Giant UGTC-199N User manual

Direct Vent Tankless Water Heater
— Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
— WHAT TO DO IF YOU SMELL GAS
 Do not try to light any appliance.
 Do not touch any electrical switch; do not use any phone in your building.

 If you cannot reach your gas supplier, call the fire department.
—
may result causing property damage, personal injury or death.
WARNING
READ ALL OF THE INSTRUCTIONS THOROUGHLY BEFORE INSTALLING OR OPERATING THIS WATER HEATER.
safety
-29.
performed.
FOR INDOOR APPLICATIONS ONLY
UGTC-199N
UGTC-199P
UGTC-152N
UGTC-152P
ANS Z21.10.3 CSA 4.3
GI-IM045En-0213

2UGTC Series Manual
Table of Contents
This is the safety alert symbol. This symbol alerts you to potenal hazards that can kill or hurt you
and others.
Indicates an imminently hazardous situaon which, if not avoided, will result in death or
serious injury.
Indicates a potenally hazardous situaon which, if not avoided, could result in death or
serious injury.
Indicates a potenally hazardous situaon which, if not avoided, could result in minor or
moderate injury. It may also be used to alert against unsafe pracces.
DANGER
CAUTION
WARNING
Table of Contents..................................................... 2
Safety Denions..................................................... 2
Safety Behaviors and Pracces for the
Consumer and Installer............................................ 3
Installaon Instrucons
(for the licensed professional) ..............................4
Prepare for Installaon...................................... 5
Determine Installaon Locaon ........................ 6
Checklist to Determine Installaon Locaon .. 11
Mount to Wall ................................................. 11
Remove the Front Panel.................................. 11
Installaon of Venng ..................................... 12
Condensate...................................................... 15
Checklist for Venng and Condensate ............ 15
Installaon of Plumbing................................... 16
Checklist for Plumbing..................................... 18
Installaon of Gas Supply ................................ 18
Connect Electricity........................................... 20
Adjust for High Altude (U.S.) ......................... 20
Adjust for High Altude (Canada).................... 20
Adjust for Vent Length..................................... 21
Checklist for Gas and Electricity....................... 21
Installaon of Temperature Controller............ 21
Final Checklist .................................................. 23
Technical Data........................................................ 24
Specicaons................................................... 24
Dimensions ...................................................... 25
Pressure Drop and Water Flow Curves............ 26
Ladder Diagram ............................................... 27
Recirculaon Mode ......................................... 28
Operaon Instrucons....................................... 30
Consumer Operaon Guidelines for the
Safe Operaon of your Water Heater.................... 31
How to Use the Temperature Controller ............... 32
How to Set the Temperature ................................. 33
Diagnosc Codes .................................................... 35
Required Maintenance........................................... 38
Flushing the Heat Exchanger ........................... 40
Manual Draining of the Water Heater............. 41
State Regulaons ................................................... 42
Consumer Warranty............................................... 43
Safety Denions
NOTICE: Giant somemes shares customer contact informaon with businesses that we believe provide
products or services that may be useful to you. By providing this informaon, you agree that we can
share your contact informaon for this purpose. If you prefer not to have your informaon shared with
these businesses, please contact customer service and ask not to have your informaon shared. We
will however, connue to contact you with informaon relevant to the product(s) you registered and/
or you account with us.
If you have any quesons or feel that the manual is incomplete contact Giant at 1-800-363-9354.

UGTC Series Manual 3
CAUTION
 BURN HAZARD. Hot exhaust and vent may cause
serious burns. Keep away from the water heater
unit. Keep small children and animals away from
unit.
 Hot water outlet pipes leaving the unit can be hot
to touch. In residenal applicaons, insulaon
must be used for hot water pipes below 36” due to
burn risk to children.
California law requires this noce to be provided:
California Proposion 65 lists chemical substances known to the state to cause cancer, birth defects, death,
serious illness or other reproducve harm. This product may contain such substances, be their origin from fuel
combuson (gas, oil) or components of the product itself.
Safety Behaviors and Pracces for the Consumer and Installer
 Before operang, smell all around the appliance
area for gas. Be sure to smell next to the oor
because some gas is heavier than air and will sele
on the oor.
 Keep the area around the appliance clear and free
from combusble materials, gasoline, and other
ammable vapors and liquids.
 Combusble construcon refers to adjacent walls
and ceiling and should not be confused with
combusble or ammable products and materials.
Combusble and/or ammable products and
materials should never be stored in the vicinity of
this or any gas appliance.
 Always check the water temperature before
entering a shower or bath.
 To protect yourself from harm, before performing
maintenance:
 Turn o the electrical power supply by
unplugging the power cord or by turning o the
electricity at the circuit breaker. (The
temperature controller does not control the
electrical power.)
 Turn o the gas at the manual gas valve, usually
located immediately below the water heater.
 Turn o the incoming water supply. This can be
done at the isolaon valve immediately below
the water heater or by turning o the water
supply to the building.
WARNING
 Use only your hand to push in or turn the gas
control knob. Never use tools. If the knob will not
push in or turn by hand, do not try to repair it; call a
licensed professional. Force or aempted repair
may result in a re or explosion.
 Do not use this appliance if any part has been under
water. Immediately call a licensed professional to
inspect the appliance and to replace any part of the
control system and any gas control which has been
under water.
 Do not use substute materials. Use only parts
cered with the appliance.
 Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to the
appliance.
 Do not adjust the DIP switch unless specically
instructed to do so.
 Do not use an extension cord or an adapter plug
with this appliance.
 Any alteraon to the appliance or its controls can be
dangerous and will void the warranty.

