Aquastar Water Heater Review
Review of Bosch tankless
The Aquastar
water heater
is the Bosch trade name for the gas tankless water heaters and they are
the
most popular and reviewed (Amazon website) on demand gas
appliances with several models that are Energy Star
qualified.
Bosch in US offers several models that are designed for the
outdoor and
indoor installation, powered by
natural gas or propane, used as a solar
back-up, and built for smaller and larger homes.
These models include 2700ES, 2400ES, 2400E,
2400EO, 1600P, 1600H, 1600PS, 125BO, 125FX and 1000P
and they come with the thermal efficiency from
80% to 87%, which qualifies, some models from Aquastar
water heater series, Energy Star compliant.
Features and Benefits
The
following features and safety devices are standard on the majority of Bosch
water heaters including the most popular Aquastar
and
2700ES 2400ES models.
There are also models that are not equipped with such
features; they have a slightly different features and
less high-tech and sophisticate elements.
-
Every Bosch Aquastar water heater is
suitable for potable
water heating;
bath and kitchen, and cannot be used for space
heating.
-
As the burner
output is proportionate to hot water flow demand, the power is
usually
controlled by modulation on the gas valve that further
controls the constant gas/air
ratio; or manually with a gas control slide button (like Aquastar
125BO
or 1000P
models).
-
Bosch Aquastar
water heater supports variable flow applications, with
modulating water valve or adjustable water flow restrictor (like 125BO
models), for improved comfort and temperature control. Minimum water
pressure is needed so the unit can be activated.
- Key/Touch Pad interface control.
- High quality copper heat exchanger provides
a longer working life and it comes with 12 year warranty.
- High efficiency Ceramat Burner.
- Real-time diagnostics for troubleshooting.
- Failure codes for easy diagnostics and repair.
- Reset button.
- Bosch Aquastar tankless water heaters
are water
resistant.
- Built-in freeze protection, electrical power must be
provided.
- Natural gas and Propane, LP.
- Aquastar tankless hot water heater is
not
intended for RV's, boats, mobile home or
manufactured homes.
- Not intended as a solar backup (read below for
eligible models).
- Aquastar tankless models 1600PS
and 125BS can be used as the preheated water backup and bring
the
efficiency
to your solar water heating system or woodstove. Before the
installation, check the local codes to determine if you need a
tempering
valve.
Accessories
review
- Optional wireless remote control
- Cascading kit - TLINK
- Gas conversion kit (i.e. when converting from natural
to LP gas)
- Vertical and horizontal vent kit and stainless steel
bird screen
Safety
devices
- Flame failure device (ionization flame rod sensor)
- Safety thermocouple and piezo lighter for pilot light
models
- Pressure relief valve (included)
- Temperature limiter - as the overheat prevention
- Inlet and outlet temperature sensor
- Fan speed monitoring (where applicable)
- Backflow temperature sensor
- Wireless remote for quick and easy temperature
control. (TSTAT2)
Model Types Review
The major differences between Aquastar
tankless water
heaters, which are also the key
factor when planning to buy, are:
- Hot water capacity
- Venting installation
- Ignition type
- Efficiency
Selecting Aquastar based on the water capacity
How
to properly size your tankless
water heater?
The easiest method when choosing a water
heater is to know how many plumbing applications; showers,
dishwasher, washing machine and kitchen sink will use hot water. Based
on that or your family size, you can decide about the capacity.
-
Aquastar
2700
series can provide enough hot
water for up to three
plumbing units simultaneously, delivering over 7 gallons per minute. -
Bosch
Aquastar 2400
models can be used for two major hot water applications at the
time, providing around 6 gallons per minute. -
Aquastar 1600, 125BO and 125FX models
are
good enough for one bathroom
homes, providing around 4.3 gallons per minute,
while 1000P
is used for cottages and camp houses, delivering 2.6 gallons per minute.
Note:
The suggestion is to use inlet and outlet pipes no less than 3/4"
or 19.05 mm, so they can supply enough water for the full water heater
capacity use.
Selecting Aquastar based on the ignition type
- Bosch Aquastar water heater 1600H
uses a hydro-generated ignition which makes the unit
electrically-independent. A small
turbine wheel is installed
inside the unit and attached to an electromagnetic wire. When you open
a hot water tap, the flow of the water spins the turbine wheel, which
spins two dissimilar magnets that in turn sends a 1.5 volt DC current
through the wire, and provides the spark to ignite the gas burners.
- Bosch produces Aquastar models with
the pilot light
and piezo
igniter: 1600PS, 1600P,
1000P, 125BS, 125BO and electronic pilot ignition 125FX model.
- Electronic
ignition electrode with the 120V plug-in
supply is used for the next Aquastar models:
2700ES,
2400ES, 2400EO, 2400E.
When the burner does not ignite
and when the hot water is on, the electrode might be one of the causes
for the problem. The electrode might not produce the spark or one of
the electrodes,
called the flame sensor, doesn't detect the flame ionization.
Venting options
Room sealed combustion models
If
your home requires direct venting option, the following Aquastar
models are available; 2400ES and 2400E, and they come with a
room-sealed combustion chamber and built-in power vent.
These models can be installed in the bathrooms,
kitchen, even bedrooms, as they are
indoor and room sealed, but only if using a twin pipe solution;
one pipe for venting gases out and the other for fresh air intake.
If it is one pipe solution than ventilation
has to be provided as the inside air is used for
combustion. For these unsealed units there should be a dedicated room
with proper
venting.
Aquastar water heater 2700ES
and 2400ES
are equipped with a primary fan, mixer, and secondary fan, for better
water heater performance and efficiency.
Another advantage is that they have the option to be installed
outdoor,
using the right vent kit (AQOK) but for the approved climate,
while 2400E can be installed indoor only.
With their built-in
power vent capability, you will have an option for easier installation
as they are designed for vertical and horizontal vent termination.
Direct Vent / Power vent
Aquastar water heater 125FX
is using power vent
(exhaust fan) and is designed for horizontal venting
only. 125BS, if using power vent kit can use a sidewall vent. With
1600PS,
1600P and 1600H sidewall termination is available as long as the unit
uses the appropriate power vent kit.
1600P, 1600H, 1600PS and 125BS are
models that can function as direct vent models also with a
vertical termination using natural draft, while 1000P has to be used
as a direct vent and vertical termination using natural draft.
Outdoor models
For the outdoor
installation, there are two models from Aquastar
water heater series
available: 2400EO
and 125BO
with the great advantage; eliminating the need for a costly venting
kit, freeing up the space in your home and reducing the
problem
and worry significantly of the potential gas and water leak.
Note:
For freeze protection, electrical supply has to be provided and to plug
in 120 V outlets.
The
anti freeze kit is designed to provide protection for water heater, down
to 5 F, but the suggestion is to drain the unit if exposed to long term
freezing conditions.
High Efficiency models
Models Aquastar
2700ES and Aquastar
2400ES are the only two Bosch
models
that are
EnergyStar awarded and high efficient gas tankless water heaters.
What
makes these Aquastar water heater models high
efficient (where EF
factor is 0.82 or higher) is their efficient gas burning with high
power pre-mix compact burner and the help it is getting from primary
and secondary fans.
(Pictures courtesy of Bosch)
