Takagi Mobius T - M1 Installation And Operating Instructions Manual

MOBIUS Water Heater Takagi Industrial Co. USA, Inc.

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

θ ENDLESS HOT WATER SUPPLY
θ ON-DEMAND
θ PILOT LESS SYSTEM
θ COMPACT, SAVE SPACE
θ COMPUTER CONTROL
θ COMPUTERIZED SAFTY
θ CONSERVES ENERGY
θ FULL CAPABILITY FOR MANIFOLD

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

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 Ind ustrial Co. USA Inc.

FOR YOUR SAFETY - This p roduct 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 ca use serious injury or death. Improper
installation and/or operation will void the
warranty.

WARNING:

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.

•

•

•

• 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.

If the information in this

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. Foll ow the
gas supplier’s instructions.
If you cannot reach your gas
supplier, call the fire department.

WARNING: To install this unit correctly, you
must follow the procedures listed in this
manual . Fail ure to do s o will vo i d 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

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

• Re-Circulation …………..22
Temperature Setting …………..23
Manifold Multi Sys tem …………..23

Maintenance and Service …………. 27
Error codes ……...28, 32

Trouble Shooting …………. 29
Component Diagram …………..33
Part List …………. 37
Output temperature Chart …………..39

• 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.

1

SPECIFICATIONS

***

INTRODUCTION

This manual provides information necessary
for the in stalla tion , oper atio n, and ma inte nance
of the MOB IUS Model T -M1 wate r heate r. 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
install a tio n pr oc e dur e s com p let e ly before doi ng
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

trained technician or Gas Company or
manufacturer.

6. WARNING: Do not disconnect the
electrical supply if the ambient
temperat ure s wi ll be r eachi ng fr eezi ng. Th e
Freeze Pr eventi on Device on ly works i f 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 MOBIU S Water Heate r 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.

caused by improper installation (human error).

7. WARNING: Before bathing or showering

FOR YOUR SAFETY

FOR YOUR SAFETY, PLE ASE READ THI S

MANUAL CAREFULLY AND FOLLOW ALL

DIRECTIONS.

1. Follow a ll local code s, or in the a bsence 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.

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 f actor y to ma ximize t he amo unt 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 o r us e gas oli ne or
other flammables, vapors and liquids in the
vicinity of this or any other appliance.

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

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.

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 in s t all.

5. If any problem should occur, turn off all hot
water tap s and turn of f the gas. T hen call a

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 gall ons per minute i s required to tu rn 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
temperat ure contr olle r and/ or th e water hea ter s
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 uni t com es e qui pped wit h h eat er bl ocks 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 pl ugs to drain all th e water out of t he
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, cl ean the water fil ter of any calci um
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 s upply 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
locate d on the gas suppl y li ne .

5. Turn on the power supply to the MOBIUS
Water Heater.

Drain Drain and Filter

INSTALLATION

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.

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. T he 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
functio ns of the rotating fan and ca use
gas not to burn properly. Regular
maintenance is recommended for these
types of envir o nment.

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.

Accessories

Check that all parts listed below were include d

with the unit.

Installation Manual, Warranty Card and

Optional Part Information

Optional It e m s

1. TM-RE10 Temperature Remote Controller

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 fr om 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-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 t o be v ent ed o ut thr oug h a wall . T his 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

The TM-TV06 Vent Cap is for outdoor
installation with the T-M1 water heater. The
cap is inst a ll ed o n th e t op of t h e uni t , in st ea d 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 co des, f ollow t he Nati onal Fu el Gas C ode
ANSI Z221 .23 in US A or in Can ada 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)

Back of heater 1”

Top of heater 36”

24”

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: 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: 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: 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 f eet , Con tact t he m anuf acture r on
how to handle this situation.

INDOOR INSTALLATION

Combustion Air Supply

The water he ater location mus t pr ov i d e e nou gh
air for pr oper c ombusti on and v entilati on of t he
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

Max.

