to switch between low - LO and high - HI settings.
If you choose LO, only one heating element is operating and
the output
will be half power. Full power comes with both heating elements working
at the same time; you just have to set the screw on HI.
All models are equipped with a safety device called
thermal
cut-out, mounted on the heat exchanger. It cuts the power to heating
elements if the water flow is reduced too much and temperature
goes above allowed.
To reset the water heater back, so it can heat again, there is
a manual
reset button inside the unit.
Review
and consumer reports
Here is the summary of dozens of consumer
reviews collected
from different sources like Amazon,
Buzzillions, Home Depot and other online stores and customer review
sites.
Pros
-
Instant hot water, works quickly.
-
Easy to install.
-
Space saver and fits neatly in the kitchen
or bathroom cabinet.
-
Cheaper than traditional tank type water heater.
-
Solid copper heat exchanger has 5-year warranty.
-
If you
need any part replacement, you are covered for 1 year.
Cons
-
After unit has been used recently there is a short
burst of hot water unless run the water for a few seconds to settle
down the temperature.
-
No temperature setting button, have to use
screwdriver.
-
Technical support is slow, long phone-call holds.
-
Frequent quality issues even with brand new units.
-
The temperature may fluctuate because water pressure.
-
To reset the breaker you have to take the cover off.
-
Needs thermostat control.
To buy Powerstar electric tankless water
heater you have to
pay between
$190 and $269 for the brand new one and depending on the store,
or cheaper around $130 and up for factory refurbished unit.
(Pictures courtesy of Bosch)
