Takagi T - M1 User manual

MOBIUS Water HeaterTakagi Industrial Co. USA, Inc.
Store these instructions next to the hot water heater for reference purposes.
TAKAGI INDUSTRIAL CO. USA Inc.
6 Goddard, Irvine, CA 92618
Tel. (949) 453 - 8388, FAX. [phone]
http://www.takagi-usa.com
Installation and Operating Instructions
MOBIUS WATER HEATER
MODEL T - M1
Instantaneous Tankless Gas Water Heater
Suitable for
Potable water heating and Space heating
Indoor and Outdoor installation
FEATURES
θENDLESS HOT WATER SUPPLY
θON-DEMAND
θPILOT LESS SYSTEM
θCOMPACT, SAVE SPACE
θCOMPUTER CONTROL
θCOMPUTERIZED SAFTY
θCONSERVES ENERGY
θFULL CAPABILITY FOR MANIFOLD

1
FOR YOUR SAFETY - READ BEFORE OPERATING
Thank you for purchasing this water heater. Properly installed and maintained,
it should give you years of trouble free service. Read this installation manual
before system install to application whether with or without experience with
Takagi Tankless Gas water heather.
Do not copy this installation manual without consent from Takagi
Industrial Co. USA Inc. Copy Right 2002, Takagi Industrial Co. USA Inc.
FOR YOUR SAFETY - This product must
be installed and serviced by a professional
service trained technician. Improper
installation and/or operation could create
carbon monoxide gas and flue gases, which
could cause serious injury or death. Improper
installation and/or operation will void the
warranty.
WARNING: If the information in this
manual is not followed exactly, a fire or
explosion may result, causing property
damage, personal injury or death.
•Do not store or use gasoline or other
flammables, vapors and liquids in the
vicinity of this or any other appliance.
•WHAT TO DO IF YOU SMELL GAS
•Do not try light any appliance.
•Do not touch any electrical switch,
also do not use any phone in your
building.
•Immediately call your gas supplier
from a neighbor’s phone. Follow the
gas supplier’s instructions.
•If you cannot reach your gas
supplier, call the fire department.
•Only a Licensed contractor or plumber,
trained technician, certified installer and
service agency should perform installation
and/or service this unit otherwise warranty
will void from manufacture.
WARNING: To install this unit correctly, you
must follow the procedures listed in this
manual. Failure to do so will void any and all
warranties offered by Takagi Industrial Co.
USA, Inc.
Do not make any changes to the water
heater, or to its gas controls, gas orifices,
wiring or draft. Any modifications may void
the warranty. If the unit must be modified
because of special conditions or
circumstances, consult the manufacture or
factory representative before making any
changes.

1
CONTENTS
For Your Safety …………. 4
Operation …………. 5
•General …………. 5
•Temperature …………. 5
•Freeze Prevent Device …………. 6
•Winterizing …………. 6
Installation …………. 7
•General …………. 7
•Accessories …………. 8
•Optional Items …………. 8
•Outdoor Installation .………… 8
•Indoor Installation …………. 9
•Combustion Air Supply …………..9
•Venting Instructions …………..10
•Gas Supply …………. 12
•Water Connection …………. 13
•Pressure Relief Valve …………. 14
•Electrical Connection …………. 14
Starting Operation …………. 15
Operating Instruction …………..15
Wiring Diagram …………..17
For your Safety …………..18
Application …………..20
•Space Heating …………..20
•Dual-purpose heating …………..21
•Storage Tank …………..22
•Re-Circulation …………..22
Temperature Setting …………..23
Manifold Multi System …………..23
Maintenance and Service …………. 27
Error codes ……...28, 32
Trouble Shooting …………. 29
Component Diagram …………..33
Part List …………. 37
Output temperature Chart …………..39
SPECIFICATIONS
Natural Gas Input Min. 25,000 Btu
Max. 235,000 Btu
LPG Input Min. 25,000 Btu
Max. 225,000 Btu
Gas Connection ¾” NPT
Water Connection 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 2.2” WC
Propane 2.7” WC
Weight 70 lbs.
Dimensions 24.5”x16.5”x8.3”
Ignition Electronic Ignition
Electrical Supply AC 120 V
***
•Inlet gas pressure must not exceed the
above maximum values.
•For gas pressures lower than 5” WC for
natural gas and 11”WC for propane, call
the manufacturer.
•Before installing in areas over 4,500 feet
above sea level, contact the manufacturer
for high altitude adjustment instructions.
•Check the rating plate to insure this product
matches your specifications.
•Takagi - USA is constantly improving our
products; therefore specifications are
subject to change without prior notice.