Outside air

area

Inside air

area

59 Sq. IN 235 Sq. IN

235.000
BTU

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 Mak e 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 reve rse the action of the v enting sys tem.
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 ci rcuit or proper devic es 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 dea t h.

This water heater must be vented in
accordance with "Section Venting of
Equipment ", of t he latest ed it io n of the Na ti o n al
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 r est on the water he ater. 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 covere d unde r war r a nty.

Exha ust 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 mi ni m um temperatur e rat i n g of 350 º 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, corrosion­resistant 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 ins talling the vent pipe. Do
not common vent this app lianc e 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.

Indoor installation clearance.

Piping side (Bottom of water

Min. 12”

heater)

Front (Maintenance space) Max. 24”

Min. 4”

Back of heater 1”

Non piping sides (Side of

Min. 1”

water heater)

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/CGA­B149 and local applicable codes.
Locate the vent terminal so that it cannot be
blocked by snow. Most codes require that
terminat ion be at least 12 i nches above gr ade,
but the installer may determine if it should be
higher depending on job site condition and
applicable city code.

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 vertica l pipe a t least 2” high t o 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.

Installation vent terminator Clearance

Gas Supp ly and Gas P i p i n g Sizing

This unit needs a manual gas control valve
(System S hutof f V alve ) tha t m ust be pl aced 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 wil l cause your MOBIU S 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 meas uring the i nlet suppl y pressur e, 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 test ed befor e placi ng th e unit in op erat ion.
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.

1

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

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

Cubic Feet of Natural Gas

Propane Supply Piping

Based on 11” WC supply pressure

Pipe
Size

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 Connectio ns

An approv e d man ual water contr ol v al v e ( wat e r
shutoff valve) mu st be placed on the col d 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 situatio n.

kBTU of Propane

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
warrant y. Make sure the hot and col d 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 (high­temperature) 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
dischar ges periodi cally, this m ay 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. Pr operly protect and
insulate these pipes from freezing.

Electrical Connections

WARNING: The heater must be electrically

grounded. Follow the requirements of the local
authori ty having jurisdicti on. 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
maintena nce p ers onne l who wor k on or aro und
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 a p pliance.

Starting Operation

For your safety please read before start

and/or operating.

This water heater does not have a pilot. It

a)

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 wat er .

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
instant aneous, tankl ess water heat er 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” lam p ext i n gui sh es.

FLOW

The flow ra te thr ou gh the Mo bius i s lim it ed t o a
maximum of 9. 6 GPM. The tem p erat ure s etti ng,
along with the supply temp erature of t he 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 c an do in a household appli cation.
Remember that for bathing, cold water will be
mixed for a comfortable temperature,
increasing the flow output rate.

Household Fl ow Rates

Appliance / Use

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

Flow Rate

(GPM)

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 manu al gas cont rol val ve locat ed
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 APPLIANC E
Close the manual gate valve on the gas inlet

line. Then turn off the power supply

Manifold Gas pressur e Port

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

WARNING: If you do not follow these instructions exactly, a fire or
explosion may result causing property damage, personal injury or loss of
life.

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 a nd 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

• I mmediat ely call your gas s upplier f rom a nei ghbor's phone. Fol low th e gas

supplier's instructions.

• If you cannot reach your gas supplier, call the fire department.

C. Use only your han d t o t urn th e g as v al ve k no b. Ne ve r us e t ool s. If the k n ob wi l l no t

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 u se this wat er heate r if any part has been un der water. Immediat ely call a

qualified service technician to inspect the water heater and to replace any damaged
parts.

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 val ve located on the o utside of the unit clockwi se to the off
position.

5. Wait fi ve (5) mi nutes t o clea r out an y gas. If you t hen s mell gas. ST OP! Fo llow "B "
in the safety information above on this label. If you don't smell gas, go to next step.

