Laars Pennant PNCH User manual

Installation and Operation Instructions Document 1204E
H2319100E
Installation and Operation
Instructions for
Low Temperature
PENNANT™
Hydronic Boiler
Model PNCH
Water Heater
Model PNCV
FOR YOUR SAFETY: This product must be installed and serviced by a professional service technician,
qualified in hot water boiler installation and maintenance. Improper installation and/or operation could
create carbon monoxide gas in flue gases which could cause serious injury, property damage, or
death. Improper installation and/or operation will void the warranty. For indoor installations, as an
additional measure of safety, Laars strongly recommends installation of suitable Carbon Monoxide
detectors in the vicinity of this appliance and in any adjacent occupied spaces.
WARNING
If the information in this manual is not
followed exactly, a fire or explosion may
result causing property damage, personal
injury or loss of life.
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.
• Immediately call your gas supplier from
a nearby phone. Follow the gas supplier's
instructions.
• If you cannot reach your gas supplier, call
the fire department.
Installation and service must be performed
by a qualified installer, service agency, or gas
supplier.
AVERTISSEMENT
Assurez-vous de bien suivres les instructions
données dans cette notice pour réduire au
minimum le risque d’incendie ou d’explosion ou
pour éviter tout dommage matériel, toute blessure
ou la mort.
Ne pas entreposer ni utiliser d’essence ni d’autres
vapeurs ou liquides inflammables dans le voisinage
de cet appareil ou de tout autre appareil.
QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ:
• Ne pas tenter d’allumer d’appareils.
• Ne touchez à aucun interrupteur. Ne pas vous
servir des téléphones dansle bâtiment où vous
trouvez.
• Appelez immédiatement votre fournisseur de
gaz depuis un voisin. Suivez les instructions
du fournisseur.
• Si vous ne pouvez rejoindre le fournisseur de
gaz, appelez le sservice des incendies.
L’installation et l’entretien doivent être assurés par
un installateur ou un service d’entretien qualifié ou
par le fournisseur de gaz.
Heating Systems Company
A subsidiary of CorporationBRADFORD WHITE
®
®

LAARS Heating Systems
Page 2
SECTION 1. General Information
1.1 Introduction...................................................... 3
1.2 Model Identication.......................................... 4
1.3 Warranty .......................................................... 4
1.4 Dimensions...................................................... 4
1.5 Locating the Appliance..................................... 4
1.6 Locating Pump-Mounted Water Heater
with Respect to Storage Tank(s)...................... 6
1.7 Locating Pump-Mounted Boiler with
Respect to Return/Supply Header................... 6
1.8 Locating Appliance for Correct
Horizontal Vent/Ducted Air Distance
From Outside Wall ........................................... 6
SECTION 2. Venting and Combustion Air
2.1 Combustion Air ................................................ 7
2.1.1 Combustion Air From Room ............................ 7
2.1.2 Intake Combustion Air...................................... 7
2.2 Venting............................................................. 8
2.2.1 Vent Categories ............................................... 8
2.2.2 Category I Vent................................................ 8
2.2.3 Common Venting Systems .............................. 8
2.2.4 Category III Vent.............................................. 9
2.3 Locating Vent & Combustion Air Terminals...... 9
2.3.1 Side Wall Vent Terminal................................... 9
2.3.2 Side Wall Combustion Air Terminal................ 12
2.3.3 Vertical Vent Terminal .................................... 12
2.3.4 Vertical Combustion Air Terminal................... 12
2.4 Common Vent Test – Boilers ......................... 12
2.5 Vent Terminals for Outdoor Units................... 13
SECTION 3. Gas Supply and Piping
3.1 Gas Supply and Piping .................................. 14
SECTION 4A.
Water Connections – Pennant Boiler
4A.1 Heating System Piping:
Hot Supply Connections – Boiler................... 16
4A.2 Cold Water Make-Up – Boiler ........................ 16
4A.3 Water Flow Requirements – Boiler ................ 16
4A.4 Freeze Protection – Boiler ............................. 16
SECTION 4B. Water Connections –
Pennant Water Heater
4B.1 Water System Piping – Water Heater ............ 17
4B.2 Hot Water Supply Piping – Water Heater ...... 17
4B.3 Water Flow Requirements – Water Heater .... 17
4B.4 Combined Water (potable)
Heating and Space Heating........................... 17
4B.5 Freeze Protection – Water Heater................. 17
SECTION 5. Electrical Connections
5.1 Main Power.................................................... 20
5.1.1 Sizes 500-1500.............................................. 21
5.1.2 Sizes 1750-2000............................................ 21
5.1.3 Separate Pump Circuit................................... 21
5.1.4 All Sizes......................................................... 21
5.2 Field Wiring ................................................... 21
5.3 Low Water Cut-Off ........................................ 22
SECTION 6. Operating Instructions
6.1 Filling the Boiler System ................................ 28
6.2 Sequence of Operation.................................. 28
6.3 Temperature (Operating) Control................... 29
6.3.1 Temperature Control Overview...................... 29
6.3.2 Programming Parameters-Boilers ................. 29
6.3.3 Programming Parameters-Water Heaters ..... 30
6.4 Limit Controls................................................. 30
6.5 Operating the Burner and Set Up .................. 30
6.5.1 Set Up for 0 to 2500 Feet Altitude.................. 30
6.5.2 High Altitude Adjustment and Set Up............. 31
6.6 Shutting Down the Pennant........................... 31
6.7 To Restart the Pennant.................................. 31
SECTION 7. Maintenance
7.1 System Maintenance ..................................... 32
7.2 Appliance Maintenance and
Component Description ................................. 32
7.2.1 Burners .......................................................... 32
7.2.2 Filter............................................................... 33
7.2.3 Gas Valves..................................................... 33
7.2.4 Manual Reset High Limit Control................... 33
7.2.5 Automatic Reset High Limit Control............... 33
7.2.6 Temperature Control...................................... 33
7.2.7 Ignition Control............................................... 33
7.2.8 Ignitor............................................................. 34
7.2.9 Transformer ................................................... 34
7.2.10 Blowers.......................................................... 34
7.2.11 Flow Switch.................................................... 34
7.2.12 Heat Exchanger Coil...................................... 34
SECTION 8. Trouble Shooting
8.1 Resolving Lockouts........................................ 35
8.2 Delayed Ignition – Possible Causes .............. 35
8.3 Short Cycling – Boiler .................................... 35
8.4 Short Cycling – Water Heater ........................ 36
8.5 High Gas Consumption.................................. 36
8.6 Troubleshooting Pennant Controls ................ 36
SECTION 9. Replacement Parts
9.1 General Information....................................... 36
9.2 Parts List........................................................ 36
TABLE OF CONTENTS

