Installation Manual and Owners Guide
































Flash Water Heater

Model T-K2
Suitable for potable water heating and space heating




FEATURING

ENDLESS HOT WATER
ON DEMAND
COMPACT, SPACE SAVING
ENERGY CONSERVING
COMPUTER CONTROLS
COMPUTERIZED SAFETY
NO PILOT LIGHT






































Takagi Industrial Co. USA Inc.
5 Whatney
Irvine, CA 92618
Toll Free (888) 882-5244 USA
Toll Free (877) 877-4935 CANADA
www.Takagi.com





- 2 -

CONTENTS

Specification .
2

Introduction ..3

For your safety
..3-4

Installation .
5
General
.
5
Accessories
.
5
Outdoor
Installation
.5-6
Indoor
Installation
.6-7
Venting
Instructions
..7
-9
Gas Supply/Gas Pipe sizing..10-11
Water Connection
. 11-12
Electrical Connection
. 12
Initial operation
. 13

Normal operation
. 13
Flow
.
13-14
Temperature setting
. 14
Freeze Protection Device . 14-15
Maintenance and Service ..15-16
Error
codes
..16

Wiring diagram
..17

For your Safety
..18

Danger ..19

Application ..20
Space
Heating
..20
Dual-purpose
heating ..21
Storage
Tank
..22
Re-Circulation
..22

Optional Items
..23

Component Diagram
24-26

Parts list
..27

Output temperature Chart
..28
SPECIFICATIONS

Natural Gas Input
Min. 20,000 Btu

Max. 185,000 Btu

LPG Input
Min. 19,000 Btu

Max. 175,000 Btu

Gas Connection
¾ NPT
Water Connections
¾ NPT

Water Pressure
Min. 15 psi

Max. 150 psi

Natural Gas Pressure Inlet
Min. 5 WC
Max.
10.5
WC

LP Gas Pressure Inlet
Min. 11 WC

Max. 14 WC

Manifold Pressure
Natural 2.3 WC

Propane 2.5 WC

Weight 60
lbs.
Dimensions 25x16.5x8.3
Ignition Electronic
Ignition
Electrical Supply
AC 120 V


*** NOTE ***

Check the rating plate to ensure this
product matches your specifications;

This appliance is certified for use at
altitudes from 0ft to 4500ft (1,370m) in
accordance to the latest CAN/CGA 2.17-
High Altitude Installation procedures at
normal manifold pressure 2.3"
W.C. (Natural Gas). Do not alter the orifice
jets or gas supply pressure. At altitudes of
4500ft to 5,000ft (1524m) lower the
manifold pressure to 2.1" W.C. (Natural
Gas). At 5000ft to 6000ft (1,829m), lower
the manifold pressure to 1.9" W.C. (Natural
Gas). For elevations above 6000ft or for
specific instructions on how to lower the
manifold pressure, please call the Takagi
office
Manufacturer reserves the right to discontinue, or change at any time, specifications or
designs without notice and without incurring obligations. - 3 -

INTRODUCTION

This manual provides information necessary
for the installation, operation, and maintenance
of the Model T-K2 water heater. This unit
includes a fan enabling sidewall (power)
venting and an advanced electronic ignition
system.
The model description is listed on the rating
plate which is attached to the front cover of the
water heater. Please read all installation
instructions completely before installing this
product. If you have any problems or
questions regarding this equipment, consult
with Takagi or its local representative.
Experiences have shown that most operating
problems are caused by improper installation.

The T-K2 Water Heater is an instantaneous,
tankless water heater designed to supply
endless hot water to your entire household
and/or commercial facility utilizing total
efficiency. The principle behind the T-K2 Water
Heater is simple. Once you open a hot water
tap, water flows through the T-K2 Water
heater. Once a minimum of 0.75 GPM is
achieved, the flow sensor automatically
commands the computer to turn on the fan,
activate the electronic igniter and open the gas
valves. The computer monitors water
temperature, water flow rate and gas flow to
ensure that you get the right amount of hot
water at the correct hot water temperature.
After the burners are ignited, the fire on lamp
is lit. The computer will modulate the gas
supply valve and water flow. 0.75 gallons per
minute is required to turn the burners on; after
the burners are ignited, the flow rate can be
lowered to 0.6 gallons per minute to maintain
the heater on. It is advisable to open further
the cold tap rather than decreasing the hot tap
to adjust the water temperature. As long as
you have water, gas and electricity, you will get
an endless flow of hot water. Open a hot water
tap to turn on your water heater. Close the tap
to turn off your water heater.
FOR YOUR SAFETY










PLEASE READ THIS MANUAL CAREFULLY
AND FOLLOW ALL DIRECTIONS.