6. Turn the ma nual gas valve l ocated on the outs ide of t he unit co unter cl ockwis e to
the ON position.

7. Turn on all electrical power to the water heater.

8. If the wat er h e ate r wi l l not o pe rat e, f ol l ow th e i nst r uct io ns " to T ur n Of f Gas to w ate r
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 val ve located on the o utside of the unit clockwi se to the off
position.

p

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

Keep fl a mmable pr oducts :

WARNING: Use this heater at your own risk. The set outlet water temperature can cause

1. Far away from heater.

2. In approved containers.

3. Tightly closed

4. Out of childre n's reach

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.

The outlet hot water temperature of the MOBIUS water heater is factory set at 140 °F.

severe burns instantly or death from scalds. Test the water before bathing or showering.

Do not leave children or the infirm without su

same room or area near the water heater.

DANGER

WARNING

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.

ervised.

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.

p

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 use d, a means such as a mi xing valve shall be installed to t emper the water for th ose
uses in order to reduce scald hazard potential.

• Water temperature over 125 °F can cause severe burns instantly or death from scalds.

• Ch emicals s uch as dil uted Glycol can be us ed for ra diant flo or, Hydro- warm air or Baseb oard

heating only.

Basic system drawings and Schematics.

Heating application only:

Pressure Relief Valve

Air Vent

Pum

Radiant, Hydro or Baseboard

Heating Equipme nt.

Expansion Tank

Make up Water Supply

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
auxili ary equ i pment to conform to co d e requ ir ements and desig n pract i c e.

For more details, contact Technical Department at [phone]

Dual-purpose hot water heating (Domestic and Heating):

Domestic

potable water

Cold water supply

Pressure Relief Valve

Check Valve

Air Vent

Expansion Tank

Priority Control Devices

Pump

Radiant, Hydro or Baseboard

Heating Equipme nt.

Priorit y Control Devices: It has a capability to m ake priority system that can be used as a cont roller
flow sensor, Aquastat, or electronic controller to controlling radiant, Hydro or baseboard heating
equipments.

Warning: Follow all local codes, or in the absence of local codes, follow the most recent edition of the
National Standard C ode, ANSI Z21. 10.3.

Warning: This illust ration is for c oncept only. T here ar e a wide vari ety of v ariati ons to th e applic ation
of controls and equipment presented applications. Designers must add all necessary safety and
auxili ary equ i pm en t t o conf o rm to co d e requ irements and desig n prac t i c e.

For more details, contact Technical Department at [phone]

T-M1 with Storage Tank

Hot Out Cold In

Relief Valve

Check valve
Hot Water

Recirculation

Recirc. Pump Pump

The maximum flow r ate t hroug h the T -M1 is 9.6 GP M. If it i s nec essar y to a chieve high er fl ow

rates for longer p eriods of time, then it can be ins talled in conjunction with a storage tank. A pump will
be necessary to keep the water hot. We suggest a pump of 1/12 hp or greater depending on the
system.

Recirculation

Pressure Relief Valve

Hot Water to House

Cold inlet ----- --

Hot Water Return

Pump (with/without Timer) Check Valves

This system will also need a pump of 1/12 hp or greater, depending on the ap plication situation. For

more details, contact Technical department at [phone]

Hot Water Output Temperature Setting:

With the MOBIUS Water Heater output hot water temperature can be adjusted either with the optional
remote c ontrolle r (Part TM-R E10, from 95 °F to 176 °F) or manually from the main computer control
boards di pswitch. Dipswitc hes can set four hot water output temper atures 113 °F, 140 °F, 167 °F,
and 176 °F. (Factory set temperature; 140 °F)

Manifold Multi-System Application for Large Volume.