Low Temperature Pennant Page 3
SECTION 1.
General Information
USING THIS MANUAL – Because the
Pennant Boilers and Pennant Water Heaters are
identical appliances, with the exception of materials
of manufacture, labels and ultimate use application,
this manual provides information for the proper
installation, operation and maintenance of both
products. Where differences exist between the
application of the appliances and their operation,
the sections pertinent to only one appliance or the
other will be so identied.
In the Commonwealth of Massachusetts, this
appliance must be installed by a licensed plumber or
gas tter.
WARNING
To minimize the risk of electric shock, fire or other
hazards which could result in property damage,
injury, or death. The Pennant hydronic, boiler or
water heater must be installed in accordance with
the procedures detailed in this manual, or the Laars
Heating Systems warranty may be voided. The
installation must conform to the requirements of
the local jurisdiction having authority, and, in the
United States, to the latest edition of the National
Fuel Gas Code, ANSI Z223.1/NFPA54. In Canada,
the installation must conform to the latest edition
of the Natural Gas and Propane Installation Code,
CSA B149.1 and/or applicable local codes. Where
required by the authority having jurisdiction, the
installation of Pennant appliances must conform
to the Standard for Controls and Safety Devices
for Automatically Fired Boilers, ANSI/ASME
CSD-1. Any modifications to the boiler, its gas
controls, or wiring may void the warranty. If field
conditions require modifications, consult the factory
representative before initiating such modifications.
1.1 Introduction
This manual provides information necessary for
the installation, operation, and maintenance of Laars
Heating Systems’ Low temperature Pennant copper
tube appliances, sizes 500-2000 (standard appliances
are covered in a separate manual). Read it carefully
before installation.
AVERTISSEMENT
Afin de réduire au minimum les risques de
commotion électrique, de feu ou d’autre nature,
qui pourraient causer des dommages matériels,
des blessures ou des accidents mortels, les
chaudières à eau chaude ou les chauffe-eau
Pennant doivent être installés conformément aux
directives détaillées contenues dans ce manuel, à
défaut de quoi la garantie fournie par Laars Heating
Systems serait annulée. L’installation doit être
conforme aux exigences de la réglementation locale
en vigueur et, aux États-Unis, à l’édition la plus
récente du Natural Fuel Gas Code (Code pour le
gaz combustible naturel) ANSI Z223.1/NFPA54. Au
Canada, l’installation doit respecter les exigences
de la plus récente édition du Code d’installation du
gaz naturel et du propane CSA B149.1, et/ou des
codes locaux de construction en vigueur. Lorsque
la réglementation locale l’exige, l’installation des
appareils électroménagers Pennant doit respecter
les exigences du Standard for Controls and Safety
Devices for Automatically Fired Boilers (Code pour
les équipements de commande et de sécurité des
chaudières à combustion automatique), ANSI/
ASME CSD-1. Toute modification apportée à la
chaudière, aux régulateurs de gaz ou au câblage,
peut compromettre la garantie. Si certaines
conditions particulières rendent des adaptations
nécessaires, consulter un représentant du fabricant
avant d’entreprendre ces modifications.
All application and installation procedures
should be reviewed completely before proceeding with
the installation. Consult the Laars Heating Systems
factory, or local factory representative, with any issues
or questions regarding this equipment. Experience
has shown that most operating issues are caused by
improper installation.
The Pennant appliance is protected against over
pressurization. A pressure relief valve is tted to all
appliances. It is installed on the outlet header, at the
water outlet of the appliance.
IMPORTANT: The inlet gas pressure to the appliance
must not exceed 13 in. w.c. (3.2 kPa).
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
P N C A C C 2
SERIES
P N C
USAGE
H
V
SIZE
0 5 0 0
0 7 5 0
1 0 0 0
1 2 5 0
1 5 0 0
1 7 5 0
2 0 0 0
FUEL
N
P
ALTITUDE
A
FIRING
MODE
CON-OFF
LOCATION
C
REVISION
2
HEAT
EXCHANGER
B
C
N
P
OPTIONS
CODE
X
J
PUMP
OPTIONS
H
N
S
C
B
D

LAARS Heating Systems
Page 4
All installations must be made in accordance
with:
1) In the U.S., the " National Fuel Gas Code "ANSI
Z223.1/NFPA54, Latest Edition and all applicable
local codes as required by the Authorities Having
Jurisdiction (AHJ), or
2) In Canada, the "Natural Gas and Propane
Installation Code", CSA B149.1, latest edition and all
applicable local codes as required by the AHJ.
All electrical wiring is to be done in accordance with:
1). In the U.S., the "National Electrical Code" (NEC),
ANSI/NFPA 70, latest Edition and all applicable local
codes as required by the AHJ, or
2). In Canada, the “Canadian Electrical Code - Part
1”, CSA STD. C22.1 and all applicable local codes as
required by the AHJ.
This appliance must be electrically grounded in
accordance with the applicable codes and standards
referenced above.
1.2 ModelIdentication
Consult the rating plate on the unit. The
following information describes the model number
structure.
Model Character Designation
1-3 Model Series Designation
P N C = Pennant
4 Usage
H = Hydronic
V = Volume Water
5-8 Size
0 5 0 0 = 500,000 BTU/h input
0 7 5 0 = 750,000 BTU/h input
1 0 0 0 = 999,000 BTU/h input
1 2 5 0 = 1,250,000 BTU/h input
1 5 0 0 = 1,500,000 BTU/h input
1 7 5 0 = 1,750,000 BTU/h input
2 0 0 0 = 1,999,000 BTU/h input
9 Fuel
N = Natural Gas
P = Propane
10 Altitude
A = 0-10,000 feet
11 Location
C = Indoor and Outdoor
12 Firing Mode
C = On-Off
13 Revision
2 = Revision Level 2
14 Heat Exchanger
B = Glass-lined CI / copper / brz trim (std. PNCV)
C = Glass-lined cast iron / copper (std. PNCH)
N = Glass-lined cast iron / cu-nickel
P = Glass-lined cast iron / cu-nickel / brz trim
15 Option Code
X = Standard Low Temp Control
J = CSD-1, FM, IRI, IL
16 Pump Options
H = TACO, Hard water pump (PNCV only)
N = TACO, Normal water pump
S = TACO, Soft water pump (PNCV only)
C = B&G, Hard water pump (PNCV only)
B = B&G, Normal water pump
D = B&G, Soft water pump (PNCV only)
1.3 Warranty
Laars Heating Systems’ appliances are covered
by a limited warranty. Owners should submit online
warranty registration at www.Laars.com.
All warranty claims must be made to an authorized
Laars Heating Systems representative, directly to
Customer Service, or online at www.Laars.com.
Claims must include the serial number and model
(this information can be found on the rating plate),
installation date, and name of the installer. Shipping
costs are not included in the warranty coverage.
Some accessory items are shipped in separate
packages. Verify receipt of all packages listed on
the packing slip. Inspect everything for damage
immediately upon delivery, and advise the carrier of
any shortages or damage. Any such claims should be
led with the carrier. The carrier, not the shipper, is
responsible for shortages and damage to the shipment
whether visible or concealed.
1.4 Dimensions
See Figure 1.
1.5 Locating the Appliance
The appliance should be located to provide
clearances on all sides for maintenance and inspection.
It should not be located in an area where leakage of
any connections will result in damage to the area
adjacent to the appliance or to lower oors of the
structure.
When such a location is not available, it is
recommended that a suitable drain pan, adequately
drained, be installed under the appliance.
The appliance is design certied by CSA-
International for installation on combustible ooring;
in basements; in closets, utility rooms or alcoves.
Pennant Boilers or Water Heaters must never be
installed on carpeting. The location for the appliance
should be chosen with regard to the vent pipe lengths
and external plumbing. The unit shall be installed such
that the gas ignition system components are protected
from water (dripping, spraying, rain, etc.) during
operation and service (circulator replacement, control
replacement, etc.). When vented vertically, the Pennant
must be located as close as practical to a chimney or
outside wall. If the vent terminal and/or combustion
air terminal terminate through a wall, and there is
potential for snow accumulation in the local area, both
terminals should be installed at an appropriate level