4UGTC Series Manual
A licensed professional must install the appliance,
inspect it, and leak test it before use. The warranty
will be voided due to improper installaon.
The installer should have skills such as:
 gas sizing
 connecng gas lines, water lines, valves,
electricity,
 knowledge of applicable naonal, state, and
local codes.
 installing venng through a wall or roof
If you lack these skills contact a licensed professional.
Installaon Instrucons
Installaon Steps
Prepare for Installaon ......................................5
Determine Installaon Locaon.........................6
Checklist to Determine Installaon Locaon ...11
Mount to Wall..................................................11
Remove the Front Panel ..................................11
Installaon of Venng......................................12
Condensate ......................................................15
Checklist for Venng and Condensate.............15
Installaon of Plumbing ...................................16
Checklist for Plumbing .....................................18
Installaon of Gas Supply.................................18
Connect Electricity ...........................................20
Adjust for High Altude (U.S.)..........................20
Adjust for High Altude (Canada) ....................20
Adjust for Vent Length .....................................21
Checklist for Gas and Electricity.......................21
Installaon of Temperature Controller............21
Final Checklist...................................................23
General InstruconsInstaller Qualicaons
DO NOT
 Do not install the UGTC-152 or the UGTC-199
outdoors.
 Do not install the appliance in an area where water
leakage of the unit or connecons will result in
damage to the area adjacent to the appliance or to
lower oors of the structure. When such locaons
cannot be avoided, it is recommended that a
suitable drain pan, adequately drained, be installed
under the appliance. The pan must not restrict
combuson air ow.
 Do not obstruct the ow of combuson and
venlaon air. Combuson air shall not be
supplied from occupied spaces.
 Do not use this appliance in an applicaon such as
a pool or spa heater that uses chemically treated
water . (This appliance is suitable for lling large or
whirlpool spa tubs with potable water.)
 Do not use substute parts that are not authorized
for this appliance.
MUST DO
 The installaon must conform with local codes or,
in the absence of local codes, with the Naonal
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
Natural Gas and Propane Installaon Code, CSA
B149.1.
 The appliance, when installed, must be electrically
grounded in accordance with local codes or, in the
absence of local codes, with the Naonal Electrical
Code, ANSI/NFPA 70, or the Canadian Electrical
Code, CSA C22.1.
 The appliance and its appliance main gas valve
must be disconnected from the gas supply piping
system during any pressure tesng of that system
at test pressures in excess of 1/2 psi (3.5 kPa)
(13.84 in W.C.).
 The appliance must be isolated from the gas supply
piping system by closing its individual manual
shuto valve during any pressure tesng of the gas
supply piping system at test pressures equal to or
less than 1/2 psi (3.5 kPa) (13.84 in W.C.).
Type of installaon
 For installaon in residenal and commercial
applicaons.

UGTC Series Manual 5
Prepare for installaon
Parts included
Tools needed
Materials needed
 You must follow the installaon instrucons and
those in Care and Maintenance for adequate
combuson air intake and exhaust.
INFORMATION
 If a water heater is installed in a closed water
supply system, such as one having a backow
preventer in the cold water supply line, means
shall be provided to control thermal expansion.
Contact the water supplier or local plumbing
inspector on how to control thermal expansion.
 Should overheang occur or the gas supply fail to
shut o, turn o the manual gas control valve to
the appliance.
 Keep the air intake locaon free of chemicals such
as chlorine or bleach that produce fumes. These
fumes can damage components and reduce the life
of your appliance.
 Tankless water heater
 MC-91-2 temperature controller (integrated into
the front panel)
 Pipe wrenches (2)
 Adjustable pliers
 Screwdrivers (2)
 Wire cuers
 Gloves
 Safety glasses
 Level
 Manometer
Tools that might be needed
 Hammer drill with
concrete bits
 Saw
 Threading machine with
heads and oiler
 Core drill with diamond
head
 Torch set
 Copper tubing cuer
 Steel pipe cuer
Materials that may be needed
 Soap soluon
 Approved venng
 Teon tape
(recommended) or pipe
compound
 Heat tape
 Pipe insulaon
 Electrical wire and
conduit per local code
 Concrete wall anchors
 Oponal pipe cover
 Oponal temperature
controller
 5/8” ID PVC exible
tubing
 2 conductor 22 AWG
wire for controller
 Single gang electrical
box
 Wire nuts
 Unions and drain valves