MOBIUS Water Heater has full capability of manifolding multi-systems, with Multi-System Computer
Control (Optional Part TM -RE20). This Mult i-System Comput er Controller, you c an manifold fr om 2
units t o 20 units for commercial and residenti al applicati on with each computer controller.
One comput er (Part TM-RE20) system can make from 26,000 BTU to 4.7 Million BTU system, wit h
fully automatic modulation for large application

Electric Wiring: MOBIUS Water Heater  Model T-M1 Electrical Load: Maximum 0.8 A, 120V per Unit.
Individual cut off switch, even though units have very low electrical load, recommended for multi-

system for the purpose of mainte nance.

Multi System

Main Multi System Controller (TM-RE20) and Temperature Remote Controller (TM-RE10)
wiring:

RE-20 RE-10
201 202 201 202 201 202 201 202

Detail Wiring: T-M1 Comunications cables are inside Box for TM-RE20.
TM-RE10 Cable can be use above 18 gage wire and up to 250 ft.

Wire No. 201 (Male Adapter) and No 202 (Female Adapter)

For TM-RE10

Port.

Use 18 Gage

Wire.

It has four Ports.

Each port can

connect up to Five

T-M1.

No Polarity

Pump Connection:
MOBIUS Water Heater Main Multi Syst em Control ler will b e maintaining setting temp erature insi de

storage tank water with automatically T-M1 ON/OFF Mode.
Circulation Pump between T-M1 system and Storage has to be ON (running) 24- Hour, it will maintain
set temperature.

Pull out jump cable for Store for
activates power port.
Needs power relay for using this
application

Final C heck of the M ulti-S ystem: From MOBIUS Water Heate r Model T -M 1 C om put er Bo ar d, i t has
a jump cable for Single mode or Multi mode. To switch to Multi mode, this jump cable has to be
removed from the T-M1 computer board permanently, but please keep this jump connector safety
stored for future maintenance (this jumper is located behind the “ do not remove” label.

Firing S ystem: Power on each T-M1 and TM-RE20, then TM-RE1 0 will show Num ber 0000 for 20 to
25 second. Next, the RE-10 will show a default temperature setting of 108F this can be changed with
HOT and COLD button located on the TM-RE10. If you press the ON/OFF button this time, RE10
shows curr ent TIME that can be changed, ref er to the instruc tions provided wi th the TM-RE1 0. After
setting of the TIME, press the ON/OFF button, RE-10 will show current Temperature setting.

LP or Natural Gas, Please don’t change
these switch, Factory already set it
correctly.

When unit is firing, this RED LED will
be ON

For Single or Multi mode JUMP cable.
For Multi mode, permanently pull out.

Error signal LED, this LED shows for unit error,
also it will show on RE-10 and RE20. Error codes
are in Installation Manual Boor.

Standby Light with Green LED, ON light mean Unit
is ready to fire.
When Unit is ON, upper RED LED will be ON also.

Maintenance and Service

WARNING: Turn off the electrical power
supply, the manual gas control valve, and
the manual water control valve before
servicing.

Do this immediately after installation.

1. Cleaning the Cold-water inlet filter, refer
to figu r e below .

2. Be sure that all openings for
combustion and ventilation air are not
blocked.

3. Check t hat the exhaust v ent pi pe is not
blocked.

4. Check the gas pressure.

5. Keep the area around the water heater
clear. Remove any combustible
materials, gasoline or any flammable
vapors and liquids.

The unit should be checked once a year or as
necessary by a certified and trained technician.
If repairs are needed, any repairs should be
done by a certified and trained technician.

The following systems and parts should be
checked at least once a year:

1. Venting systems

2. Burners

3. Manual operation of the pressure relief
valve to ensure correct operation.

4. Periodic cleaning of the water filter, refer to
figure below.

5. Heat exchanger. Remove the Thermistor
and check for a mineral coating. A mineral
coatin g on the Therm istor req uires flushi ng
the heat exchanger with a de-scaling

solution. Scale build up will void your
warranty and shorten the life of your water
heater.