Low Temperature Pennant Page 5
13.7
35
B
C
W*
V*
A
12.4
31
H20.24
514
FRONT VIEW
REAR VIEW
W* V*
TOP VIEW
FLOW SWITCH
INLET
OUTLET
3WAY ACTUATOR
TEMPERATURE
SWITCH
PRV
F
(W)
2
5
LEFT SIDE VIEW
PUMP
PUMP
G
(V)
19.7
50
41.5
105 35.3
89
29.3
74
7.75
20
13.8
35
13.7
35
RIGHT SIDE VIEW
D
C
W*
B
V*
E
Dimensions shown in
inches cm
Figure 1. Dimensional Data.
Size A B C D E F G H
Air
Conn.
W*
Vent
Conn.
V*
Horiz.
Vent
Pipe
500 33½ 85 15¾ 40 5¾ 15 29¾ 76 33¾ 86 7¾ 20 8¾ 22 46 117 615 820 615
750 45½ 116 21¾ 55 5¾ 15 29¾ 76 33¾ 86 7¾ 20 8¾ 22 58 147 820 10 25 820
1000 57½ 146 28¾ 73 5¾ 15 29¾ 76 33¾ 86 7¾ 20 718 70 178 820 10 25 820
1250 68 172 34 86 101∕826 30¾ 78 311∕879 8¾ 22 8¾ 22 80 203 12 30 12 30 820
1500 78½ 199 39¾ 101 101∕826 30¾ 78 311∕879 8¾ 22 8¾ 22 91 231 12 30 12 30 820
1750 89 226 44½ 113 101∕826 30¾ 78 311∕879 8¾ 22 8¾ 22 101 256 12 30 14 36 820
2000 99½ 253 49¾ 126 101∕826 30¾ 78 311∕879 8¾ 22 8¾ 22 112 284 12 30 14 36 12 30
*Air and vent connections may be on top or back of the Pennant, and are eld convertible. Dimensions in inches cm
ØØ

LAARS Heating Systems
Page 6
above grade such that blockage of the terminal from
accumulated debris or precipitation is prevented.
The dimensions and requirements that are shown
in Table 1 should be met when choosing the locations
for the appliance.
1.6 Locating Pump-Mounted Water Heater
with Respect to Storage Tank(s)
For best results, the Pennant water heater should
be located within 15 feet (4.6m) of the storage tank(s).
The pump is sized for 30 feet (9.1m) of piping.
If the appliance must be installed with longer
piping runs, then larger diameter pipe or tubing may be
acceptable. Consult the factory for assistance.
Appliance
Surface
Required
Clearance From
Combustible Material
Recommended
Service Access
Clearance
inches cm inches cm
Left Side 12.5 24 61
Right Side 12.5 24 61
Top 12.5 12 30
Back 12.5 12** 30**
Front 12.5 36 91
Vertical
(Category 1)
Vent
6* 15.2*
Horizontal
(Category 3)
Vent
per UL 1738 venting
system supplier's
instructions
*1" (2.5 cm) when b-vent is used.
**When vent and/or combustion air connects to the back,
recommended clearance is 36" (91cm).
Table 1. Clearances.
1.7 Locating Pump-Mounted Boiler with
Respect to Return/Supply Header
For the best results, Pennant should be located
within 15 feet (4.6m) of the supply and return headers.
The pump is sized for 30 feet (9.1m) of piping.
If the appliance must be installed with longer
piping runs, then larger diameter tubing may be
acceptable. Consult the factory for assistance.
1.8 Locating Appliance for Correct
Horizontal Vent/Ducted Air Distance
From Outside Wall
The forced draft combustion air blower(s) in the
appliance has/have sufcient power to pull air and vent
properly when the guidelines for horizontal air and
vent are followed (see Table 2).
NOTE: On some models, the vent collar size is
larger than the size of the vent pipe that can be
used. Vent collar size and horizontal pipe diameters
can be found in Table 1. The larger vent collar
size is to accommodate Category I (vertical) vent
systems.
NOTE: When located on the same wall, the
Pennant combustion air intake terminal must
be installed a minimum of 12" (30cm) below the
exhaust vent terminal and separated by a minimum
of 36 inches (91cm) horizontally.
The air intake terminal must be installed high
enough to avoid blockage from snow, leaves and other
debris.
HORIZONTAL INTAKE AIR
VENT COLLAR VENT PIPE PIPE MAX. PIPE MAX. NO. SIDE WALL SIDE WALL
SIZE SIZE DIAMETER DIAMETER LENGTH OF ELBOWS VENT COMBUSTION
TERMINAL AIR TERMINAL
in. cm in. cm in. cm ft. mPART NUMBER PART NUMBER
500 820 615 615 50 15 3 CA001401 20260701
750 10 25 820 820 50 15 3 CA001402 20260703
1000 10 25 820 820 50 15 3 CA001402 20260703
1250 12 30 10 25 10 25 50 15 3 CA001405 20260705
1500 12 30 10 25 10 25 50 15 3 CA001405 20260705
1750 14 36 12 30 12 30 50 15 3 CA001404 20260706
2000 14 36 12 30 12 30 50 15 3 CA001404 20260706
Table 2. Horizontal Vent / Combustion Air Parameters.

