Takagi TKJr Water Heater Review
Takagi TKJr tankless water heater is the smallest gas model
for water heating from Takagi manufacturer, and is mainly designed for
light
residential applications. This article reviews its top features and
specification.
Takagi
TKJr as the smallest unit from Takagi, is only 20 inches tall,
and
is a good substitution for 40-gallon tank-type water heater, making it
ideal for
small homes, apartments, condos or offices, for both
residential
water heating and radiant heating applications. Another advantage is
its affordable
price.
Features and Specs
Power and efficiency
Takagi TKJr tankless water heater,
with its 140,000 Btu/hr provides
enough heating power for homes
with up to two bathrooms. TKJr models that are operating on natural gas
have the smaller energy efficiency (81%) than the
propane gas models (83%). Due to its high energy factor Takagi
Jr liquid
propane
model qualifies as an Energy Star unit.
On TKJr models that are using natural gas, heating
power can be
reduced to 19,500 and 17,500
Btu/hr for the propane gas units, all thanks to its design, which
allows
modulation on the gas valve.
Flow rate
If you live in the area with the ground water temperature of
close to
60 F, TKJr model can provide 3.8 gpm with the 60 F temperature rise.
Maximum flow through the TKJr water heater and its heat exchanger is
5.8 gpm. Takagi TKJr model doesn't provide an option to
increase the
hot water
production by using the Easy-Link system for
multiple configurations, such as the advanced models.
Temperature control
Recommended temperature of hot water is 120 F and Takagi Jr is
built to
provide four preset temperatures; from 113 to 183 F, but if
you want to have better control and more accurate temperature of hot
water,
then you should buy a TK-RE20 temperature controller.
Venting
Takagi TKJr model is power vented,
but you can also convert the unit to
work
as the direct vent with a sealed
combustion, for the installation in
the confined space, by using the optional TV09 conversion kit. Also,
depends on the installation viability and your preference, you can
mount
the Takagi TKJr indoor or outdoor (outdoor kit is needed).
Takagi TKJr uses 4" category III stainless steel vent to
extract the products of combustion, and it can be
installed vertical or horizontal. If used as direct
vent option, 3" air intake pipe diameter is recommended, made
of
PVC, ABS, galvanized steel and has to be sealed airtight. TKJr
model
is equipped
with the combustible air sensor designed to shut off the heater
if there is not enough air flow for the combustion.
Connections
All gas and water connections are designed as 3/4" NPT,
minimum water
flow to trigger the burner is 0.75 gpm.
Advanced features
Other important features are the electronic ignition with the
flame
sensor, self diagnostic system for troubleshooting and safety, and the
computer that monitors water temperature, water flow rate and gas flow
to ensure that you are getting the right amount of hot water at the
desired temperature.
Safety features
To protect the heating system and its users, Takagi TKJr water
heater
is equipped with several safety features including:
-
Built in freeze protection that contains several
ceramic heaters built into the unit. -
Manual reset Hi-limit switch that is set at 194 F.
-
Inlet and outlet thermistors to monitor the incoming
and outgoing
water temperature. -
Overheat cutoff fuse to protect the heat exchanger
from the excessive heat. -
Flame sensor to verify the ignition and that flames
are extinguished when the unit is OFF. -
Air/Fuel ratio rod.
-
Flue back-draft pressure switch.
-
GFI power supply connection.
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(Photo credit Takagi)