Common Trouble Shooting

Water Isn’t Hot Enough

The T-M1 can burn gas at a maximum
input rate of 235,000 BTUH. This puts a
limit on the possible output temperature
and flow capabilities (See flow chart on the
last page of this manual). If the water
doesn’t seem hot enough, compare the
flow a nd tem perat ure t hat i s bein g att ained
to the T-M1 flow vs. temperature chart. If
the uni t is not perf orming acc ording to t he
chart, f irs t check t hat th e gas s uppl y line i s
sized properly, and that the gas pressure is
withi n the re qui red ran ge. If the gas line is
okay, check the plumbing for mixing valves,
thermostatic valves, scald protection,
single handled valves or crossed
connections. If the unit is performing in
accordance with the flow chart, then it may
be undersized for the application. If the
unit is performing according to the chart,
the output temperature can be adjusted
using t he T M-R E10 o r wi th t he di ps witc hes
on the unit.

It Takes Too Long to Get Hot Water

The T-M1 takes three seconds to ignite, and
three more to get up to temperature. The rest
of the time needed for hot water to get to a
fixture is due to the length of piping between
the water heater and the fixture. If the unit
seems to be taking longer than six seconds to
initiate, check the filter and flow sensor for any
debris or damage.

The T-M1 Will Not Initiate

First che ck the flow rate t hrough the un it. If t he
flow is not .75 GPM or greater, the unit will not
initiate. Check the filter and the flow sensor for
any debris or damage.
Press the lower green button on the GFCI
inside the unit. If the red light above it does
not come on, then there is a problem with the
electrical supply to the unit. If that light does

come on, hit t he green reset butt on above the
light, a nd look for the green light on the circui t
plate at the top left of the unit. If this light is not
lit, there is a problem with the electrical
connection between the GFCI and the circuit
plate. Contact Takagi Industrial Company for
Instructions.

Error Codes

All Takagi units are self diagnostic for errors. If
there is a problem with the installation or the
unit, it will give a signal, through a pair of
flashing lights on the circuit plate or error
display on circuit board LED display to
communic ate the source of the pro blem. If the
unit has a TK-RE10 remote control installed,
this will give also give a numerical error code.
Consult t he following chart for the meaning of
an error code:

MOBIUS Water Heater Model T-M1 has a built
in self-diagnostic computer programmed for
safety and convenience for trouble shooting
and maintenance service.

AT the T-M1 Computer Board, a numeric
display will notify of any error displaying a
numeric code when the MOBIUS water heater
has or encounters a problem. This numeric
code will give symptoms for trouble shooting
service and maintenance service.
The T-M1 consists of five major components:
Temperature control, Gas control, Water
control, Burner Control, and Main computer
control.

TK-RE10

Error Code as
Three digit Numeric
numbers

Error N0. Component

031,141,711,741,

751
701

111, 121 Burner Flame

311, 321,331 T emperature control

391,611,721,991 Burner control

501 Gas control

651, 661,541 Water control

101 Combustible Air

Main Computer Cont rol

Temperature Control

(Setting Temp. + over 50

°F)

More detail error code can be found at
Trouble shooting Diagno se Fl ow Chart.

A

(

A

(

A

(

A

(

A

(

A

(

A

)

play

play

y

A

A

①
②

⑰
④

②

⑱

④

B

⑧

Open Valve A
Open Valve B
Open Valve C

Open limit On

Open limit On

Operation Switch ON

③

Dis

Open limit On

Close limit Off

Set Temperature

①

Control Valve B Open Valve B

Power On

Valve A

YES

Valve B

Open limit On

YES

Valve C

YES

Dis

:

: Priorit

Valve A

YES

Pre-check

Normal

Faucet open

Flow Sensor
>=0.75 GPM

YES

Valve C

YES

<=140F

YES

YES

NO

fter 18 sec.)

NO

fter 18 sec.)

NO

fter 18 sec.)

NO

fter 18 sec.)

NO

NO

NO

fter 18 sec.)