Low Temperature Pennant Page 7
SECTION 2.
Venting and Combustion Air
WARNING
For indoor installations, as an additional measure
of safety, Laars strongly recommends installation of
suitable Carbon Monoxide detectors in the vicinity of
this appliance and in any adjacent occupied spaces.
AVERTISSEMENT
Pour des installations intérieures, Laars
recommande fortement, comme mesure de sécurité
supplémentaire, l’installation de détecteurs de
monoxyde de carbone adaptés dans le voisinage
de l’appareil et dans chacune des pièces habitées
adjacentes.
2.1 Combustion Air
Pennant boilers and water heaters must have
provisions for combustion and ventilation air in
accordance with the applicable sections addressing
requirements for air for combustion and ventilation of
the National Fuel Gas Code, ANSI Z223.1. In Canada,
the applicable sections of the Natural Gas and Propane
Installation Code (CSA B149.1) must be followed. In
all cases any and all applicable local installation codes
must also be followed.
A Pennant appliance may receive combustion
air from the space in which it is installed, or it can be
ducted directly to the unit from the outside. Proper
ventilation air must be provided in either case.
2.1.1 Combustion Air From Room
In the United States, the most common
requirements specify that the space shall communicate
with the outdoors in accordance with method 1 or 2,
which follow. Where ducts are used, they shall be of
the same cross-sectional area as the free area of the
openings to which they connect.
Method 1: Two permanent openings, one
commencing within 12 inches (30 cm) of the top
and one commencing within 12 inches (30 cm) of
the bottom, of the enclosure shall be provided. The
openings shall communicate directly, or by ducts,
with the outdoors or spaces that freely communicate
with the outdoors. When directly communicating
with the outdoors, or when communicating to the
outdoors through vertical ducts, each opening shall
have a minimum free area of 1 square inch per 4000
Btu/hr (5.5 square cm/kW) of total input rating of all
equipment in the enclosure. When communicating to
the outdoors through horizontal ducts, each opening
shall have a minimum free area of not less than
1 square inch per 2000 Btu/hr (11 square cm/kW) of
total input rating of all equipment in the enclosure.
Table 3 shows data for this sizing method, for each
Pennant model.
Method 2: One permanent opening, commencing
within 12 inches (30 cm) of the top of the enclosure,
shall be permitted. The opening shall directly
communicate with the outdoors or shall communicate
through a vertical or horizontal duct to the outdoors
or spaces that directly communicate with the outdoors
and shall have a minimum free area of 1 square inch
per 3000 Btu/hr (7 square cm/kW) of the total input
rating of all equipment located in the enclosure. This
opening must not be less than the sum of the areas of
all vent connectors in the conned space.
Other methods of introducing combustion and
ventilation air are acceptable, providing they conform
to the requirements in the applicable codes listed
above.
In Canada, consult local building and safety
codes or, in absence of such requirements, follow
CSA B149.1, the Natural Gas and Propane Installation
Code.
2.1.2 Intake Combustion Air
The combustion air can be taken through the
wall, or through the roof. When taken from the wall, it
must be taken from out-of-doors by means of the Laars
horizontal wall terminal (see Table 2). When taken
from the roof, a eld-supplied rain cap or an elbow
arrangement must be used to prevent entry of rain
water (see Figure 2).
Use single-wall galvanized pipe, per Table
4, for the combustion air intake (see Table 2 for
appropriate size). Route the intake to the heater as
directly as possible. Seal all joints with tape. Provide
adequate hangers. The unit must not support the
weight of the combustion air intake pipe. Maximum
linear pipe length allowed is 50 feet (15.2m). Three
elbows have been calculated into the 50-foot (15.2m)
Size
Each Opening*
Square inches Square cm
500 125 807
750 188 1213
1000 250 1613
1250 313 2020
1500 375 2420
1750 438 2826
2000 500 3226
*Net Free Area in Square Inches / Square cm
Area indicated is for one of two openings; one at oor level
and one at the ceiling, so the total net free area could be
double the gures indicated.
This chart is for use when communicating directly with the
outdoors. For special conditions and alternate methods, refer
to the latest edition of ANSI Z223.1.
Note: Check with louver manufacturers for net free area of
louvers. Correct for screen resistance to the net free area
if a screen is installed. Check all local codes applicable to
combustion air.
Table 3. Combustion Air Openings.

LAARS Heating Systems
Page 8
linear run. Subtract 10 allowable linear feet (3.0m) for
every additional elbow used (see Table 2). When fewer
than 3 elbows are used, the maximum linear pipe
length allowed is still 50 feet (15.2m).
The connection for the intake air pipe is on the
lter box. Pennant appliances may have venting and
combustion air ducting attached to the top or the back.
They are shipped with the connections at the top. For
attaching either or both pipes to the back, the mounting
anges are reversible by removing the mounting
screws and orienting the anges in the desired
position. Replace the screws after positioning anges.
Run a bead of silicone around the collar and slide the
pipe over the collar. Secure with sheet metal screws.
In addition to air needed for combustion, air
shall also be supplied for ventilation, including all air
required for comfort and proper working conditions
for personnel. The Pennant loses less than 1 percent of
its input rating to the room, but other heat sources may
be present.
2.2 Venting
2.2.1 Vent Categories
Depending upon desired Pennant venting, it may
be considered a Category I or a Category III appliance.
In general, a vertical vent system will be a Category
I system. However, in rare instances, a Pennant’s
vertical vent system may be considered Category
III. In the U.S., the National Fuel Gas Code (ANSI
Z223.1), or in Canada the Natural Gas and Propane
Installation Code (CSA B149.1), denes a Category I
vent system, and includes rules and tables to size these
vent systems. If the Pennant’s vertical vent system
does not satisfy the criteria for Category I venting, it
must be vented as a Category III system.
All Pennant vent systems which discharge
horizontally (without the use of a power venter) are
considered Category III vent systems.
2.2.2 Category I Vent
When vented as a Category I appliance, the
vent system must conform to the National Fuel Gas
Code (ANSI Z223.1-Latest Edition) in the U.S., or in
Canada, to the Natural Gas and Propane Installation
Code (CSA B149.1 latest edition). The vent system
must be sized and installed for a Category I Fan-
Assisted Appliance.
If chimney height is greater than 25 feet, or
if multiple units are vented into the same vertical
vent, a barometric damper must be installed on each
appliance, such that the ue draft does not exceed
(negative) 0.1 in. w.c.
If using a power venter for any type of Category
I venting, the draft should be set between (negative)
0.01 and 0.05 in. w.c.
2.2.3 Common Venting Systems
Pennant units are Category I fan-assisted when
vented vertically and adhering to all applicable codes.
Pennant units are not allowed to be vented into a
common horizontal vent system, unless a properly
sized vent fan is used, and the common vent system
is properly designed by the vent fan manufacturer or
a qualied engineer. When common venting Pennant
fan-assisted unit with other appliances through
one shared vertical duct called a “common vent”,
special care must be taken by the installer to ensure
safe operation. In the event that the common vent
is blocked, it is possible, especially for fan-assisted
devices, to vent backwards through non-operating
appliances sharing the vent, allowing combustion
products to inltrate occupied spaces. If the
appliances are allowed to operate in this condition,
serious injury or death may occur.
WARNING
Operation of appliances with a blocked common
vent may lead to serious injury or death. Safety
devices must be implemented to prevent blocked
common vent operation. If safe operation of all
appliances connected to a common vent cannot
be assured, including prevention of spillage of flue
gasses into living spaces, common venting should
not be applied, and appliances should each be
vented separately.
Figure 2. Combustion Air and Vent Through Roof.
Term Description
Pipe Single-wall galvanized steel pipe, 24 gauge
minimum (either insulated or non-insulated)
Joint Sealing Permanent duct tape or aluminum tape
Table 4. Required Combustion Air Piping Material.