INTRODUCTION
This manual provides information necessary
for the installation, operation, and maintenance
of the MOBIUS Model T-M1 water heater. This
unit includes a power fan for power venting
system, and an advanced electronic ignition
system.
The model designation is listed on the rating
plate, which is attached to the front of the
water heater. Please read all application and
installation procedures completely before doing
the installation. If you have any problems or
questions regarding this equipment, consult
the Takagi Industrial Co. USA, Inc. or local
factory representative. Experiences have
shown that most operating problems are
caused by improper installation (human error).
FOR YOUR SAFETY
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 USA or the CGA
standard, CAN/CGA B149.1 or .2
Installation Codes for Gas Burning
Appliances 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 MOBIUS Water Heater. Insure that
your heater will have enough combustible
air, 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.
5. If any problem should occur, turn off all hot
water taps and turn off the gas. Then call a
trained technician or Gas Company or
manufacturer.
6. WARNING: Do not disconnect the
electrical supply if the ambient
temperatures will be reaching freezing. The
Freeze Prevention Device only works if the
unit has proper electrical power. The
Freeze Prevention Device is rated for
temperatures down to 5ºF (-15ºC) in a wind
free environment. The wind chill factor will
cause the MOBIUS Water Heater to freeze
and be damaged at temperatures below
5ºF (-15ºC). Refer to the section on
Winterizing and Freeze Prevention Device
for more information. Warranty will not be
covered if the heat exchanger is damaged
by weather. Please read winterize section
in this installation book.
7. WARNING: Before bathing or showering
always check the water temperature. Do
not leave children or infirm person
unsupervised in the shower or bath. The
water temperature is set at 140ºF (60ºC)
from the factory to maximize the amount of
hot water you can use without an optional
temperature remote controller, Water
temperature over 125ºF can cause severe
burns instantly or death from scalding.
8. WARNING: Do not use this appliance if
any part has been contacted or been
immersed water. Immediately call a
certified, trained technician or manufacture
to inspect and/or service the unit if
necessary.
9. WARNING: Do not store or use gasoline or
other flammables, vapors and liquids in the
vicinity of this or any other appliance.
10. WARNING: Do not reverse the water
and/or gas connections, this will damage
the heat exchanger and can cause severe
injury or death from scalds. Following the
diagram below when installing your
MOBIUS water heater.

RATING PLATE
Pressure relief Valve
HOT COLD GAS
GENERAL
The MOBIUS Water Heater is an
instantaneous, tankless water heater designed
to supply endless hot water to your entire
household and/or commercial hot water needs
utilizing total efficiency. The principle behind
the MOBIUS Water Heater is simple. Once you
open a hot water tap, water flows through the
MOBIUS Water heater. Once a minimum of
0.75 GPM is achieved the flow sensor
automatically commands the computer to
electronically turn on the fan, activate the
electronic igniter and open the gas valve the
computer monitors the water temperature,
water flow rate, and gas flow the insure you get
the right amount of hot water with the correct
hot water temperature. After the burners are
ignited the “fire on” lamp is lit. Computer will
modulate gas supply to 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 and still keep the heater on.
It is advisable to increase the cold tap rather
than decreasing the hot tap to adjust the water
temperature. Now 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.
Temperature
The temperature has been set at the factory
Max. of 140º F (60º C). The computer will
electronically control this temperature. Mix the
cold water with hot to get the water
temperature you desire. If desiring hot water
temperature want other than factory setting
temperature (140ºF), please purchase the
optional temperature remote controller, part No.
TM-RE10. With this optional part TM-RE10 you
can set the temperature from 95 º F to 176 º F,
please carefully read the instructions prior to
installation, failure to do so can damage the
temperature controller and/or the water heaters
onboard computer, which will void warranty.
WARNING: Temperatures above 125º F (52º
C) can cause severe burns or death from
scalding. Children, disabled and the elderly are
at high risk of being injured. Feel the water
temperature before bathing or showering. Do
not leave children, disabled and the elderly
without supervision. MOBIUS water heater will
produce hot water based on setting
temperature. Please refer to the temperature
and gallons per minute chart on the back of
this manual for your convenience.

