Takagi T-M1 Installation Manual And Owner's Manual

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T-M1 Instantaneous Water Heater

Installation Manual and Owner’s Guide

Mobius Water Heater™

Model T-M1.

Suitable for potable water heating and space heating

FEATURING

• ENDLESS HOT WATER

• ON DEMAND

• COMPACT, SPACE SAVING

• ENERGY CONSERVING

• COMPUTER CONTROLS

• COMPUTERIZED SAFETY

• NO PILOT LIGHT

This product must be installed and
serviced by a licensed plumber, a licensed
gas fitter, or a professional service
technician and/or in accordance with all
local code. Improper installation and/or
operation, or installation by an unqualified
person, will void the warranty.

Operation of this unit creates carbon
monoxide gas and flue gases which can
cause serious injury or death. In addition,
if the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or death.

Takagi Industrial Co. USA Inc.

Irvine, CA 92618

Toll Free [phone] USA

Toll Free [phone] CANADA

www.Takagi.com

ARNING

ARNING

5 Whatney

CONTENTS

Specification …………. 2
Introduction …………..3
For your safety …………..3-4
Installation …………. 5

• General …………. 5

• Accessories …………. 5

• Outdoor Installation ………….5-6

• Indoor Installation ………….6-7

• Venting Instructions …………..7 -9

• Gas Supply/Gas Pipe sizing………..10-11

• Water Connection …………. 11-12

• Electrical Connection …………. 12

• Initial operation …………. 13

Normal operation …………. 13

• Flow …………. 13

• Temperature setting …………. 14

• Wiring diagram …………. 15

• Freeze Protection Device …………. 16

• Maintenance and Service …………..16-17

• Error codes …………..17

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 23.6”x18.5”x8.9”
Ignition Electronic Ignition
Electrical Supply AC 120 V

For your Safety …………..18
Danger …………..19
Application …………..20

• Space Heating …………..20

• Dual-purpose heating …………..21

• Storage Tank …………..22

• Re-Circulation …………..22

Optional Items …………..23
Manifold Multi-system …………24-26
Component Diagram …………27-30
Parts list …………31-32
Output temperature Chart …………..33

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

• This appliance is certified for use at
altitudes from 0ft to 4500ft (1,370m) in
accordance to the latest CAN/CGA 2.17­High Altitude Installation procedures at
normal manifold pressure 2.2"
W.C. (Natural Gas). Do not alter the orifice
jets or gas supply pressure. At altitudes of
4500ft to 5,000ft (1524m) lower the
manifold pressure to 2.0" W.C. (Natural
Gas). At 5000ft to 6000ft (1,829m), lower
the manifold pressure to 1.9" W.C. (Natural
Gas). For elevations above 6000ft or for
specific instructions on how to lower the
manifold pressure, please call the Takagi
office

SPECIFICATIONS

*** NOTE ***

Manufacturer reserves the right to discontinue, or change at any time, specifications or
designs without notice and without incurring obligations.

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INTRODUCTION

This manual provides information necessary
for the installation, operation, and maintenance
of the Model T-M1 water heater. This unit
includes a fan enabling sidewall (power)
venting and an advanced electronic ignition
system.
The model description is listed on the rating
plate which is attached to the front cover of the
water heater. Please read all installation
instructions completely before installing this
product. If you have any problems or
questions regarding this equipment, consult
with Takagi or its local representative.
Experiences have shown that most operating
problems are caused by improper installation.

The T-M1 Water Heater is an instantaneous,
tankless water heater designed to supply
endless hot water to your entire household
and/or commercial facility utilizing total
efficiency. The principle behind the T-M1
Water Heater is simple. Once you open a hot
water tap, water flows through the T-M1 Water
heater. Once a minimum of 0.75 GPM is
achieved, the flow sensor automatically
commands the computer to turn on the fan,
activate the electronic igniter and open the gas
valves. The computer monitors water
temperature, water flow rate and gas flow to
ensure that you get the right amount of hot
water at the correct hot water temperature.
After the burners are ignited, the “fire on” lamp
is lit. The computer will modulate the gas
supply valve and water flow. 0.75 gallons per
minute is required to turn the burners on; after
the burners are ignited, the flow rate can be
lowered to 0.6 gallons per minute to maintain
the heater on. It is advisable to open further
the cold tap rather than decreasing the hot tap
to adjust the water temperature. As long as
you have water, gas and electricity, you will get
an endless flow of hot water. Open a hot water
tap to turn on your water heater. Close the tap
to turn off your water heater.