Low Temperature Pennant Page 9
AVERTISSEMENT
Le fonctionnement d’appareils connectés à un
évent commun bouché peut provoquer de sérieuses
blessures corporelles ou la mort. Des dispositifs de
sécurité doivent être mis en place pour empêcher
que les appareils soient utilisés avec un évent
commun bouché. Si un fonctionnement sécuritaire
de tous les appareils reliés à un évent commun et si
la prévention des dégagements accidentels de gaz
de combustion dans des zones habitées ne peuvent
pas être assurés, un évent commun ne doit pas
être mis en place et les appareils doivent être munis
d’évents individuels séparés.
It is for this reason that, in addition to
following proper vent sizing, construction and safety
requirements from the National Fuel Gas Code,
ANSI Z223.1 or in Canada, from the Natural Gas and
Propane Installation Code (CSA B149.1) as well as
all applicable local codes, it is required that installers
provide some means to prevent operation with a
blocked common vent. It is suggested that a blocked
vent safety system be employed such that if the switch
from one appliance trips due to excessive stack spill
or back pressure indicating a blocked vent condition,
that all appliances attached to the vent be locked out
and prevented from operating. Note that the Pennant
is equipped with a blocked vent safety (pressure)
switch, as shipped. However, this safety switch has
only been designed and tested to be effective in
installations where the Pennant is vented separately
and NOT common vented with other appliances. As an
additional precaution, it is recommended that a Carbon
Monoxide (CO) alarm be installed in all enclosed
spaces containing combustion appliances. If assistance
is required in determining how a blocked vent safety
system should be connected to a LAARS product,
please call Applications Engineering at the Rochester
phone number on the back cover of this manual.
Refer to the installation and operating
instructions on all appliances to be common vented
for instructions, warnings, restrictions and safety
requirements. If safe operation of all appliances
connected to a common vent cannot be assured,
including prevention of spillage of ue gases into
living spaces, common venting should not be applied,
and appliances should each be vented separately.
2.2.4 Category III Vent
When the Pennant is vented with horizontal
discharge, it must be installed per this installation
manual and the venting system manufacturer’s
installation instructions. The vent system must be
sealed stainless steel, per Table 5.
Route the vent pipe to the heater as directly as
possible. Seal all joints and provide adequate hangers
as required in the venting system manufacturer’s
installation instructions. Horizontal portions of the
venting system must be supported to prevent sagging
and may not have any low sections that could trap
condensate.
The unit must not support the weight of the vent
pipe. Horizontal runs must slope downwards not less
than ¼ inch per foot (2 cm/m) from the unit to the vent
terminal.
L’appareil ne doit pas supporter le poids de la
gaine d’évent. Les parties horizontales doivent être
installées avec une pente de 2 cm/m (1/4 inch par pied)
descendant de l’appareil vers la sortie de l’évent.
Reference Table 2 for the size of the Category
III vent system. Up to three elbows can be used with
50 linear feet (15.2m) of pipe. Subtract 10 allowable
linear feet (3.0m) for every additional elbow used.
2.3 Locating Vent & Combustion Air
Terminals
2.3.1 Side Wall Vent Terminal
The appropriate Laars side wall vent terminal
must be used, and is listed in the installation and
operation manual. The terminal provides a means of
installing the vent piping through the building wall,
and must be located in accordance with ANSI Z223.1/
NFPA 54 and applicable local codes. In Canada, the
installation must be in accordance with CSA B149.1
and local applicable codes. Consider the following
when installing the terminal:
1. Figure 3 shows the requirements for mechanical
vent terminal clearances for the U.S. and Canada.
2. Locate the vent terminal so that vent gases cannot
be drawn into air conditioning system inlets.
3. Locate the vent terminal so that vent gases cannot
enter the building through doors, windows,
gravity inlets or other openings. Whenever
possible, locations under windows or near doors
should be avoided.
4. Locate the vent terminal so that it cannot be
blocked by snow. The installer may determine
that a vent terminal must be higher than the
minimum shown in codes, depending upon local
conditions.
5. Locate the terminal so the vent exhaust does
not settle on building surfaces or other nearby
objects. Vent products may damage such surfaces
or objects.
6. If the boiler or water heater uses ducted
combustion air from an intake terminal located
on the same wall, locate the vent terminal at least
Term Description
Pipe Must comply with UL Standard 1738 such
as Type AL29-4C Stainless Steel
(either insulated or non-insulated).
Joint
Sealing
Follow vent manufacturer's instructions.
Table 5. Required Horizontal Venting Material.

LAARS Heating Systems
Page 10
U.S. Installations (see note 1) Canadian Installations (see note 2)
A= Clearance above grade, veranda, porch, 12 inches (30 cm) 12 inches (30 cm)
deck, or balcony
B= Clearance to window or door that may Direct Vent Only: 12 inches (30 cm)
be opened Other Than Direct Vent: 4 feet (1.2 m) below or 36 inches (91 cm)
to side of opening; 1 foot (30 cm) above opening
C= Clearance to permanently closed window See note 4 See note 5
D= Vertical clearance to ventilated soffit located
above the terminal within a horizontal See note 4 See note 5
distance of 2 feet (61cm) from the center line of the terminal
E= Clearance to unventilated soffit See note 4 See note 5
F= Clearance to outside corner See note 4 See note 5
G= Clearance to inside corner See note 4 See note 5
H= Clearance to each side of center line See note 4 3 feet (91 cm) within a height 15 feet
extended above meter/regulator assembly above the meter/regulator assembly
I= Clearance to service regulator vent outlet See note 4 3 feet (91 cm)
J= Clearance to non mechanical air supply Direct Vent Only: 12 inches (30 cm)
inlet to building or the combustion air inlet Other Than Direct Vent: 4 feet (1.2 m) below or 36 inches (91 cm)
to any other appliance to side of opening; 1 foot (30 cm) above opening
K= Clearance to a mechanical air supply inlet 3 feet (91 cm) above if within 10 feet (3 m) 6 feet (1.83 m)
horizontally
L= Clearance above paved sidewalk or paved Vent termination not allowed in this location Vent termination not allowed in this
driveway located on public property location
M= Clearance under veranda, porch, deck, See note 4 12 inches (30 cm) (see note 3)
or balcony
Notes:
1. In accordance with the current ANSI Z223.1 / NFPA 54 National Fuel Gas Code.
2. In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code.
3. Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.
4. For clearances not specified in ANSI Z223.1 / NFPA 54, clearance is in accordance with local installation codes and the requirements of
the gas supplier.
5. For clearances not specified in CSA B149.1, clearance is in accordance with local installation codes and the requirements of the gas
supplier.
Figure 3. Vent Terminal Clearances.