6UGTC Series Manual
Consideraon of care for your water heater should
include evaluaon of water quality.
Water that contains chemicals exceeding the levels
below aect and damage the heat exchanger.
Replacement of the heat exchanger due to water
quality damage is not covered by the warranty.
Maximum Level
Total Hardness Up to 200 mg / L
Aluminum * Up to 0.2 mg / L
Chlorides * Up to 250 mg / L
Copper * Up to 1.0 mg / L
Iron * Up to 0.3 mg / L
Manganese * Up to 0.05 mg / L
pH * 6.5 to 8.5
TDS (Total Dissolved Solids) * Up to 500 mg / L
Zinc * Up to 5 mg / L
Determine Installaon Locaon
Environment
Air surrounding the water heater, venng, and vent
terminaon(s) is used for combuson and must be
free of any compounds that cause corrosion of
internal components. These include corrosive
compounds that are found in aerosol sprays,
detergents, bleaches, cleaning solvents, oil based
paints/ varnishes, and refrigerants. The air in beauty
shops, dry cleaning stores, photo processing labs, and
storage areas for pool supplies oen contains these
compounds.
The water heater, venng, and vent terminaon(s)
should not be installed in any areas where the air may
contain these corrosive compounds. If it is necessary
for a water heater to be located in areas which may
contain corrosive compounds, the following
instrucons are strongly recommended.
IMPORTANT CONSIDERATIONS FOR:
Indoor/Internal Water Heaters and Vent
Terminaons of Indoor/Internal Water Heaters
 DO NOT Install in areas where air for combuson
can be contaminated with chemicals.
 Before installaon, consider where air has the
ability to travel within the building to the water
heater.
 Where possible, install the water heater in a
sealed closet so that it is protected from the
potenal of contaminated indoor air.
 Chemicals that are corrosive in nature should not
be stored or used near the water heater.
 Install the water heater terminaon as far away
as possible from exhaust vent hoods.
 Install the water heater terminaon as far away
as possible from air inlet vents. Corrosive fumes
may be released through these vents when air is
not being brought in through them.
 Chemicals that are corrosive in nature should not
be stored or used near the water heater or vent
terminaon.
Damage and repair due to corrosive compounds in
the air is not covered by warranty.
Water Quality
* Source: Part 143 Naonal Secondary Drinking Water
Regulaons
If you install this water heater in an area that is
known to have hard water or that causes scale build-
up the water must be treated and/or the heat
exchanger ushed regularly.
When scale build-up in the heat exchanger begins to
aect the performance of the water heater, a
diagnosc code “LC#” will display. Flush the heat
exchanger to prevent damage to it. Scale build up is
caused by hard water set at a high temperature.
You must ensure that clearances will be met and that
the vent length will be within required limits.
Consider the installaon environment, water quality,
and need for freeze protecon. Requirements for the
gas line, water lines, electrical connecon, and
condensate disposal can be found in their respecve
installaon secons of this manual.

UGTC Series Manual 7
Vent Terminaon Clearances
INSIDE
CORNERDETAIL
FIXED
CLOSED
OPERABLE
FIXED
CLOSED
OPERABLE
B
B
B
A
J
BM
C
F
B
B
E
D
L
G
A
H
K
I
[1] A vent shall not terminate directly above a sidewalk or paved driveway
that is located between two single family dwellings and serves both
dwellings.
[2] Permied only if veranda, porch, deck, or balcony is fully open on a
minimum of two sides beneath the oor.
 For clearances not specied in ANSI Z223.1/NFPA 54, clearances are in
accordance with local installaon codes and the requirements of the gas
supplier.
Clearance to opposite wall is 24 inches (60 cm).
X
V
AIR SUPPLY INLET
VENT TERMINAL
AREA WHERE TERMINAL
IS NOT PERMITTTED
You must install a vent terminaon to bring in combuson air and expel exhaust.
SNOW
TERMINATION
Clearance in
Ref. A also
applies to
anticipated
snow line
Ref Descripon Canadian Installaons US Installaons
AClearance above grade, veranda, porch, deck, or balcony 12 inches (30 cm) 12 inches (30 cm)
BClearance to window or door that may be opened 36 inches (91 cm) 12 inches (30 cm)
CClearance to permanently closed window **
D
Vercal clearance to venlated sot, located above the terminal within
a horizontal distance of 2 feet (61 cm) from the center line of the
terminal
**
EClearance to unvenlated sot **
FClearance to outside corner **
GClearance to inside corner **
HClearance to each side of center line extended above meter/regulator
assembly
3 feet (91 cm) within a height 15
feet (4.5 m) above the meter/ *
IClearance to service regulator vent outlet 36 inches (91 cm) *
JClearance to nonmechanical air supply inlet to building or the 36 inches (91 cm) 12 inches (30 cm)
KClearance to a mechanical air supply inlet 6 feet (1.83 m) 3 feet (91 cm) above if within 10
LClearance above paved sidewalk or paved driveway located on public
property 7 feet (2.13 m) *
MClearance under veranda, porch, deck, or balcony 12 inches (30 cm)  *