Freeze Prevention Devices
This unit comes equipped with heater blocks to
prevent freezing which can damage the heat
exchanger. For this freeze prevention system
to operate there has to be electrical power to
the unit. Damage to the heat exchanger
caused by freezing due to electric power
outage is not covered under warranty.
The freeze prevention devices will not work
if the electrical power source is
disconnected.
The unit has been rated for temperatures down
to 5º F (-15º C) in a wind free environment.
The wind chill factor will cause the unit to
freeze at temperatures above 5º F (-15º C).
Do not install the water heater in an area with
extremely cold weather, this will void warranty
and Takagi-USA will not be held responsible
for any damage occurring from such
environment. For this purpose a back flow
prevention kit (Part TK-TV03) is highly
recommended for areas with freezing weather,
to prevent freezing air from entering through
the exhaust venting when the water heater is
on standby which can damage the heat
exchanger.
CAUTION: The pipe heaters are located on
the MOBIUS Water Heater only. Any hot or
cold water pipes located outside of the unit will
not be protected. Properly protect and insulate
these pipes from freezing.
Winterizing
If you will not be using your heater for a long
period of time or if the temperatures will drop
below 5º F (-15º C) with the wind chill factor,
turn off your heater and drain the unit of water.
This will keep your unit from freezing and being
damaged. Follow these instructions carefully:
1. Turn off the power supply to the Flash
Water Heater.
2. Turn off the manual gas control valve
located outside your heater.
3. Turn off the manual water shut off valve
located on the water supply line.

4. Open all hot water taps in the house.
(Bathroom, kitchen, laundry room, etc.).
When the water flow has ceased, close all
hot water taps.
5. Have a bucket or pan to catch the water
from the units drain plugs. Remove the
drain plugs to drain all the water out of the
unit.
6. Wait a few minutes to ensure all water
have drained from unit.
7. At this time please check the water filter
located inside the cold inlet. With a tiny
brush, clean the water filter of any calcium
or debris which may have accumulated
over time and reinsert the filter back into
the cold water inlet.
8. Securely screw the drain plugs back into
place.
Now when you want to use your heater
again follow these steps:
Make sure all hot water taps are closed and
the drain plugs are securely attached.
1. Purge the water line of debris.
2. Turn on the manual water control valve
located on the water supply line.
3. Open all the hot water taps to verify water
flows to the taps. Then close hot water taps.
4. Turn on the manual gas control valve
located on the gas supply line.
5. Turn on the power supply to the MOBIUS
Water Heater.
INSTALLATION
General
All gas water heaters require careful and
correct installation to insure safe and efficient
operation. This manual must be followed
exactly. Read the “For Your Safety” section in
the beginning of this manual.
1. The regulator is preset at the factory,
this is computer controlled and should
not need adjustment.
2. Maintain proper space for servicing.
Install the unit so that it can be
connected or removed easily.
3. The electrical connection requires a
means for switching off the power
supply.
4. Avoid installing the unit in an area with
high level of dust, sand, debris such as
flower within a bakery shop which can
become airborne can enter and buildup
within the fan causing damage to the
fan and/or burner. So please take
precaution to prevent such foreign
matter from entering the unit.
5. Impure particles from these objects
may clog the air vent or reduce
functions of the rotating fan and cause
gas not to burn properly. Regular
maintenance is recommended for these
types of environment.
6. Do not install the unit where the
exhaust vent is pointing into any
opening in a building or where the
noise may disturb your neighbors.
Make sure the vent termination is 4’
feet from a doorway or opening to
prevent exhaust from entering.
Drain Drain and Filter
This section is for the installer. The installer
is responsible for the correct installation of
your MOBIUS Water Heater.
For Your Safety: Only a certified and
trained service technician or qualified
plumber may service or install your product.

Accessories
Check that all parts listed below were included
with the unit.
Installation Manual, Warranty Card and
Optional Part Information
Optional Items
1. TM-RE10 Temperature Remote Controller
The TM-RE10 Temperature Remote Controller
has two functions, it allows the output
temperature from the T-M1 to be adjusted
within the range of 95 °F to 167 °F, and it also
works as a diagnostic tool that will give a
concise error code whenever there is a
problem with the unit. The temperature options
are 95°F, 100°F, 102°F, 104°F, 106°F, 108°F,
109°F, 111°F, 113°F, 115°F, 117°F, 122°F,
131°F, 140°F, 158°F, 167°F, and 176°F for
180°F. See the trouble shooting section for
information on possible error codes.
2. TK-TV01 Vent Terminator
This terminator can be used where a T-M1 is
going to be vented out through a wall. This is a
CSA approved part of the unit. Connect a
Category III Stainless vent pipe from the top of
the unit to the backside of this terminator to
exhaust flue gases through the wall without a
thimble. Install vent terminator in accordance
with manufacturer’s installation instructions
and any applicable local codes.
3. TK-TV03 Vent Damper
The TK-TV03 Vent Damper prevents the
backflow of air through the exhaust vent. This
is CSA approved part of the unit. This helps
prevent harmful exhaust gases from entering
the home, as well as helping to prevent the
units from freezing in areas where cold air can
be blown into the exhaust system. Install vent
damper according to manufacturer’s
installation instruction, and any applicable
codes.
4. TM-TV06 Vent Cap
The TM-TV06 Vent Cap is for outdoor
installation with the T-M1 water heater. The
cap is installed on the top of the unit, instead of
connecting an exhaust vent. The cap will
prevent any debris that might be in the
environment from entering the unit and causing
damage or a fire hazard, as well as preventing
rain or other weather from entering the unit.
OUTDOORS INSTALLATION
Follow all local codes and in the absence of
local codes, follow the National Fuel Gas Code
ANSI Z221.23 in USA or in Canada CAN/CGA
B149.1 or .2 Installation of Gas Burning
Appliances.
Locate the water heater in an open, unroofed
area, and maintain the following minimum
clearances. MOBIUS water heater is wall
hanging installation only.
Piping side (Bottom) 12”
Front (Maintenance
space) 24”
Back of heater 1”
Top of heater 36”