FOR YOUR SAFETY

The installer is responsible for the correct
installation of your Mobius T-M1 Water
Heater. Installation and service must be
performed by a qualified installer (for
example, a licensed plumber or gas fitter)
otherwise the warranty by Takagi will be
void.

PLEASE READ THIS MANUAL CAREFULLY

AND FOLLOW ALL DIRECTIONS.

1. Follow all local codes, or in the absence of
local codes, follow the most recent edition
of the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 in the USA or the
CAN/CSA B149.1 Natural Gas and
Propane Installation Code in Canada.

2. Properly ground the unit in accordance with
all local codes or in the absence of local
codes, with the National Electrical Codes,
ANSI/NFPA 70 in the USA or CSA
standard C22.1 Canada Electrical Code
Part 1 in Canada.

3. Carefully plan where you intend to install
your T-M1 Water Heater. Ensure that your
heater will have enough combustible air
and proper ventilation and locate your
heater where water leakage will not do
damage to surrounding areas. If there is a
possibility of water damage, install a
suitable drain pan under the unit which will
not restrict combustible airflow.

4. Check the rating plate for the correct gas

type, gas pressure, water pressure and
electrical rating. If this unit does not match
your requirements, do not install.

Rating plate

5. If any problem should occur, turn off all hot
water taps and turn off the gas. Then call a
trained technician or the Gas Company or
the manufacturer.

- 3 -

6. WARNING: Do not disconnect the
electrical supply if the ambient temperature
will drop below freezing. The Freeze
Prevention Device only works if the unit
has electrical power. The Freeze
Prevention Device is rated for temperatures
down to 5 ºF (-15 ºC) in a wind free
environment. Refer to the section on
Winterizing and the Freeze Prevention
Device for more information. The Warranty
will not be covered if the heat exchanger is
damaged due to freezing.

7. WARNING: Water temperatures over
125ºF can cause severe burns instantly or
death from scalding. The water
temperature is set at 122ºF (50ºC) from the
factory to minimize any scalding risk.
Before bathing or showering always check
the water temperature.

8. WARNING: Do not use this appliance if
any part has been in contact with or been
immersed water. Immediately call a trained
technician to inspect and/or service the unit
if necessary.

9. WARNING: Do not store or use gasoline or
other flammables, vapors or liquids in the
vicinity of this appliance.

GENERAL

The T-M1. Water Heater is an instantaneous,
tankless water heater designed to supply
endless hot water to your entire household
and/or commercial facility utilizing total
efficiency. The principle behind the T-M1
Water Heater is simple. Once you open a hot
water tap, water flows through the T-M1 Water
heater. Once a minimum of 0.75 GPM is
achieved, the flow sensor automatically
commands the computer to turn on the fan,
activate the electronic igniter and open the gas
valves. The computer monitors water
temperature, water flow rate, and gas flow to
insure that you get the right amount of hot
water at the correct hot water temperature.
After the burners are ignited, the “fire on” lamp
is lit. The computer will modulate the gas
supply valve and water flow 0.75 gallons per
minute is required to turn the burners on;, after
the burners are ignited, the flow rate can be
lowered to 0.6 gallons per minute to maintain
the heater on. It is advisable to increase the
cold tap rather than decreasing the hot tap to
adjust the water temperature. As long as you
have water, gas and electricity, you will get an
endless flow of hot water. Open a hot water tap
to turn on your water heater. Close the tap to
turn off your water heater.

10. WARNING: Do not reverse the water
and/or gas connections as this will damage
the gas valves and can cause severe injury
or death. Following the diagram below
when installing your water heater:

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INSTALLATION

GENERAL

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

1. The gas regulator is preset at the

factory; it is computer controlled and
should not need adjustment;

2. 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. If you will be installing the unit in a

contaminated area with a high level of
dust, sand, flour, aerosols or other
contaminants, they can become
airborne and enter and buildup within
the fan and burner causing damage to
the unit. The warranty will not cover
damage caused to the unit due to
installation in a contaminated
environment that has not be converted.