1. Follow all local codes, or in the absence of
local codes, follow the most recent edition
of the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 in the USA or the
CAN/CSA B149.1 Natural Gas and
Propane Installation Code in Canada.
2. Properly ground the unit in accordance with
all local codes or in the absence of local
codes, with the National Electrical Codes,
ANSI/NFPA 70 in the USA or CSA
standard C22.1 Canada Electrical Code
Part 1 in Canada.
3. Carefully plan where you intend to install
your T-K2 Water Heater. Ensure that your
heater will have enough combustible air
and proper ventilation and locate your
heater where water leakage will not do
damage to surrounding areas. If there is a
possibility of water damage, install a
suitable drain pan under the unit which will
not restrict combustible airflow.
4.
Check the rating plate for the correct gas
type, gas pressure, water pressure and
electrical rating. If this unit does not match
your requirements, do not install.












The installer is responsible for the correct
installation of your Flash T-K2 Water
Heater. Installation and service must be
performed by a qualified installer (for
example, a licensed plumber or gas fitter)
otherwise the warranty by Takagi will be
void.
Rating plate - 4 -
5. If any problem should occur, turn off all hot
water taps and turn off the gas. Then call a
trained technician or the Gas Company or
the manufacturer.
6. WARNING: Do not disconnect the
electrical supply if the ambient temperature
will drop below freezing. The Freeze
Prevention Device only works if the unit
has electrical power. The Freeze
Prevention Device is rated for temperatures
down to 5 ºF (-15 ºC) in a wind free
environment. Refer to the section on
Winterizing and the Freeze Prevention
Device for more information. The Warranty
will not be covered if the heat exchanger is
damaged due to freezing.
7. WARNING: Water temperatures over
125ºF can cause severe burns instantly or
death from scalding. The water
temperature is set at 122ºF (50ºC) from the
factory to minimize any scalding risk.

Before bathing or showering always check
the water temperature.
8. WARNING: Do not use this appliance if
any part has been in contact with or been
immersed water. Immediately call a trained
technician to inspect and/or service the unit
if necessary.
9. WARNING: Do not store or use gasoline or
other flammables, vapors or liquids in the
vicinity of this appliance.
10. WARNING: Do not reverse the water
and/or gas connections as this will damage
the gas valves and can cause severe injury
or death. Following the diagram below
when installing your water heater:









GENERAL

The T-K2. Water Heater is an instantaneous,
tankless water heater designed to supply
endless hot water to your entire household
and/or commercial facility utilizing total
efficiency. The principle behind the T-K2 Water
Heater is simple. Once you open a hot water
tap, water flows through the T-K2 Water
heater. Once a minimum of 0.75 GPM is
achieved, the flow sensor automatically
commands the computer to turn on the fan,
activate the electronic igniter and open the gas
valves. The computer monitors water
temperature, water flow rate, and gas flow to
insure that you get the right amount of hot
water at the correct hot water temperature.
After the burners are ignited, the fire on lamp
is lit. The computer will modulate the gas
supply valve and water flow 0.75 gallons per
minute is required to turn the burners on;, after
the burners are ignited, the flow rate can be
lowered to 0.6 gallons per minute to maintain
the heater on. It is advisable to increase the
cold tap rather than decreasing the hot tap to
adjust the water temperature. As long as you
have water, gas and electricity, you will get an
endless flow of hot water. Open a hot water tap
to turn on your water heater. Close the tap to
turn off your water heater.



Thermist or

Fl ow
Sensor



- 5 -
INSTALLATION
GENERAL

All gas water heaters require careful and
correct installation to ensure safe and efficient
operation. This manual must be followed
exactly. Read the For Your Safety section at
the beginning of this manual.

1. The gas regulator is preset at the
factory; it is computer controlled and
should not need adjustment;
2. Maint