Low Temperature Pennant Page 11
3 feet (0.9m) horizontally from the combustion
air terminal, and locate the vent terminal at least
1 foot (0.3m) above the combustion air terminal.
WARNING
The outdoor vent terminal gets hot. Unit must be
installed in such a way as to reduce the risk of
burns from contact with the vent terminal.
AVERTISSEMENT
La sortie d’évent à l’extérieur devient très chaude.
Elle doit être installée de façon à réduire le risque
de brûlures au contact de l’extrémité de l’évent.
Important Note: Massachusetts Code Requirement.
From Massachusetts Rules and Regulations 248
CMR 5.08:
(a) For all side wall horizontally vented gas
fueled equipment installed in every dwelling,
building or structure used in whole or in
part for residential purposes, including those
owned or operated by the Commonwealth and
where the side wall exhaust vent termination
is less than seven (7) feet above nished grade
in the area of the venting, including but not
limited to decks and porches, the following
requirements shall be satised:
1. INSTALLATION OF CARBON MONOXIDE
DETECTORS.
At the time of installation of the side wall
horizontal vented gas fueled equipment, the
installing plumber or gastter shall observe that
a hard-wired carbon monoxide detector with
an alarm and battery back-up is installed on
the oor level where the gas equipment is to be
installed. In addition, the installing plumber or
gastter shall observe that a battery operated or
hard-wired carbon monoxide detector with an
alarm is installed on each additional level of the
dwelling, building or structure served by the side
wall horizontal vented gas fueled equipment.
It shall be the responsibility of the property
owner to secure the services of qualied licensed
professionals for the installation of hard-wired
carbon monoxide detectors.
a. In the event that the side wall
horizontally vented gas fueled equipment
is installed in a crawl space or an attic, the
hard-wired carbon monoxide detector with
alarm and battery back-up may be installed
on the next adjacent oor level.
b. In the event that the requirements of
this subdivision cannot be met at the time of
completion of installation, the owner shall
have a period of thirty (30) days to comply
with the above requirements; provided,
however, that during said thirty (30) day
period, a battery operated carbon monoxide
detector with an alarm shall be installed.
2. APPROVED CARBON MONOXIDE
DETECTORS.
Each carbon monoxide detector as required
in accordance with the above provisions shall
comply with NFPA 720 and be ANSI/UL 2034
listed and IAS certied.
3. SIGNAGE.
A metal or plastic identication plate shall be
permanently mounted to the exterior of the
building at a minimum height of eight (8) feet
above grade directly in line with the exhaust vent
terminal for the horizontally vented gas fueled
heating appliance or equipment. The sign shall
read, in print size no less than one-half (½) inch
in size, “GAS VENT DIRECTLY BELOW.
KEEP CLEAR OF ALL OBSTRUCTIONS”.
4. INSPECTION.
The state or local gas inspector of the side
wall horizontally vented gas fueled equipment
shall not approve the installation unless, upon
inspection, the inspector observes carbon
monoxide detectors and signage installed in
accordance with the provisions of 248 CMR
5.08(2)(a) 1 through 4.
(b) EXEMPTIONS: The following equipment is
exempt from 248 CMR 5.08(2)(a) 1 through 4:
1. The equipment listed in Chapter 10 entitled
“Equipment Not Required To Be Vented” in the
most current edition of NFPA 54 as adopted by
the Board; and
2. Product Approved side wall horizontal vented gas
fueled equipment installed in a room or structure
separate from the dwelling, building or structure
used in whole or in part for residential purposes.
(c) MANUFACTURER REQUIREMENTS –
GAS EQUIPMENT VENTING SYSTEM
PROVIDED. When the manufacturer of
Product Approved side wall horizontally
vented gas equipment provides a venting
system design or venting system components
with the equipment, the instructions provided
by the manufacturer for installation of the
equipment and the venting system shall
include:
1. Detailed instructions for the installation of the
venting system design or the venting system
components; and
2. A complete parts list for the venting system

LAARS Heating Systems
Page 12
design or venting system.
(d) MANUFACTURER REQUIREMENTS –
GAS EQUIPMENT VENTING SYSTEM
NOT PROVIDED. When the manufacturer
of a Product Approved side wall horizontally
vented gas fueled equipment does not
provide the parts for venting the fuel gases,
but identies “special venting systems”, the
following requirements shall be satised by
the manufacturer:
1. The referenced “special venting system”
instructions shall be included with the appliance
or equipment installation instructions; and
2. The “special venting systems” shall be Product
Approved by the Board, and the instructions for
that system shall include a parts list and detailed
installation instructions.
(e) A copy of all installation instructions for all
Product Approved side wall horizontally
vented gas fueled equipment, all venting
instructions, all parts lists for venting
instructions, and/or all venting design
instructions shall remain with the appliance
or equipment at the completion of the
installation.
2.3.2 Side Wall Combustion Air Terminal
The Laars side wall combustion air terminal
(listed in Table 2) must be used when the unit takes
its combustion air through a duct from a side wall.
Consider the following when installing the terminal:
1. Do not locate the air inlet terminal near a source
of corrosive chemical fumes (e.g., cleaning uid,
chlorinated compounds, etc.)
2. Locate the terminal so that it will not be subject
to damage by accident or vandalism.
3. Locate the combustion air terminal so that it
cannot be blocked by snow. The National Fuel
Gas Code requires that it be at least 12 inches (30
cm) above grade, but the installer may determine
it should be higher, depending upon local
conditions.
4. If the Pennant is side-wall vented to the same
wall, locate the vent terminal at least 3 feet
(0.9m) horizontally from the combustion air
terminal, and locate the vent terminal at least 1
foot (0.3m) above the combustion air terminal
(see Figure 3).
2.3.3 Vertical Vent Terminal
When the unit is vented through the roof, the
vent must extend at least 3 feet (0.9m) above the point
at which it penetrates the roof. It must extend at least
2 feet (0.6m) higher than any portion of a building
within a horizontal distance of 10 feet (3.0m), and high
enough above the roof line to prevent blockage from
snow. When the combustion air is taken from the roof,
the combustion air must terminate at least 12" (30cm)
below the vent terminal (see Figure 2).
2.3.4 Vertical Combustion Air Terminal
When combustion air is taken from the roof, a
eld-supplied rain cap or an elbow arrangement must
be used to prevent entry of rain water (see Figure 2).
The opening on the end of the terminal must be at least
12" (30cm) above the point at which it penetrates the
roof, and high enough above the roof line to prevent
blockage from snow. When the vent terminates on the
roof, the combustion air must terminate at least 12"
(30cm) below the vent terminal.
2.4 Common Vent Test — Boilers
When an existing boiler is removed from a
common venting system, the common venting system
is likely to be too large for proper venting of the
appliances remaining connected to it.
At the time of removal of an existing boiler, the
following steps shall be followed with each appliance
remaining connected to the common venting system
placed in operation, while the other appliances
remaining connected to the common venting system
are not in operation.
1. Seal any unused openings in the common venting
system.
2. Visually inspect the venting system for proper
size and horizontal pitch and determine there is
non blockage or restriction, leakage, corrosion
and other deciencies which could cause an
unsafe condition.
3. Insofar as it is practical, close all building doors
and windows and all doors between the space in
which the appliances remaining connected to the
common venting system are located and other
spaces of the building. Turn on clothes dryers
and any appliance not connected to the common
venting system. Turn on any exhaust fans, such
as range hoods and bathroom exhausts, so they
will operate at maximum speed. Do not operate a
summer exhaust fan. Close replace dampers.
4. Place in operation the appliance being
inspected. Follow the lighting instructions.
Adjust thermostat so appliance will operate
continuously.
5. Test for spillage at the draft hood relief opening
after 5 minutes of main burner operation. Use
the ame of a match or candle, or smoke from a
cigarette, cigar or pipe.
6. After it has been determined that each appliance
remaining connected to the common venting
system properly vents when tested as outlined
above, return doors, windows, exhaust fans,
replace dampers and any other gas burning
appliance to their previous conditions of use.
7. Any improper operation of the common venting
system should be corrected so that the installation