5. Particles from these objects may clog

the air vent or reduce the functions of
the rotating fan and cause improper
burning of the gas. 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.

7. Some chemicals used in a beauty salon

may affect the flame sensor. Water
heater may not work properly. Please
consult with Takagi, when the water
heater is installed in a beauty salon.

8. Water hardness may affect the water

heater. Water heater may be damaged.
The warranty will not cover damage
caused by water quality.

Accessories

Check that the installation manual, the
extension cable and the warranty card were
included with the unit.

OUTDOOR INSTALLATION

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/NFPZ 54 in the USA or the CAN/CSA
B149.1 Natural gas and Propane installation
Code in Canada.

The outdoor vent cap must be used when unit
is installed outdoor. Takagi recommends the
use of its part No. TK-TV06.

When installed outdoors, the T-M1 water
heater shall be wall mounted only. Locate the
water heater in an open, unroofed area and
maintain the following minimum clearances:

Outdoor Installation Service Clearances

Piping side (Bottom) 12”

Front (Maintenance space) 24”

Back of heater 1”

Top of heater 36”

Side of heater 2”

- 5 -

WARNING: 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 and void the warranty.

WARNING: Do not install the water heater
vent terminator within 4 feet in the USA of any
air intake or building opening, and with in 3 feet
in Canada of any air intake or building opening.
(Refer to Page.9)

INDOOR INSTALLATION

When installed indoors, the T-M1 water heater
shall be located in an area to maintain the
following minimum clearances around the unit:

Indoor Installation Service Clearances

Piping side (Bottom) 12”

Front (Maintenance space) 24”

Back of heater 1”

Top of heater 12”

Side of heater 2"

The diagram below details the required
clearances around the unit:

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 applicable local
codes. In general, these requirements specify
that if the unit is installed in a confined space,
there must be a permanent air supply opening.

Air Supply from Outside Building

When combustion air is supplied from outside
the building, an opening communicating
directly with the outside should have a
minimum free area of one square inch per
15,000 BTUH input of the total input rating of
water heater in the enclosed area.

Air Supply from Inside Building

When combustion air is supplied from inside
the building, an opening communicating with
the rest of the dwelling should have a minimum
free area of one square inch per 1000 BTUH
input of the total input rating of water heater in
the enclosed area. These openings should
never be less than 100 sq. in.

Minimum recommended air supply opening size
for water heater:

Water heater
size

Max. 235.000

When drawing
make-up air
from outside
the building

When drawing make-up
air from inside the
building (from other
rooms within)

15.7 Sq. IN 235 Sq. IN

BTU

- 6 -

Combustible Air Supplied by
Mechanical fan or Make up air device.

The T-M1 water heater is equipped with a
combustible air sensor that will shut off the unit
when inadequate combustible air supply to unit
is detected.

If a mechanical fan or make up air device 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 device must be wired
(interlocked) with the water heater control
circuit or other 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 the section “Venting of
Equipment" of the latest edition of the Natural
Fuel Gas Code, ANSI Z223.1 and all
applicable local building codes. In Canada,
follow section 7 of the CAN/CSA B149.1
Natural Gas and Propane Installation Code.

Exhaust Vent

This is a Category III appliance and must be
vented accordingly. The vent system must be
sealed air tight. All seams and joints must be
sealed with high heat resistant silicone sealant
or UL listed aluminum adhesive tape having a
minimum temperature rating of 350ºF. For best
results, a vent system should be as short and
straight as possible.

This unit requires 4”, Category III approved,
single wall stainless steel vent pipe or any
other Category III approved, non-combustible,
corrosion-resistant material. The following are
UL listed manufacturers: ProTech Systems Inc.
(FasNSeal), Flex-L Inc., Z-Flex Inc. (Z-Vent III)
and Heat-Fab Inc. (Saf-T Vent). Follow the

vent pipe manufacturer’s instructions when
installing the vent pipe. Do not common vent

this appliance with any other vented appliance.
The maximum length of exhaust vent piping
must not exceed 35 ft. deducting 5 ft. for each
elbow used in the venting system. Do not use
more than 3 elbows.

Diam

eter

4” 3 Ea. 35 ft

For each elbow added, deduct 5 ft. from
max. Vent length.

Horizontal Length

Max.
No. of
Elbow

No. of Elbows Max. Vertical or

Max. Vertical or

Horizontal run in

Length

0 35 ft.
1 30 ft.
2 25 ft.
3 20 ft.