8UGTC Series Manual
Addional clearances
Check on whether local codes supersede these
clearances.
 Avoid terminaon locaons near a dryer vent.
 Avoid terminaon locaons near commercial
cooking exhaust.
 You must install a vent terminaon at least 12
inches from the ground.
(0.30 m) between
terminals at same
level
(1.52 m)
vercally
between
terminals
60"
V
V
(1.52 m)
between
terminals at
dierent levels
24"
V
(0.61 m) to wall or parapet
12"
V V
V
60"
V
12"
12"
36"
INSIDE
CORNER
V V
(0.30 m) between
terminals at same
level
(0.30 m ) to
an inside
corner
The vent for this appliance shall not terminate
 Over public walkways; or
 Near sot vents or crawl space vents or other
area where condensate or vapor could create a
nuisance or hazard or cause property damage; or
 Where condensate or vapor could cause damage
or could be detrimental to the operaon of
regulators, relief valves, or other equipment.
Important consideraons for locang vent
terminaon under a sot (venlated or unvenlated
or eave vent; or to a deck or porch)
 Do not install vent terminaon under a sot vent
such that exhaust can enter the sot vent
 Install vent terminaon such that exhaust and
rising moisture will not collect under
eaves. Discoloraon to the exterior of the
building could occur if installed too close.
 Do not install the vent terminaon too close
under the sot where it could present
recirculaon of exhaust gases back into the
combuson air intake part of the terminaon.

UGTC Series Manual 9
Unit clearances
to Combusbles
inches (mm)
to Non-
Combusbles
inches (mm)
Top of Heater 6 * (152) 2 *(51)
Back of Heater 0 (zero) 0 (zero)
Front of Heater 6 (152) 6 (152)
Sides of Heater 2 (51) 1/2 (13)
Ground/Boom 12 (305) 12 (305)
Vent 0 (zero) 0 (zero)
* 0 inches from vent components and condensate drain
line.
The clearance for servicing is 24 inches in front of the
water heater.
For closet installaon, clearance is 6 inches (152 mm from
the front.
The clearance for servicing is 24 inches in front of the
water heater.
to side
to front
to top
to floor/ground
Freeze Protecon
Make sure that in case of freezing weather that the
water heater and its water lines are protected to
prevent freezing. Damage due to freezing is not
covered by the warranty.
Loss of freeze protecon may result in water damage
from a burst heat exchanger or water lines.
With electrical power supplied, the water heater will
not freeze when the outside air temperature is as cold
as –22°F (-30°C) for indoor models, when protected
from direct wind exposure. Because of the “wind-
chill” eect, any wind or circulaon of the air on the
unit will reduce its ability to freeze protect.
The unit may be drained manually. However, it is
highly recommended that drain down solenoid valves
are installed that will automacally drain the unit if
power is lost. These are available in a kit, P/N
15000029-A. (The condensate trap drain plug and
water drain plug are not aected by the auto drain
down solenoid valves and will have to be manually
opened.)
In addion, the solenoid valves should be connected
electrically to a surge protector with terminals. This
allows the solenoid valves to operate if the water
heater is disabled due to a diagnosc code.
The freeze protecon features will not prevent the
external piping from freezing. It is recommended that
hot and cold water pipes are insulated. Pipe cover
enclosures may be packed with insulaon for added
freeze protecon.
It is recommended that the condensate trap drain line
be insulated. A frozen condensate trap drain line
results in diagnosc code 25.
In the event of a power failure at temperatures below
freezing the water heater should be drained of all
water to prevent freezing damage. In addion, drain
the condensate trap and drain line.

10 UGTC Series Manual
Maximum vent length
Maximum vent length with concentric venng
1. Determine the number of 90 degree elbows in
the vent system. (Two 45 degree elbows count as
one 90 degree elbow.)
2. Refer to the table to nd the maximum vent
length based on the number of elbows.
3. Adjust switch No. 1 in the SW1 DIP switch (tan
switches) if required by the applicable note.
 If the length is greater than 21  (6.4 m) then
move switch No. 1 (SW1) to OFF.
 If the length is greater than 15  (4.6 m) then
move switch No. 1 (SW1) to OFF.
 If the length is greater than 9  (2.7 m) then move
switch No. 1 (SW1) to OFF.
Move switch No. 1 (SW1) to OFF.
Example: If you have one elbow then your maximum
vent length is 35 feet (10.7 m). If your
actual length is greater than 15  (4.6 m)
then move switch no. 1 (SW1) to OFF.
Number of
90° Elbows
Maximum vent length
(concentric venng)
041  (12.5 m) 
135  (10.7 m) 
229  (8.8 m) 
323  (7.0 m) 
417  (5.2 m) 
511  (3.4 m) 
65  (1.5 m) 
If you have a longer vent length (see above), switch
No. 1 is required to be in the OFF posion. This
ensures the water heater will run properly. Blocked
ue diagnosc codes and shutdowns may result if
switch No. 1 is not in the correct posion.
NOTICE
Vent length using short radius elbow
Number of
90° Short
Radius
Elbows
Maximum
Straight Vent
Length
Switch #1 in the tan
DIP switches
If length is greater
than:
042  (12.80 m) 18  (5.49 m) move
127  (8.23 m) 3  (0.91 m) move
212  (3.66 m) move switch #1 to OFF
for any length
Number of
90° Long
Radius
Elbows
Maximum
Straight Vent
Length
Switch #1 in the tan
DIP switches
If length is greater
than:
045  (13.72 m) 21  (6.40 m) move
139  (11.89 m) 15  (4.57 m) move
233  (10.06 m) 9  (2.74 m) move
327  (8.23 m) 3  (0.91 m) move
421  (6.40 m)
move switch #1 to
OFF for any length
515  (4.57 m)
69  (2.74 m)
73  (0.91 m)
Vent length using long radius elbow
Maximum vent length for Centrotherm 2 Pipe
InnoFlue Vent System (single wall SW, 3 inch
diameter)