Low Temperature Pennant Page 13
conforms with the National Fuel Gas Code,
ANSI Z223.1/NFPA 54 and/or CSA B149.1,
Natural Gas and Propane Installation Codes.
When resizing any portion of the common
venting system, the common venting system
should be resized to approach the minimum size
as determined using the appropriate tables in
Appendix F in the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 and/or CSA B149.1, Natural
Gas and Propane Installation Codes.
2.4 Véricationdeséventscommuns—
Chaudières
Lorsqu’une chaudière existante est déconnectée
du réseau d’évents commun, ce réseau d’évents
commun devient probablement trop grand pour
les appareils qui lui restent connectés. Lorsqu’une
chaudière existante est retirée, les étapes suivantes
doivent être accomplies pour chaque appareil qui
reste connecté au réseau d’évents commun utilisé,
alors que les autres appareils qui sont encore
connectés au réseau commun d’évents ne sont pas en
fonctionnement.:
1. Sceller toutes les ouvertures non utilisées du
système d'évacuation.
2. Inspecter de façon visuelle le système
d'évacuation pour déterminer la grosseur et
l'inclinaison horizontale qui conviennent et
s'assurer que le système est exempt d'obstruction,
d'étranglement, de fuite, de corrosion et autres
défaillances qui pourraient présenter des risques.
3. Dans la mesure du possible, fermer toutes les
portes et les fenêtres du bâtiment et toutes les
portes entre l'espace où les appareils toujours
raccordés au système d'évacuation sont installés
et les autres espaces du bâtiment. Mettre en
marche les sécheuses, tous les appareils non
raccordés au système d'évacuation common
et tous les ventilateurs d'extraction comme
les hottes de cuisinière et les ventilateurs des
salles de bain. S'assurer que ces ventilateurs
fonctionnent à la vitesse maximale. Ne pas faire
fonctionner les ventilateurs d'été. Fermer les
registres des cheminées.
4. Mettre l'appareil inspecté en marche. Suivre les
instructions d'allumage. Réegler le thermostat de
façon continue.
5. Faire fonctionner le brûleur principal pendant
5 min ensuite, déterminer si le coupe-tirage
déborde à l'ouverture de décharge. Utiliser la
amme d'une allumette ou d'une chandelle ou la
fumée d'une cigarette, d'un cigare ou d'une pipe.
6. Une fois qu'il a été déterminé, selon la méthode
indiquée ci-dessus, que chaque appareil
raccordé au système d'évacuation est mis à l'air
libre de façon adéquate. Remettre les portes
et les fenêtres, les ventilateurs, les registres de
cheminées et les appareils au gaz à leur position
originale.
7. Tout mauvais fonctionnement du système
d'évacuation commun devrait être corrigé
de façon que l'installation soit conforme au
National Fuel Gas Code, ANSI Z223.1/NFPA
54 et (ou) aux codes d'installation CSA-B149.1.
Si la grosseur d'une section du système devrait
être modié, le système devrait être modié pour
respecter les valeurs minimales des tableaux
pertinents de l'appendice F du National Fuel Gas
Code, ANSI Z223.1/NFPA 54 et (ou) les codes
d'installation CSA-B149.1
2.5 Vent Terminals for Outdoor Units
For outdoor applications, the vent and
combustion air openings must be covered with proper
terminals to prevent rain, snow and other objects from
falling into the Pennant.
If local codes allow, outdoor installations may
use 1' (one foot) of appropriately sized galvanized
single wall or type "B" vent and a rain cap for exhaust
vent termination in the default conguration (venting
out of the top). An appropriately sized 90° elbow,
positioned with the opening facing down, may be used
on the combustion air inlet in the default conguration
on the back of the unit. Note that some local codes
may require a higher vertical vent height, extending
above any perimeter fencing, etc. In installations
where the appearance of the vent is objectionable, the
low prole vent terminals listed in Table 6 may be
used.
Part numbers for the low prole terminals to
cover the vent and combustions air openings are
shown in Table 6.
Size Outdoor
Vent
Terminal
Outdoor
Combustion
Air Terminal
500 20254703 D2007900
750 20254705 D2007900
1000 20254705 D2008000
1250 D2007700 D2008000
1500 D2007700 D2008000
1750 D2007800 D2008000
2000 D2007800 D2008200
Table 6. Vent Terminals for Outdoor Units.

LAARS Heating Systems
Page 14
SECTION 3.
Gas Supply and Piping
3.1 Gas Supply and Piping
Gas piping should be supported by suitable
hangers or oor stands, not by the appliance.
The Pennant’s gas train allows the user to pipe
the gas from either the right side or the left side of
the unit. As shipped, the right side of the gas train is
capped off, and there is a manual valve on the left side.
If desired, the manual valve on the left side of the gas
train may be moved to the right side, and the cap on
the right side may be moved to the left.
Review the following instructions before
proceeding with the installation.
1. Verify that the appliance is tted for the proper
type of gas by checking the rating plate. Pennant
appliances are equipped to operate at elevations
up to 10,000 feet (3050m). Pennant appliances
may be adjusted to operate properly at altitudes
above 2500 feet (see Section 6.5.2) and the input
will be reduced if the heating value of the gas
supply is below sea level values.
2. The maximum inlet gas pressure must not
exceed 13" w.c. (3.2kPa). The minimum inlet gas
pressure is 5 in. w.c. (1.2 kPa).
3. Refer to Table 7, size supply.
4. Run gas supply line in accordance with all
applicable codes.
5. Locate and install manual shutoff valves in
accordance with state and local requirements.
6. A sediment trap must be provided upstream of
the gas controls.
7. All threaded joints should be coated with
piping compound resistant to action of liqueed
petroleum gas.
8. The appliance and its individual shutoff valve
must be disconnected from the gas supply piping
during any pressure testing of that system at test
pressures in excess of 0.5 psig (3.45 kpa).
9. The unit must be isolated from the gas supply
system by closing its individual manual shutoff
valve during any pressure testing of the gas
supply piping system at test pressures equal to or
less than 0.5 psig (3.45 kpa).
10. The appliance and its gas connection must be
leak tested before placing it in operation.
11. Purge all air from gas lines.
WARNING
Do not use open flame to check for leaks. An open
flame could lead to explosion, which could result in
property damage, serious injury or death.
AVERTISSEMENT
Ne recherchez pas les fuites avec une flamme nue.
Une flamme nue peut provoquer une explosion qui
peut causer des dommages matériels, de sérieuses
blessures corporelles ou la mort.
NOTE: The Pennant appliance and all other gas
appliances sharing the gas supply line must be firing
at maximum capacity to properly measure the inlet
supply pressure. The pressure can be measured at
the supply pressure port on the gas valve. Low gas
pressure could be an indication of an undersized
gas meter, undersized gas supply lines and/or an
obstructed gas supply line.
Distance from Gas Meter or Last Stage Regulator
Size and
Gas Type 0-100' 0-31 m 100-200' 31-61m 200-300' 61-91m
500 natural 1½" 3.8 cm 2" 5.1 cm 2" 5.1 cm
500 propane 1" 2.5 cm 1½" 3.8 cm 1½" 3.8 cm
750 natural 2" 5.1 cm 2" 5.1 cm 2½" 6.4 cm
750 propane 1½" 3.8 cm 1½" 3.8 cm 2" 5.1 cm
1000 natural 2" 5.1 cm 2½" 6.4 cm 3" 7.6 cm
1000 propane 1½" 3.8 cm 2" 5.1 cm 2½" 6.4 cm
1250 natural 2½" 6.4 cm 2½" 6.4 cm 3" 7.6 cm
1250 propane 2" 5.1 cm 2" 5.1 cm 2½" 6.4 cm
1500 natural 2½" 6.4 cm 3" 7.6 cm 3" 7.6 cm
1500 propane 2" 5.1 cm 2½" 6.4 cm 2½" 6.4 cm
1750 natural 2½" 6.4 cm 3" 7.6 cm 3" 7.6 cm
1750 propane 2" 5.1 cm 2½" 6.4 cm 2½" 6.4 cm
2000 natural 3" 7.6 cm 3" 7.6 cm 3½" 8.9 cm
2000 propane 2½" 6.4 cm 2½" 6.4 cm 3" 7.6 cm
Notes:
1. These gures are based on 1/2" (0.12 kPa) water column pressure drop.
2. Check supply pressure and local code requirements before proceeding with work.
3. Pipe ttings must be considered when determining gas pipe sizing.
Table 7. Gas Piping Size.