Do not install this water heater under an
overhang, less than 3 feet from its top or eaves.
The area under an overhang must be open to
three sides
WARNING: Do not have the vent terminal
pointing toward any opening into a building. Do
not locate your heater in a pit or location where
gas and water can accumulate.
WARNING: Do not install the heater where
water, debris, or flammable vapors may get
into the flue terminal. This may cause damage
to the heater. Warranty will void.
WARNING: In the USA, do not install the water
heater vent terminator within 4 feet of any air
intake opening into a building. In Canada do
not install the water heater vent terminator
within 10 feet of any air intake opening into a
building.
WARNING: Improper installation can cause
nausea or asphyxiation from carbon monoxide
and flue gases which could result in severe
injury or death. Improper installation will void
product warranty. For high altitude installation
above 4,500 feet, Contact the manufacturer on
how to handle this situation.
INDOOR INSTALLATION
Combustion Air Supply
The water heater location must provide enough
air for proper combustion and ventilation of the
surrounding area. See the latest edition of
ANSI Standard Z223.1 or any your local codes
that should be applicable. In general these
requirements specify that if the unit is installed
in a confined space, there must be permanent
air supply opening.
Minimum recommended Air supply to water
heater
Water
heater size Outside air area Inside air area
Max.
235.000
BTU
59 Sq. IN 235 Sq. IN

Air Supply from Outside Building
When combustion air supplied directly through
an outside wall, such as intake louvers
openings into the dwelling, opening should
give a minimum free area of one square inch
per 4000 BTUH inputs of the total input rating
of all appliances in the enclosed area.
Air Supply from Inside Building
When combustion air is supplied from inside
the building, each opening of the closet door
should have a minimum free area of one
square inch per 1000 BTUH input of the total
input rating of all appliance in the enclosed
area. These openings should never be less
than 100 Sq. in.
Combustion Air Supply from Make up air
Fan.
MOBIUS water heater is equipped with a
combustible air sensor that will shut off the
MOBIUS when inadequate combustible air
supply to unit is detected, MOBIUS water
heater will stop until it has enough combustible
air.
Any equipment, which exhausts air from the
room around the unit, can deplete the
combustion air supply. Such equipment can
also reverse the action of the venting system.
This could cause flue products to accumulate
in the space where the water heater is installed.
Additionally air must be supplied to
compensate for any exhaust effect.
If a fan blower is used to supply air to the water
heater or utility room, the installer should make
sure it does not create drafts, which could
cause nuisance shutdowns. If a blower is
necessary to provide adequate combustion air
to the water heater, a switch or equivalent
devices must be wired into the water heater
control circuit or proper devices to prevent the
water heater from firing unless the blower is
operating.
Venting Instructions
GENERAL
WARNING: Improper venting of this appliance
can result in excessive levels of Carbon
Monoxide, which can result in severe personal
injury or death.
This water heater must be vented in
accordance with "Section Venting of
Equipment", of the latest edition of the National
Fuel Gas Code, ANSI Z223.1 and all
applicable local building codes. In Canada,
follow CAN/CGA installation codes.
general rules for venting the MOBIUS water
heater.
1. Place the water heater as close as
possible to the vent.
2. The vent collar on the water heater
must be fastened directly to an
unobstructed vent pipe.
3. Do not weld the vent pipe to the water
heater collar. The weight of the stack
must not rest on the water heater. The
top of the water heater must be easily
removable for normal service and
inspection of the unit.
4. The water heater vent must not be
connected to a fireplace, wood stove or
other equipment.
5. Avoid terminating the water heater vent
near any air-conditioning or air-supply
fans. These fans can pick up the
exhaust flue products from the water
heater and return them to the building.
This can create a health hazard.
6. Avoid using an oversized vent pipe or
using extremely long runs of the pipe.
This may cause excessive cooling and
condensation of flue gases resulting in
damage to the heat exchanger and are
not covered under warranty.
Exhaust Vent
This water heater must be vented in
accordance with the section on venting of
equipment in the latest edition of the National
Fuel Gas Code.
This is a Category III appliance, and must be
vented accordingly. The vent system must be
gas tight. All seams and joints must be sealed
with silicone sealant or preferably high heat
resistant, UL listed aluminum adhesive tape
having a minimum temperature rating of 350º F.
For best results, a horizontal vent system
should be as short and straight as possible
with Single wall Stainless steel vent pipe or