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.

When the horizontal vent run exceeds 5 ft., the
following criteria must be observed:

• Support the vent run at 3 ft intervals with
overhead hangers.

• Slope the vent run downwards toward the
vent terminator at a rate of ¼” per foot.

- 7 -

Vent Termination

A sidewall vent terminator must be used when
the water heater is vented through a sidewall.
Takagi recommends the use of its part No.TK­TV01. The vent terminator 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 with CAN/CSA­B149.1 and local applicable codes.

Locate the vent terminator so that it cannot be
blocked by snow. Most codes require that the
terminator be at least 12 inches above grade,
but the installer may determine if it should be
higher depending on the job site condition and
applicable codes.

WARNING: Improper installation can cause
nausea or asphyxiation, severe injury or death
from carbon monoxide and flue gases
poisoning. Improper installation will void
product warranty. For high altitude installation
above 4,500 feet, contact Takagi on how to
handle this situation.

Roof
Flashing

Rain cap

The exhaust
goes to the roof

General rules for venting the T-M1 water
heater are:

1. Place the water heater as close as possible
to the vent terminator;

2. The vent collar of the water heater must be
fastened directly to an unobstructed vent
pipe.

3. Do not weld the vent pipe to the water
heater collar.

4. The weight of the vent stack must not rest
on the water heater.

5. The vent must be easily removable from
the top of the water heater for normal
service and inspection of the unit.

6. The water heater vent must not be
connected to any other gas appliance or
vent stack.

7. Avoid locating the water heater vent
terminator near any air intake devices or
air-conditioning units. 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.

8. Avoid using an oversized vent pipe or using
extremely long runs of the pipe.

Condensation drain
(Install according to
local code)

TK-TV03 (Back flow
prevention)

z Regarding the clearance from the

terminator to the air inlet or opening,
refer to the next page.

z Install a condensation drain in the

venting.

z Follow the vent system to vent

manufacture’s instruction and local
code.

z Do not common vent or connect any

vent of appliance to the vent.

z Use the 4” category III Vent pipe

approved, single wall stainless steel
vent pipe.

- 8 -

Canada U.S.A

Clearance above grade, veranda, porch,

A

deck, or balcony.
Clearance to window or door that may be

B

opened.
Clearance to permanently closed window * * *

C

Vertical clearance to ventilated soffit located
above the vent terminator within a horizontal

D

distance of 2 feet (61cm) from the center
line of the terminator.
Clearance to unventilated soffit * * *

E

Clearance to outside corner * * *

F

Clearance to inside corner * * *

G

Clearance to each side of center line

H

extended above meter/regulator assembly
Clearance to service regulator vent outlet. 3 feet * *

I

Clearance to non-mechanical air supply inlet
to building or the combustion air inlet to any

J

other application.
Clearance to mechanical air supply inlet. 6 feet 3 feet 3 feet

K

Clearance above paved sidewalk or paved

L

driveway located on public property.
Clearance under veranda, porch deck, or

M

balcony.
*For clearances not specified in ANSI Z223.1 / NFPA 54 or CAN/CSA-B149.1, please use clearances in
accordance with local installation codes and the requirement of the gas supplier.

Direct vent and

other than Direct Vent

1 foot 1 foot 1 foot

3 feet 1 foot

* * *

3 feet * *

3 feet 1 foot

7 feet * 7 feet
1 foot * *

Direct vent Other than Direct Vent

4 feet from below or
side opening. 1 foot

from above opening.

4 feet from below or
side opening. 1 foot

from above opening.

- 9 -

GAS SUPPLY AND GAS PIPE SIZING

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
3 to the off position.

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 manually;

B. BEFORE OPERATING, check all

around the water heater area for
gas leaks. Be sure to check next
to the floor as some gases are
heavier than air and will settle on
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
attempt to repair it. Call a qualified
service technician. Force or
attempted repair may result in a fire
or explosion.

D. WARNING: Conversion of this unit

from natural gas to propane or
propane to natural gas cannot be
done in the field. Contact your local
distributor to get the correct unit for
your gas type. Conversion done by
anyone other than the
manufacturer will void all warranty.

Check that the type of gas matches the rating
plate located on the cover of your water heater.