NO

C

Valve A failure

Circuit board for valve D.E.F Failure

⑤

High-limit switch off

Open Short:

⑥

Inlet Temp. Thermistor

Open Short:

Output Te mp . Thermistor

Open Short:

Mixing Temp. Thermistor

Circuit board failure

Mismatched gas

Flame failure

Valve C failure

Valve C failure

Valve B failure

bnormal fan rotation

Valve H failure

Gas valve circuit

board failure

Inlet Temp. Thermistor

Output Temp. Thermistor

Mixing Temp. Thermistor

Valve B failure

Valve C failure

Circuit board

bnormal High Temp.

541

711

141

321

311

331

701

031

721

651

541

661

611

Ignite failure

Lost flame

Open Short:

Open Short:

Open Short:

111

121

510

711

321

311

331

661

651

701

Fan off

Operation switch off

Flow sensor off

fter 35 sec.

Maintenance

ll display off

Power off

Faucet close

MOBIUS

Water Heater

Model T-M1

Trouble Shooti ng

Diagnose

Flow - Char t

611

Fan off
Valve H off
Valve D off

Valve E off
Valve G off

Valve F off

Open Valve A

*1

*2

*3

*4

*5 *6

Abnormal Bur ning

High-limit switch

991

141

*13

(

A

(

A

(

A

(

A

(

A

(

A

(

A

(

A

)

(

A

)

play

(

A

)

⑨

⑪

⑦

⑫
⑬

⑭

⑮

⑦

Fan motor rotation

⑩

Fan motor rotation

Proportional control

Check output temp.

*1

Valve A

Open limit On

YES

(<1000rpm)

YES

Fan motor On

(>1000rpm)

YES

No flame

(>0.15μA)

YES

Igniter On

Valve H On
Valve D On
Valve G On

Thermo fuse

Normal

YES

Check flame

(>1.0μA)

YES

Display: Running

Igniter Off

=<203F

YES

Check power

Less normal?

YES

Open Valve B

improperly

*2

NO

fter 18 sec.)

NO

fter 20 sec.)

NO

fter 20 sec.)

NO

NO

fter 5 sec.)

NO

fter 5 sec.)

fter 3 sec.)

NO

fter 10 sec.)

NO

NO

*3

Re-ignite

(=< 2 times)

Valve H Off
Valve D Off
Valve G Off

Igniter Off

Fan Off

YES

< 2 minutes

*4

NO

*5

Display: Running Off

A

NOYES

*6

Valve H Off
Valve D Off
Valve G Off

Valve E Off
Valve F Off

101

D

E

Stop

Faucet close

Flow sensor off

Valve H Off
Valve E Off

Valve F Off

Pass 5 sec.

YES

No flame

(>0.15μA)

YES

Valve D Off
Valve G Off

Flame detection Off

: running Off

Dis

Fan motor Off

Valve B open

Valve A close

Valve A

Close limit On

YES

B C

NO

NO

⑬

510 Blink

A

fter 35 sec.

fter 10 min.

NO

fter 18 sec.

⑨

(

A

)

A

A

YES 661

NO YES

Output temp down

fter 60 sec.

Check power

=< Min. BTU

Valve E Off
Valve F Off

YES

Capacity check

=< Max. BTU

Flow sensor

=< 8.45GPM

Valve C Open

Capacity Check

=> Max. BTU

Flow sensor

=> 8.45GPM

Valve C control

YES

YES

YES

YES

Start

Safety function

NO

E

NO

NO

NO

NO

NO

YES

Valve C Close

Capacity Check

=< Max. BTU

YES

Flow sensor

=< 8.45GPM

YES

Valve C control

bnormal fan rotation

(=<1000rpm)

whendifferential=>±

200rpm with setting

bnormal burning

NO

NO

*13

Max burning power: 12

YES

Check power

=< Mid. BTU

YES

Valve E O n
Valve F Off

Thermocouple

=> 1mV

YES

Thermocouple

=< 10mV

YES

Fan speed up

=>15%

YES

Display: 101

Thermocouple

=< 12mV

NO

NO

NO

YES

NO

NO

D

Valve E O n
Valve F On

Thermocouple

=> 1mV

YES

Thermocouple

=< 10mV

NO

Fan speed up 3%

NO

A

Hi-limit swit ch works

(=>208F)