UGTC Series Manual 11
Mount to Wall
wall installaon
brackets
1. Idenfy the installaon locaon and conrm that
the installaon will meet all required clearances.
2. Securely aach the water heater to the wall
using any of the holes in the wall installaon
brackets which are at the top and boom of the
water heater. Ensure that the aachment
strength is sucient to support the weight.
Refer to the weight of the water heater in the
Specicaons secon.
Use a leveling tool to ensure that the water
heater is level. Proper operaon requires that
the water heater be level.
NOTE: The water heater should be installed in an
upright posion. Do not install upside down or on its
side.
Checklist to Determine Installaon
Locaon
□The water heater is not exposed to corrosive
compounds in the air.
□The water heater locaon complies with the
clearances.
□The planned venng will not exceed the
maximum length for the number of elbows used.
□The planned venng terminaon/air intake
locaon meets the clearances.
□The water supply does not contain chemicals or
exceed total hardness that will damage the heat
exchanger.
□A standard 3 prong 120 VAC, 60 Hz properly
grounded wall outlet or other 120 VAC, 60 Hz
source is available.
□The installaon must conform with local codes or,
in the absence of local codes, with the Naonal
Fuel Gas Code, ANSI Z223.1/NFPA 54, or the
Natural Gas and Propane Installaon Code, CSA
B149.1.
□Leave the enre manual taped to the water
heater or give the enre manual directly to the
consumer.
Remove the Front Panel
Slide the plasc trim pieces on each side of the water
heater to expose the screws.
Remove the 4 screws and pull o the front panel.

12 UGTC Series Manual
Installaon of Venng
Install the correct venng for your model according to the venng manufacturer’s instrucons and the
guidelines below. Refer to the manufacturer’s technical literature for specic part numbers and instrucons.
Venng Guidelines
DO NOT
 Do not use PVC, CPVC, ABS or galvanized material
to vent this appliance.
 Do not combine vent components from dierent
manufacturers.
 Vent diameter must not be reduced.
 Do not connect the venng system with an
exisng vent or chimney.
 Do not common vent with the vent pipe of any
other manufacturer’s water heater or appliance.
Giant water heaters can only be common vented
using a Giant cered common vent system.
Common venng is approved for U.S. installaons
only; it is not approved for Canadian installaons.
MUST DO
 This water heater is a direct vent water heater and
therefore is cered and listed with the vent
system. You must use vent components that are
cered and listed with the water heater model.
 The vent system must vent directly to the outside
of the building and use outside air for combuson.
 Avoid dips or sags in horizontal vent runs by
installing supports per the vent manufacturer’s
instrucons.
 Support horizontal vent runs every four feet and
all vercal vent runs every six feet or in
accordance with local codes.
 Venng should be as direct as possible with a
minimum number of pipe ngs.
 Vent connecons must be rmly pressed together
so that the gaskets form an air ght seal.
 The vent piece connected to the water heater
must be secured with one self-tapping screw.
INFORMATION
 Refer to the instrucons of the vent system
manufacturer for component assembly
instrucons.
 If the vent system is to be enclosed, it is suggested
that the design of the enclosure shall permit
inspecon of the vent system. The design of such
enclosure shall be deemed acceptable by the
installer or the local inspector.
NOTICE
If it becomes necessary to access an enclosed vent
system for service or repairs, Giant is not responsible
for any costs or dicules in accessing the vent
system. The warranty does not cover obtaining
access to a vent system in an enclosed environment.
Manufacturer Listed and Tested Vent Products Telephone Fax Contact
Ubbink Rolux Condensing Vent System 800-363-9354 514-640-0969 www.giannc.com
Centrotherm InnoFlue Vent System (single wall
SW, 3 inch diameter) 877-434-3432 518-618-3166 [email protected].com www.centrotherm.us.com
Heat-Fab Saf-T Vent SC system 800-772-0739 413-863-4803 [e-mail],
www.heaab.com
Metal-Fab Corr/Guard Vent/Air Intake System 800-835-2830 316-943-2717 [email protected],
www.metal-fabinc.com
Manufacturer Product Vercal Terminaon Horizontal Terminaon
Ubbink Rolux 96000050-A 96000051-A, 96000052-A
Centrotherm InnoFlue ICRT3539 ISELL0387UV
Heat-Fab Saf-T Vent Saf-T Vent CI Plus Wall Terminaon Saf-T Vent CI Plus Rain Cap
Metal-Fab Corr/Guard 3CGRVDK 3CGRVT

UGTC Series Manual 13
Flue Installaon with Concentric Venng
Install the venng terminaon according to the diagrams and instrucons below.
Secure the first vent component to the water heater
with one self-tapping screw at the hole.
Horizontal Termination
Securing Screw
Vertical Termination
Slope the venting toward the appliance according to
the vent manufacturers installation instructions.
Dispose of condensate per local codes.
Slope the venting toward the appliance according to
the vent manufacturers installation instructions.
Dispose of condensate per local codes.