other approved, noncombustible, corrosion-
resistant material. The following are UL listed
manufacturers: ProTech Systems, FasNSeal,
Z-Flex Inc. Z-Vent II and Heat-Fab Inc. Saf-T
Vent. This unit requires 4” vent pipe. Connect
the vent pipe to the unit so that it is sealed
airtight. Follow the vent pipe manufacturer’s
instructions when installing the vent pipe. Do
not common vent this appliance with any other
vented appliance. The venting system must not
exceed a length of 35 ft. minus 5 ft. for every
elbow. Do not use more than 3 elbows.
When installing the vent system, all applicable
national and local codes must be followed. If
you install thimbles, fire stops or other
protective devices, and they penetrate any
combustible or noncombustible construction,
be sure to follow all applicable national and
local codes.
Fan assisted appliances should follow the
requirement as indicated in the latest edition of
ANSI Z233.1/NFPA 54.
The entire vent system must not exceed the
size specified in table below.
Diam
eter Max. No. of
Elbow
Max. Vertical or
Horizontal run in
Length
4” 3 Ea. 35 ft
For each elbow added, deduct 5 ft. from
max. Vent length.
No. of Elbows Max. Vertical or
Horizontal Length
0 35 ft.
1 30 ft.
2 25 ft.
3 20 ft.
When the horizontal vent run exceeds 5 ft. the
following criteria must be observed;
•Attach a vertical pipe at least 2” high to the
water heater outlet before the horizontal
run.
•Support the vent run at 3 ft intervals with
overhead hanger.
•Pitch up the vent run toward the vent
terminal at a rate of 1/ 4” per foot.
Indoor installation clearance.
Piping side (Bottom of water
heater) Min. 12”
Front (Maintenance space) Max. 24”
Min. 4”
Back of heater 1”
Non piping sides (Side of
water heater) Min. 1”
Top of heater 12"
Vent Termination
A sidewall vent terminal must be used when
the water heater is vented through a sidewall.
Manufacture's recommend to use Takagi -
USA parts No.TK-TV01 as a vent terminator.
The vent terminal provides a means of
installing vent pipe through the building wall
and must be located in accordance with ANSI
Z223.1/NFPA 54, or in Canada CAN/CGA-
B149 and local applicable codes.
Locate the vent terminal so that it cannot be
blocked by snow. Most codes require that
termination be at least 12 inches above grade,
but the installer may determine if it should be
higher depending on job site condition and
applicable city code.

1
Installation vent terminator Clearance
Gas Supply and Gas Piping Sizing
This unit needs a manual gas control valve
(System Shutoff Valve) that must be placed on
the unit before it is connected to the gas line.
Check the gas inlet pressure and the type of
gas matches the rating plate located on your
water heater. Insufficient gas pressure and
volume will cause your MOBIUS Water Heater
to be inefficient performance and not work
properly. Sizing of gas piping system correctly
following ANSI233.1/NFPA 54, or by local code.
The minimum and maximum inlet gas
pressures are listed below
Natural Gas Min. 5” WC
Max. 10.5” WC
Propane Gas Min. 11” WC
Max. 14” WC
When measuring the inlet supply pressure, the
water heater and all other gas appliances
sharing the water heater gas supply line must
be firing at maximum capacity. Maximum gas
pressures must not exceed this value. Low gas
pressure could be caused by an undersized
gas pipe, this will cause the MOBIUS water
heater’s performance to diminish and unable to
reach maximum performance.
When connections are completed, check for
gas leaks by applying soapy water to all gas
fittings and connections. Soap bubbles are a
sign of gas leaks.
This appliance and its individual shut-off valve
must be isolated from the gas supply piping
system by unplugging the unit and turning off
the main gas valve during any pressure testing
of the gas supply piping system at test
pressures equal to or less than ½ Psi. The
appliance and its gas connections must be
leak tested before placing the unit in operation.
Always use approved connectors to connect
the unit to the gas line. Always purge the gas
line of any debris before connecting to the
heater gas inlet.
WARNING: Conversion of this unit from
natural gas to propane or propane to natural
gas cannot be done in the field. Contact your
local retailer or distributor to get the correct unit
for your gas type. Conversion done by anyone
other the manufacture will void any and all
warranty.