Circuit board for Valve D

⑥

failure

bnormal high water

temperature

Open Short:

Inlet Temp. Thermistor

Open Short:

Output Te mp . Thermistor

Open Short:

Mixing Temp. Thermistor

Thermo fuse cut off

(=>360F)

<Wter Valve>
Valve A Water Outlet Valve (Two way valve)
Valve B By-Pass Water Control Valve
Valve C Water Control Valve

<Gas Valve>

Valve D Solenoid Valve 1

Valve E Solenoid Valve 2
Valve F Solenoid Valve 3
Valve G Proportional Valve
Valve H Gas Inlet Valve

Error Symptom Error Symptom Error Symptom

31 Wrong Gas Type 331 Mixing Thermistor Fail 701 Abnormal Mixing Thermistor
101 Insufficient Gas Supply 391 Abnormal Thermocouple 711 Abnormal Gas Solenoid Valve
111 Ignition failed 510 Abnormal Main Gas Valve 721 Computer Pre-post Check Problem
121 Loss Flame 541 Abnormal Two-Way Valve 741 Main remote control Trouble
141 Hi-Limit Switch Trip 611 Abnormal Fan Motor 751 Temperature Remote control Trouble
311 Output Thermistor Fail 651 Abnormal Bypass Valve 761 Multi-system Controller
321 Inlet Thermistor Fail 661 Abnormal Output Adjus t Valve 991 Abnorma l Burn ing
211 Vent Pipe 441 Flow Sensor

Display: running off

Flame detector

MOBIUS Water Heater

Parts List and Component Diagram

14

17

18

28

19

20

16

21

29

20

27

52

18

40

26

15

18

22

24

25

23

51

53

54

55

31

30

34

58

57

34

59

56

33

32

35

43

41

36

37

34

38

29

60

26

20

45

31

42

94

34

44

39
40

56

40
63

66

61

65

60

40

62

64

48

47

46

35

48

49

50

1

18

112

111

113

120 117

121

118

119

123

9

126

128

115 114

116

115

122

124

125

127

9

1

3

2

9

6

2

9

0

70

75

81

71

82

10

70

70

74

75

70

69

73

76

9

72

77

74

70

98

8 0

40

43

79

91

95

78

94

9

18

9

97

67

93

68

94

83

90

89

110

10

104

105

3

84

9

88

86

87

10

103
107

108

10

13

3

4

12

11

1

2

3

5

6

2

7

3

8

9

10

Parts List

Part No. Description Part No. Description

1 Case Assembly 65 O-ring P25
2 Brackets 66 Filter
3 Screw (W) M4 x 10 67 Packing
4 Back Guard Panel 68 Combustion Chamber
5 Transformer 69 Burner Assembly
6 Transformer 70 Scr ew M4 x 12
7 Junction Box 71 Wire Holder
8 Junction Box Cover 72 Spark Electrode Holder Packing