14 UGTC Series Manual
 Comply with the exhaust clearances found in the Giant Operaon and Installaon Manual.
 Only one appliance can be aached to the vent system.
 Install the system according to the Centrotherm installaon instrucons.
 Use the 3”/5” concentric to twin pipe adaptor and 3” diameter venng.
 The vent terminaon and air intake must be in the same pressure zone.
 Do not exceed maximum straight vent length with number of elbows as shown in the tables on the next
page.
 Maintain the clearances shown in the gures below.
WARNING DO NOT use PVC on the exhaust venng. PVC is allowed on the intake only.
Horizontal Terminaon
Vercal Terminaon
11”
5”
Intake
Oponal
Vent
Flue Installaon with Centrotherm Venng
Install the venng terminaon according to the diagrams and instrucons below.

UGTC Series Manual 15
Condensate
Condensate formaon can occur in high eciency
direct vent appliances. Without proper drainage
condensate will damage the heat exchanger.
To prevent condensate damage follow these
instrucons.
DO NOT
 Do not connect the condensate drain pipe directly
to the rain sewer.
 Do not connect the condensate drain line with an
air condioning evaporator coil drain.
MUST DO
 Use only vent that is approved and idened as
acceptable for your parcular model.
 Slope the venng toward the appliance according
to the vent manufacturers installaon instrucons.
 All condensate must drain and be disposed of
according to local codes.
 Use only corrosion resistant materials for the
condensate drain lines such as PVC pipe or plasc
hose.
 The condensate drain pipe (along its enre length)
must be at least the same diameter as the drain
line, (1/2 inch NPT).
 The end of the condensate drain pipe should be
open to the atmosphere. The end should not be
under water or other substances.
Checklist for Venng and
Condensate
□Verify proper clearances around the vents and air
intakes.
□Ensure you have used the correct venng
products for the model installed and that you
have completely followed the venng
manufacturer’s installaon instrucons and these
installaon instrucons.
□Verify that the vent system does not exceed the
maximum length for the number of elbows used.
INFORMATION
 Water heaters have an integrated condensate
collector.
 Regions of cold climate will create more
condensate in the vent system. The condensate
collector should be used in cold climates.
 The condensate drain pipe should be as short as
possible and have a downward pitch.
 If the condensate drain gets blocked, an diagnosc
code will display on the controller. If this occurs,
the condensate drain must be cleaned.
 The condensate trap will automacally prime (self-
prime) during operaon of the unit as condensate
forms. Condensate draining from the unit
indicates that the trap is full and that there is no
blockage in the condensate drain. It is not
necessary to add water to the condensate trap.
 A condensate neutralizer kit, P/N 50000100-A , is
available from Giant. The kit allows condensate to
ow through neutralizing media that raises the pH
of the condensate to a level that will help prevent
corrosion of the drain and public sewer system.

16 UGTC Series Manual
Installaon of Plumbing
A manual water control valve must be placed in the
water inlet connecon to the water heater before it is
connected to the water line. Unions may be used on
both the hot and cold water lines for future servicing
and disconnecon of the unit.
DO NOT
 Do not introduce toxic chemicals such as those
used for boiler water treatment to the potable
water used for space heang.
MUST DO
 The piping (including soldering materials) and
components connected to this appliance must be
approved for use in potable water systems.
 Purge the water line to remove all debris and air.
Debris will damage the water heater.
 If the appliance will be used as a potable water
source, it must not be connected to a system that
was previously used with a nonpotable water
heang appliance.
 Ensure that the water lter on the water heater is
clean and installed.
Piping Requirements
Pressure Relief Valve Requirements
Install the pressure relief valve according to these
instrucons.
An approved pressure relief valve is required by the
American Naonal Standard (ANSI Z21.10.3) for all
water heang systems, and shall be accessible for
servicing.
DO NOT
 Do not plug the relief valve and do not install any
reducing ngs or other restricons in the relief
line. The relief line should allow for complete
drainage of the valve and the line.
 Do not place any other type valve or shut o
device between the relief valve and the water
heater.
MUST DO
 The relief valve must comply with the standard for
Relief Valves and Automac Gas Shuto Devices for
Hot Water Supply Systems ANSI Z21.22 and /or the
standard Temperature, Pressure, Temperature and
Pressure Relief Valves and Vacuum Relief Valves,
CAN1-4.4.
 The relief valve must be rated up to 150 psi and to
at least the maximum BTU/hr of the appliance.
 The discharge from the pressure relief valve should
be piped to the ground or into a drain system to
prevent exposure or possible burn hazards to
humans or other plant or animal life. Follow local
codes. Water discharged from the relief valve
could cause severe burns instantly, scalds, or
death.
 The pressure relief valve must be manually
operated once a year to check for correct
operaon.
 The relief valve should be added to the hot water
outlet line and near the hot water outlet according
to the manufacturer’s instrucons. DO NOT place
any other type valve or shut o device between
the relief valve and the water heater.
INFORMATION
 If a relief valve discharges periodically, this may be
due to thermal expansion in a closed water supply
system. Contact the water supplier or local
plumbing inspector on how to correct this
situaon. Do not plug the relief valve.
 The American Naonal Standard (ANSI Z21.10.3)
does not require a combinaon temperature and
pressure relief valve for this appliance. However,
local codes may require a combinaon
temperature and pressure relief valve.
Isolaon Valves
Giant strongly recommends the installaon of
isolaon valves on the cold and hot water lines
because they provide the ability to isolate the water
heater from the structure’s plumbing and allow quick
access to ush the heat exchanger. Flushing the heat
exchanger regularly is required as part of the proper
maintenance for this water heater.