The minimum and maximum inlet gas pressures
are:

Natural Gas Min. 5” WC - Max. 10.5” WC

Propane Gas M i n . 11” W C - M a x . 1 4 ” W C

Gas pressure below this specified range for the
T-M1 and/or insufficient gas volume will adversely
affect performance. Inlet gas pressure must not
exceed the above maximum values; gas pressure
above the specified range will cause dangerous
operating conditions and damage to the unit. Until
testing of the main gas line supply pressure is
completed, ensure the gas line to the T-M1 is
disconnected to avoid any damage to the water
heater.

Size the gas pipe appropriately to supply the
necessary volume of gas required for the T-M1
(235,000 BTUH) using ANSI233.1/NAPA 54 in
the USA or CAN/CSA B149.1 in Canada or local
codes. Install a manual gas shut-off valve
between the T-M1 and the gas supply line.
When the gas connections are completed, it is
necessary to perform a gas leak test either by
applying soapy water to all gas fittings and
observing for bubbles or by using a gas leak
detection device. Always purge the gas line of
any debris before connecting to the heater gas
inlet.

Pipe Sizing Example: This table below is for
Natural gas piping supply straight to the water
heater without any tabs to other gas appliances

Recommend Gas pipe size for

T-M1 Water Heater(Example for NG)

Distance from Gas Meter Pipe Size (inches)

0' - 20' 3/4"

20' - 70' 1"

70' – 200’ 1-1/4"

- 10 -

Natural Gas Supply Piping

Maximum Capacity of Natural Gas Based on a 0.60 specific gravity at a 0.5” WC pressure drop

Pipe Size kBTU of Natural Gas

Length 10’ 20’ 30’ 40’ 50’ 60’ 70’ 80’ 90’ 100’ 125’ 150’ 200’

¾” 372 255 205 175 156 142 130 121 114 107 95 86 74

1” 702 482 387 331 293 266 245 228 213 202 179 162 139
1 ¼” 1441 990 795 680 603 546 503 468 439 415 367 332 285
1 ½” 2158 1483 1191 1019 903 819 753 701 658 621 550 499 427

2” 4155 2856 2293 1963 1740 1576 1450 1349 1266 1195 1060 960 822

Propane (LP) Gas Supply Piping

Maximum Capacity of Propane (LP) Gas Based on 11” WC supply pressure at a 1.0” WC pressure drop

Pipe Size kBTU of Propane

Length 10’ 20’ 30’ 40’ 50’ 60’ 70’ 80’ 90’ 100’ 125’ 150’ 200’

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

FOR YOUR SAFETY, READ

BEFORE OPERATING:

Do not use this water heater if any part
has been submersed under water.
Immediately call a qualified service
technician to inspect the water heater and
to replace any damaged parts.

All pipes, pipe fittings, valves and other
components, including soldering materials,
must be suitable for potable water systems. A
manual shut off valve must be installed on the
cold water inlet to the water heater between
the main water supply line and the T-M1. In
addition, a manual shut off valve is also
recommended on the hot water outlet of the
unit. If the T-M1 is installed within, or subjected
to, a closed loop water system, such as one
having an anti-backflow device in the cold
water supply line, a thermal expansion tank
must be installed. Contact the water supplier or
local plumbing inspector on how to control this
situation.
After installation of the water heater is
complete, purge the water line to remove all
the debris and air from the line. Failure to do
so may cause damage to the heater. There is

a wire mesh filter within the cold inlet to trap
debris from entering your heater. This will need
to be cleaned periodically to maintain optimum
flow.

Unit Draining & Filter Cleaning Procedures

To drain your unit, please follow these
instructions carefully:

1. Turn off the power supply to the T-M1
Water Heater.

2. Close the manual gas shut off valve
located on the gas supply line.

3. Close 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 residual water flow has ceased,
close all hot water taps.

5. Have a bucket or pan to catch the water
from the unit’s drain plugs. Remove the
drain plugs to drain all the water out of the
unit.

6. Wait a few minutes to ensure all water has
drained from unit.

7. At this time, please check the water filter
located within the cold inlet. With a tiny
brush, clean the water filter of any debris
which may have accumulated and reinsert
the filter back into the cold water inlet.

8. Securely screw the drain plugs back into
place. Hand- tighten only

- 11 -