Recommend Gas pipe size for
MOBIUS Water Heater
Distance from Gas Meter Pipe Size (inches)
0' - 20' 3/4"
20' - 80' 1"
80' - 300 1-1/4"
NOTE: These Tables are for Natural Gas (0.60
Specific Gravity) and based on Pressure Drop
of 0.5 Inch water columns. This table is Gas
piping supply straight to the water heater
without any tab to other gas appliance.
Natural Gas Supply Piping
Based on 0.60 specific gravity for natural gas at .5” WC pressure drop
DOE standard is 1100 BTU per cubic ft. of natural gas
Pipe
Size Cubic Feet of Natural Gas
Length 10’ 20’ 30’ 40’ 50’ 60’ 70’ 80’ 90’ 100’ 125’ 150’ 200’
½” 174 119 96 82 73 66 61 56 53 50 44 40 34
¾” 363 249 200 171 152 138 127 118 111 104 93 84 72
1” 684 470 377 323 286 259 239 222 208 197 174 158 135
1 ¼” 1404 965 775 663 588 532 490 456 428 404 358 324 278
1 ½” 2103 1445 1161 993 880 798 734 683 641 605 536 486 416
2” 4050 2784 2235 1913 1696 1536 1413 1315 1234 1165 1033 936 801
Propane Supply Piping
Based on 11” WC supply pressure
Pipe
Size kBTU of Propane
Length 10’ 20’ 30’ 40’ 50’ 60’ 70’ 80’ 90’ 100’ 125’ 150’ 200’
½” 275 189 152 129 114 103 96 89 83 78 69 63 55
¾” 567 393 315 267 237 217 196 185 173 162 146 132 112
1” 1071 732 590 504 448 409 378 346 322 307 275 252 213
1 ¼” 2205 1496 1212 1039 913 834 771 724 677 630 567 511 440
1 ½” 3307 2299 1858 1559 1417 1275 1181 1086 1023 976 866 787 675
2” 6221 4331 3465 2992 2646 2394 2205 2047 1921 1811 1606 1496 1260
Water Connections
An approved manual water control valve (water
shutoff valve) must be placed on the cold water
supply line. All soldering materials and piping
materials must be suitable with potable water.
If the water heater is installed in a closed water
system, such as one having a backflow
preventer in the cold water supply line, must be
provided to control thermal expansion. Contact
the water supplier or local plumbing inspector
on how to control this situation.
After installation of water heater is complete,
purge the water line to remove all the debris
and air from the line. Failure to or not doing so
may cause damage to the heater. There is a
wire mesh filter to trap debris from entering
your heater. This will need to be cleaned
periodically for long life expectance.

Pressure relief Valve
HOT COLD GAS
WARNING: Be careful not to reverse the hot
outlet and cold supply line connections to the
MOBIUS Water Heater. This will cause your
heater to operate dangerously and void
warranty. Make sure the hot and cold lines are
connected properly. Refer to the FOR YOUR
SAFETY section at the front of this manual.
PRESSURE RELIEF VALVE
The Mobius has a built Hi-Limit (high-
temperature) shut off switch and no store hot
water therefore only a “pressure only” relief
valve is required.
This unit does not come with an approved
pressure relief valve. An approved pressure
relief valve must be installed on the hot water
outlet. A “Tee” fitting should be used to attach
the pressure relief valve. Then place the
pressure relief valve 6” inches from water flow
as shown in picture to prevent premature wear
of relief valve. The pressure relief valve must
meet and followed local code.
The discharge capacity must be at least
235,000 Btu/hr. The discharge piping for the
pressure relief valve must be directed so that
the hot water cannot splash on anyone or
nearby equipment. Attach the run-off tube to
the pressure relief valve, and run the end of
the tube to within 6" from the floor. Do not
install any reducing couplings, valves or any
other type of restriction in this line. This run-off
tube must be installed to allow free and
complete drainage of both the valve and the
run-off tube.
If the pressure relief valve on the appliance
discharges periodically, this may be due to the
thermal expansion in a closed water supply
system or defective pressure relief valve,
replace a new pressure relief valve. Contact
the water supplier or local plumbing inspector
on how to correct this situation.
The pressure relief valve must be manually
operated once a year to check for correct
operation.
Should overheating occur or gas supply fail to
shut off, turn off the manual gas control valve
to the appliance.
Pressure Valve
CAUTION: Only the pipes within the heater are
protected on the MOBIUS Water Heater. Any
hot or cold water pipes located outside of the
unit will not be protected. Properly protect and
insulate these pipes from freezing.
Electrical Connections
WARNING: The heater must be electrically
grounded. Follow the requirements of the local
authority having jurisdiction. In the absence of
such requirements, follow the latest edition of
the National Electrical Code ANSI/NFPA 70 in
the U.S., or the latest edition of CSA C22.1
Canadian Electrical Code, Part 1, in Canada.
Do not rely on the gas or water piping to
ground the metal parts of the water heater.
Plastic pipe or dielectric unions may isolate the
water heater electrically. Service and
maintenance personnel who work on or around
the water heater may be standing on wet floors,
and could be electrocuted by an un-grounded
water heater.
CAUTION: Label all wires prior to
disconnection when servicing controls. Wiring
error can cause improper and dangerous
operation. Verify proper operation after
servicing.
The MOBIUS water heater requires an
electrical power supply from 120 VAC 60 Hz
circuit and be properly grounded.