UGTC Series Manual 17
Piping Diagram for Basic Installaon
Refer to the Condensate
secon in the venng
instrucons
Water
drain plug
Condensate
trap drain plug
Condensate
drain line
Gas
connecon
Cold water
inlet
Hot water
outlet
The condensate drain pipe (along its enre
length) must be at least the same diameter
as the drain line, (1/2 inch NPT).

18 UGTC Series Manual
Connect Water Heater to Water Supply
Water connecons to the tankless water heater
should follow all state and local plumbing codes.
If this is a standard installaon, refer to the Piping
Diagram for Basic Installaon.
1. Plumb water supply to the tankless water heater
on the 3/4” MNPT connecon at the boom of
the unit marked “Water Inlet”, which is the cold
water supply.
2. Plumb the building hot water supply to the 3/4”
MSPT connecon marked “Water Outlet”, which
is the hot water supply.
If a pipe cover will be installed, make sure water lines
to the water heater t.
Checklist for Plumbing
□Purge the water line of all debris and air by
closing the hot isolaon valve and opening the
cold isolaon valve and its drain. Debris will
damage the water heater. Use a bucket or hose
if necessary.
□Ensure that hot and cold water lines are not
crossed to the unit and are leak free.
□Ensure that a pressure relief valve is installed with
a rang that exceeds the BTU input of the water
heater model. Refer to the rang plate on the
side of the water heater for BTU input.
□Clean the inlet water lter by closing the cold and
hot water inlet isolaon (shut-o) valves. Put a
bucket under the lter at the boom of the water
heater to catch any water that is contained inside
the unit. Unscrew the water lter. Rinse the
lter to remove any debris. Install the lter and
open the isolaon valves.
□Check for proper water pressure to the water
heater. Minimum water pressure is 50 psi. Giant
recommends 60-80 psi for maximum
performance.
Installaon of Gas Supply
MUST DO
 A manual gas control valve must be placed in the
gas supply line to the water heater. A union can be
used on the connecon above the shut o valve
for the future servicing or disconnecon of the
unit.
 Check the type of gas and the gas inlet pressure
before connecng the water heater. If the water
heater is not of the gas type that the building is
supplied with, DO NOT connect the water heater.
Contact the dealer for the proper unit to match the
gas type.
 Check the gas supply pressure immediately
upstream at a locaon provided by the gas
company. Supplied gas pressure must be within
the limits shown in the Specicaons secon with
all gas appliances operang.
 Before placing the appliance in operaon all joints
including the heater must be checked for gas
ghtness by means of leak detector soluon, soap
and water, or an equivalent nonammable
soluon, as applicable. (Since some leak test
soluons, including soap and water, may cause
corrosion or stress cracking, the piping shall be
rinsed with water aer tesng, unless it has been
determined that the leak test soluon is non-
corrosive.)
 Use approved connectors to connect the unit to
the gas line. Purge the gas line of any debris
before connecon to the water heater.
General Instrucons
WARNING
1. If you are not knowledgeable or qualied to
install gas lines or connecons, then contact a
licensed professional to install the gas supply.
2. Turn o 120v power supply.
3. Turn o the gas.
4. Gas is ammable. Do not smoke or provide other
ignion sources while working with gas.
5. Do not turn on the water heater or gas unl all
fumes are gone.