9 Screw M4 x 8 73 Sp ark Electrode Holder
10 Sound Insulation 74 Screw M4 x 10
11 Screw M4 x 8 (Coated) 75 Silicon Cap
12 Weather Protection Panel 76 Spark Electrode Fixing Plate
13 Front Cover 77 High Voltage Igniter Cable
14 Exhaust Pipe 78 O-ring (seal)
15 Heat Exchanger Assembly 79 Thermocouple
16 Hi-Limit Switch 80 Thermocouple Fixing Plate
17 Screw M3 x 6 81 Overheat Cut Off Fuse
18 Screw M4 x 10 (coated) 82 Damper
19 Outlet-Thermistor 83 Washer
20 O-ring P4 84 Pressure Sw itch Po rt
21 Heater Block 604 85 Silicon Tube
22 Heat Exchanger Fixing Plate (Back) 86 Pressure Switch
23 Heat Exchanger Fixing Plate (Front) 87 Fan Motor
24 Over Heat Cut Off Fuse Fixing Plate 88 Screw M4 x 12 Hex
25 Over Heat Cut Off Fuse 89 Thermostat
26 Heater Block Fixing Plate 90 Screw (W) M3 x 10
27 Inlet-Thermistor 91 Manifold
28 Two Way Valve Cover 92 Manifold Gas Pressure Port
29 Silicon O-ring M26 93 Gasket
30 Two Way Valve Assembly 94 Screw M4 x 12
31 O-ring P20 95 Manifold Gas Pressure Tap
32 Screw M4 x 8 96 Gas Coupling
33 Quick Release Plate 97 Screw M4 x 8 (Washer & Hex head)
34 O-ring JASO#1017 98 Igniter Fixing Plate
35 Screw M4 x 12 99 Igniter

36 Flange 100 Screw M4 x 6
37 Flow Adjustment Valve 101 Solenoid Valve Wire
38 O-ring P16 102 Proportional Valve Wire
39 Bypass Junction 103 Gas Valve Unit
40 Screw M4 x 6 104 O-ring P22
41 O-ring P18 105 O-ring P18
42 Water outlet Connection 106 Screw M4 x 8
43 Screw M4 x 14 107 O-ring P26
44 Mixing Thermistor 108 Gas Inlet
45 O-ring P6 109 Gas Filter
46 Drain Plug 110 Gas Inlet Fixing Plate
47 Mixing Connection 111 Computer Board
48 Drain Plug Band 112 Computer Board Sticker
49 Water Outlet 113 Mode Port
50 Screw (W) M4 x 12 114 Control Box

* 51 Bypass Flow Adjustment Valve 115 Screw M3 x 25
* 52 Bypass Valve 116 Wire Holder

53 Silicon O-ring M22 117 Terminal Holder
54 Bypass Connection 118 Surge Absorber: A
55 O-ring JASO3#1017 119 Surge Absorber: B
56 Clamp 120 Screw M4 x 16
57 Heater Fixing Plate 121 Terminal
58 Screw M4 x 6 122 Power Distribution Plate
59 Flow Sensor 123 Ground Fault Circuit Interrupter
60 Heater 102 124 Fuse Box
61 Magnetic Protection Plate 125 Fuse
62 O-ring JASO#1019 126 Fuse Cover
63 Screw M4 x 14 (coated) 127 Remote Control Terminal
64 Water Inlet 128 Screw M3 x 12

Out Put Temperature vs. GPM (Max. 9.6 GPM) with Various Ground Water Temperature

Correct Gas pipe size can be expect this chart

12.0

10.0

8.0

6.0

Out Put Hot Water GPM

4.0

2.0

0.0

40 F
50 F
60 F
70 F

90 95 100 105 110 115 120 125 130 135 140 150 160 165 170 175 180

7.7 7.0 6.4 5.9 5.5 5.1 4.8 4.5 4.3 4.0 3.8 3.5 3.2 3.1 3.0 2.8 2.7

9.6 8.5 7.7 7.0 6.4 5.9 5.5 5.1 4.8 4.5 4.3 3.8 3.5 3.3 3.2 3.1 3.0

9.6 8.5 7.7 7.0 6.4 5.9 5.5 5.1 4.8 4.3 3.8 3.7 3.5 3.3 3.2

9.6 8.5 7.7 7.0 6.4 5.9 5.5 4.8 4.3 4.0 3.8 3.7 3.5

Out put Hot Water Temperature

40 F 50 F 60 F 70 F

1