•A means for switching on/off the 120 VAC
power supply must be provided for service
reasons.
•Wire the heater exactly as shown in the
wiring diagram.
•A green screw is provided in the junction
box for grounding connection.
Refer to the wiring diagram. Wiring
diagrams are also located on the inside
panel of the appliance.
Starting Operation
For your safety please read before start
and/or operating.
a) This water heater does not have a pilot. It
is equipped with an electronic ignition
device, which automatically lights the
burner. Do not try to light the burner by
hand.
b) Before operating, smell all around the
water heater area for gas leaking. Be sure
to smell next to the floor because some gas
is heavier than air and will settle towards
the floor.
c) Use only your hand to turn the gas valve
knob. Never use tools. If the knob will not
turn by hand, do not try to repair it, call a
qualified service technician. Force or
attempted repair may result in a fire or
explosion due to the gas leaking.
d) Do not use this water heater if any part has
been under water. Immediately call a
qualified service technician to inspect the
water heater and to replace any parts that
has been under water.
WHAT TO DO IF YOU SMELL THE GAS!
1. Do not try to start the water heater.
2. Do not touch any electric switch; do not
use any phone in your building.
3. Immediately call your gas supplier from
a neighbor’s phone. Follow the gas
supplier’s instructions.
4. If you cannot reach your gas supplier,
call the fire department.
Operating Instructions
The MOBIUS Water Heater is an
instantaneous, tankless water heater designed
to supply your entire household and/or
commercial hot water needs utilizing total
efficiency. The principle behind the MOBIUS
Water Heater is simple. Once you open a hot
water tap, water flows through the MOBIUS
Water heater. The water flow sensor
automatically commands the computer to
electronically ignite the burners and the
computer monitors the water temperature,
water flow rate, and gas flow the insure you get
the right amount of hot water with right
temperature hot water. After the burners have
ignited the “fire on” lamp is lit. Computer will
modulate gas supply to 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 and still keep the heater on.
Now as long as you have water, gas and
electricity, you will get an endless hot water.
Open a hot water tap to turn on your water
heater. Close the hot water tap to turn off your
water heater.
Normal Operation
To Turn on Your MOBIUS water heater.
1. Open a hot water tap.
2. Burners ignite. “Fire On” lamp is lit.
3. Mix with cold water with the hot to get the
correct temperature water.

To Turn off your Mobius water heater
1. Close the hot water tap
“Fire On” lamp extinguishes.
FLOW
The flow rate through the Mobius is limited to a
maximum of 9.6 GPM. The temperature setting,
along with the supply temperature of the water
will determine the flow rate the unit puts out.
Consult the flow charts on the last page of this
manual to determine the possible outlet
temperature and flow rate combinations.
Based on the United States Department of
Energy method of testing water heater output,
the Mobius is rated for 370 gallons per hour, or
6.0 GPM, at a 77°F rise above the inlet
temperature. Refer to the following chart of
typical household flow rates to determine what
the Mobius can do in a household application.
Remember that for bathing, cold water will be
mixed for a comfortable temperature,
increasing the flow output rate.
Start Up
Once you have properly installed the unit,
check the gas and water connections for leaks.
Check for proper ventilation and combustible
air to the heater. Purge the gas and water
lines to remove Air pocket.
Then follow these steps to turn on your unit.
1. Close the manual gas control valve located
on the gas line.
2. Fully open the manual water control valve
on the water supply line.
3. Open a hot water tap, to verify that water
will flow to that tap. Then close the hot
water tap.
4. Fully open the manual gas control valve
installed.
5. Turn on the 120 volt 60 Hz power supply to
the Flash Water Heater.
6. Now you are ready to enjoy hours of
endless hot water.
TURN OFF GAS APPLIANCE
Close the manual gate valve on the gas inlet
line. Then turn off the power supply
Manifold Gas pressure Port
Household Flow Rates
Appliance / Use Flow Rate
(GPM)
Lavatory Faucet 1.0
Bath Tub 4.0
Shower 2.0
Kitchen Sink 1.5
Dishwasher 1.5
Washing Machine 2.0
Taken from UPC 1997

Wiring Diagram
A wiring diagram is located on the inside front panel of the appliance.
Electrical Rating: 120 VAC, 60 Hz, 0.8 A.
Note: If any of the original wiring supplied with this appliance must be replaced, it must be replaced with appliance
wiring material (180c) or its equivalent. Wires are available through the manufacturer.