UGTC Series Manual 19
Size the gas pipe
The gas supply must be capable of handling the enre
gas load at the locaon. Gas line sizing is based on
gas type, the pressure drop in the system, the gas
pressure supplied, and gas line type. For gas pipe siz-
ing in the United States, refer to the Naonal Fuel Gas
Code, NFPA 54. The below informaon is provided as
an example. The appropriate table from the applica-
ble code must be used.
1. For some tables, you will need to determine the
cubic feet per hour of gas required by dividing the
gas input by the heang value of the gas
(available from the local gas company). The gas
input needs to include all gas products at the lo-
caon and the maximum BTU usage at full load
when all gas products are in use.
2. Use the table for your gas type and pipe type to
nd the pipe size required. The pipe size must be
able to provide the required cubic feet per hour
of gas or the required BTU/hour.
Example:
The heang value of natural gas for your locaon is
1000 BTU/FT3. The gas input of the UGTC-199N is
199,000 BTU/HR. Addional appliances at the loca-
on require 65,000 BTU/hr. Therefore the cubic feet
per hour = (199,000 + 65,000) / 1000 = 264 FT3/HR. If
the pipe length is 10 feet then the 3/4 inch pipe size is
capable of supplying 264 FT3/HR of natural gas.
Gas Input of all gas products (BTU / HR)
Heang Value of Gas (BTU / FT 3 )
Cubic Feet
per Hour =
(CFH)
 Any compound used on the threaded joint of the
gas piping shall be a type which resists the acon
of liqueed petroleum gas (propane / LPG).
 The gas supply line shall be gas ght, sized, and so
installed as to provide a supply of gas sucient to
meet the maximum demand of the heater and all
other gas consuming appliances at the locaon
without loss of pressure.
INFORMATION
 Refer to an approved pipe sizing chart if in doubt
about the size of the gas line.
Length Pipe Size (inches)
3/4 11 1/4 1 1/2
10 273 514 1060 1580
20 188 353 726 1090
30 151 284 583 873
40 129 243 499 747
50 114 215 442 662
60 104 195 400 600
70 95 179 368 552
80 89 167 343 514
90 83 157 322 482
100 79 148 304 455
Pipe Sizing Table - Natural Gas
Inlet Pressure: less than 2 psi (55 inches W.C.)
Pressure Drop: 0.3 inches W.C.
Specic Gravity: 0.60
Schedule 40 Metallic Pipe
cubic feet per hour
Length Pipe Size (inches)
1/2 3/4 11 1/4
10 291 608 1150 2350
20 200 418 787 1620
30 160 336 632 1300
40 137 287 541 1110
50 122 255 480 985
60 110 231 434 892
80 101 212 400 821
100 94 197 372 763
Pipe Sizing Table - Propane Gas
Inlet Pressure: 11.0 inches W.C.
Pressure Drop: 0.5 inches W.C.
Specic Gravity: 1.50
Schedule 40 Metallic Pipe
Capacity in Thousands of BTU per Hour

20 UGTC Series Manual
Connect Electricity
Do not rely on the gas or water piping to ground the
water heater. A screw is provided in the juncon box
for the grounding connecon.
The water heater requires 120 VAC, 60 Hz power from
a properly grounded circuit.
If using the 5 foot long power cord, plug it into a
standard 3 prong 120 VAC, 60 Hz properly grounded
wall outlet.
The wiring diagram is located on the Technical Sheet
aached to the inside of the front cover.
WARNING
Do not use an extension cord or an adapter plug with
this appliance.
The water heater must be electrically grounded in
accordance with local codes and ordinances or, in the
absence of local codes, in accordance with the
Naonal Electrical Code, ANSI/NFPA No. 70.
Water heaters are equipped with a three-prong
(grounding) plug for your protecon against shock
hazard and should be plugged directly into a properly
grounded three-prong receptacle. Do not cut or
remove the grounding terminal from this plug.
Adjust for High Altude
The gas and power to the water heater should be
turned o. On the SW1 DIP switch (tan switches), set
switches 2 and 3 to the values shown in table below
for your altude. The default seng for the
appliance is 0-2000  (0-610 m) with switches No. 2
and No. 3 in the OFF posion.
When the DIP switch is adjusted, it is not necessary to
adjust the gas pressure seng for high altude.
Altude
SW1
Switch
No. 2
SW1
Switch
No. 3
0-2000  (0-610 m) OFF OFF
2001-5200  (610-1585 m) OFF ON
5201-7700  (1585-2347 m) ON OFF
7701-10200  (2347-3109 m) ON ON
120V Wiring
Blue or Black wire: hot leg
Brown or White Wire: neutral
Adjust for High Altude
610 - 1372 m (2001 - 4500 )
for Canada Only
The gas and power to the water heater should be
turned o. On the SW1 DIP switch (tan switches),
set switches 2 and 3 to the values shown in table
below for your altude. The default seng for the
appliance is 0-2000  (0-610 m) with switches No. 2
and No. 3 in the OFF posion.
When the DIP switch is adjusted, it is not necessary
to adjust the gas pressure seng for high altude.
Altude
SW1
Switch
No. 2
SW1
Switch
No. 3
0-2000  (0-610 m) OFF OFF
2001-4500  (610-1372 m) OFF ON
The conversion shall be carried out by a manufactur-
er’s authorized representave, in accordance with the
requirements of the manufacturer, provincial or terri-
torial authories having jurisdicon and in accord-
ance with the requirements of the CAN/CGA-B149.1
or CAN/CGA-B149.2 Installaon Codes