FOR YOUR SAFETY READ BEFORE OPERATING
A. This water heater does not have a pilot. It is equipped with an electronic ignition
device that automatically lights the burner. Do not try to light the burner by hand.
B. BEFORE OPERATING smell all around the water heater area for gas leaking. Be
sure to smell next to the floor because some gas is heavier than air and will settle
on the floor.
WHAT TO DO IF YOU SMELL GAS.
•Do not try to light any appliance.
•Do not touch any electric switch, do not use any phone in your building
•Immediately call your gas supplier from a neighbor's phone. Follow the gas
supplier's instructions.
•If you cannot reach your gas supplier, call the fire department.
C. Use only your hand to turn the gas valve knob. Never use tools. If the knob will not
turn by hand, don't try to repair it. Call a qualified service technician. Force or
attempted repair may result in a fire of explosion.
D. Do not use this water heater if any part has been under water. Immediately call a
qualified service technician to inspect the water heater and to replace any damaged
parts.
WARNING: If you do not follow these instructions exactly, a fire or
explosion may result causing property damage, personal injury or loss of
life.
OPERATING INSTRUCTIONS
1. STOP! Read the safety information above on this label and Owners Manual.
2. Turn off all electric power to the water heater.
3. Do not attempt to light the burner by hand.
4. Turn the manual gas valve located on the outside of the unit clockwise to the off
position.
5. Wait five (5) minutes to clear out any gas. If you then smell gas. STOP! Follow "B"
in the safety information above on this label. If you don't smell gas, go to next step.
6. Turn the manual gas valve located on the outside of the unit counter clockwise to
the ON position.
7. Turn on all electrical power to the water heater.
8. If the water heater will not operate, follow the instructions " to Turn Off Gas to water
heater" and Call your service technician or gas supplier.
TO TURN OFF GAS TO APPLIANCE
1. Turn off all electric power to the water heater if service is to be performed.
2. Turn the manual gas valve located on the outside of the unit clockwise to the off
position.

Vapors from flammable liquids will explode and catch fire, causing death or severe burns.
Do not use or store flammable products such as gasoline, solvents or adhesives in the
same room or area near the water heater.
The outlet hot water temperature of the MOBIUS water heater is factory set at 140 °F.
WARNING: Use this heater at your own risk. The set outlet water temperature can cause
severe burns instantly or death from scalds. Test the water before bathing or showering.
Do not leave children or the infirm without su
p
ervised.
DANGER
Keep flammable products:
1. Far away from heater.
2. In approved containers.
3. Tightly closed
4. Out of children's reach
Vapors:
1. Cannot be seen
2. Vapors are heavier than air
3. Travels a long way on the floor
4. Can be carried from other rooms to
the main burner by air current.
WARNING: Do not install water heater where flammable products will be stored.
Read and follow water heater warnings and instructions. If owner's manual is
missing, contact the retailer or manufacturer.
WARNING
Hot Water Heater temperature over 125 °F
can cause severe burns instantly or death
from scalding.
Children, disabled and elderly are at the
highest risk of being scalded.
Feel water temperature before bathing or
showering.
Temperature limiting valves are available,
ask professional person.

Applications
Space Heating Application
The FLASH T-K2 can be used for space heating as well as potable heating of hot water applications.
WARNING
•Toxic chemicals such as used for boiler treatments chemical, alcohol, glycerol and glycol
group will not be introduced into the system when used for potable water and space heating.
•The FLASH T-K2 can be used to supply potable water and space heating and shall not be
connected to any heating system or component(s) previously used with non-potable water
where any chemicals were added to the water heating appliances.
•When the system requires water for space heating at temperatures higher than required for
other used, a means such as a mixing valve shall be installed to temper the water for those
uses in order to reduce scald hazard potential.
•Water temperature over 125 °F can cause severe burns instantly or death from scalds.
•Chemicals such as diluted Glycol can be used for radiant floor, Hydro-warm air or Baseboard
heating only.
Basic system drawings and Schematics.
Heating application only:
Warning: This illustration is for concept only. There are a wide variety of variations to the application
of controls and equipment presented applications. Designers must add all necessary safety and
auxiliary equipment to conform to code requirements and design practice.
For more details, contact Technical Department at [phone]
Make u
p
Water Su
pp
l
y
Ex
p
ansion Tank
Pressure Relief Valve Air Vent
Pum
p
Radiant, Hydro or Baseboard
Heating Equipment.