Low Temperature Pennant Page 15
Figure 4. Suggested Piping - Hydronic Boiler.
THERMOMETER
SENSOR
TEMPERATURE
GLOBE VALVE
CHECK VALVE
LEGEND
W/ FAST FILL BYPASS
PRESSURE REDUCING VALVE
WITH AIR SCOOP AND
AUTO AIR VENT
EXPANSION TANK
3-WAY VALVE
Cold Water
Make-Up
VALVE
VALVE
PURGE
PUMP
ADDITIONAL REQUIREMENTS.
WITH LOCAL CODES AND ORDINANCES FOR
PIPING CONFIGURATION AND VALVING, CHECK
WARNING: THIS DRAWING SHOWS SUGGESTED
Pump
System
Supply
System
System
Return
C
INSTALL AIR VENTS AT HIGH POINTS IN SYSTEM.
PIPING&SIZING OF EXPANSION TANK
PER TANK MANUFACTURER'S INSTRUCTIONS.
PRIMARY/SECONDARY MANDATORY FOR ALL
VARIABLE FLOW SYSTEMS.
BOILER WATER CONNECTIONS (INLET/OUTLET)
MAYVARY. VERIFY CONNECTION ORIENTATION.
BOILER CIRCUIT PIPING MUST BE EQUAL
BOILER WATER CONNECTION SIZE.
DIMENSION "C" TO BE4PIPE DIAMETERS.
DOTTED DEVICES INDICATE ALTERNATE
LOCATIONS.
TEMPERATURE SENSORS REQUIRE FIELD
INTERLOCK TO BOILER CONTROLS.
COMBINED FLOW OF ALL BOILERS.
COMMON PIPING MUST BE SIZED FOR
BOILER CIRC. PUMP SIZED FOR FLOW
THROUGH BOILER
FULL-SIZED PIPING.
AND 30 FEET OF
MINIMUM INLET WATER TEMP = 70°F
3-Way Valve
Mounted on Pennant
Pump Mounted
on Pennant
C
Figure 5. Hydronic Piping — One Boiler, Multi-Temperature System.
THERMOMETER
SENSOR
TEMPERATURE
GLOBE VALVE
CHECK VALVE
W/ FAST FILL BYPASS
PRESSURE REDUCING VALVE
WITH AIR SCOOP AND
AUTO AIR VENT
EXPANSION TANK
3-WAY VALVE
VALVE
VALVE
PURGE
PUMP
ADDITIONAL REQUIREMENTS.
WITH LOCAL CODES AND ORDINANCES FOR
PIPING CONFIGURATION AND VALVING, CHECK
WARNING: THIS DRAWING SHOWS SUGGESTED
INSTALL AIR VENTS AT HIGH POINTS IN SYSTEM.
PIPING&SIZING OF EXPANSION TANK
PER TANK MANUFACTURER'S INSTRUCTIONS.
PRIMARY/SECONDARY MANDATORY FOR ALL
VARIABLE FLOW SYSTEMS.
BOILER WATER CONNECTIONS (INLET/OUTLET)
MAYVARY. VERIFY CONNECTION ORIENTATION.
BOILER CIRCUIT PIPING MUST BE EQUAL
BOILER WATER CONNECTION SIZE.
DIMENSION "C" TO BE4PIPE DIAMETERS.
DOTTED DEVICES INDICATE ALTERNATE
LOCATIONS.
TEMPERATURE SENSORS REQUIRE FIELD
INTERLOCK TO BOILER CONTROLS.
COMBINED FLOW OF ALL BOILERS.
COMMON PIPING MUST BE SIZED FOR
BOILER CIRC. PUMP SIZED FOR FLOW THROUGH
BOILER AND 30 FEET OF FULL-SIZED PIPING.
MINIMUM INLET WATER TEMP = 70°F
LEGEND
Cold Water
Make-Up
Pump
System
Supply
System
System
Return
C
3-Way Valve
Mounted on Pennant
Pump Mounted
on Pennant

LAARS Heating Systems
Page 16
Size 20°F (11°C) 25°F (14°C) 30°F (17°C) 35°F (19°C)
gpm lpm gpm lpm gpm lpm gpm lpm
500 43 161 34 129 26 107 24 92
750 64 241 51 193 43 161 36 138
1000 85 321 68 257 57 214 49 184
1250 106 401 85 322 71 269 61 231
1500 128 483 102 386 85 322 73 276
1750 N/R N/R 119 451 99 375 85 322
2000 N/R N/R 103 515 113 429 97 368
Notes: gpm = gallons per minute, lpm = liters per minute,
Maximum temperature rise is 35°F (19°C), as shown.
N/R = not recommended.
Table 8. Temperature Rise - Boiler.
SECTION 4A.
Water Connections —
Pennant Boiler
4A.1 Heating System Piping:
Hot Supply Connections — Boiler
NOTE: This appliance must be installed in a closed
pressure system with a minimum of 12 psig (82.7
kPa) static pressure at the boiler.
Hot water piping should be supported by suitable
hangers or oor stands. Do not support piping with
this appliance. Due to expansion and contraction of
copper pipe, consideration should be given to the type
of hangers used. Rigid hangers may transmit noise
through the system resulting from the piping sliding in
the hangers. It is recommended that padding be used
when rigid hangers are installed. Maintain 1" clearance
to combustibles for hot water pipes.
Pipe the discharge of the relief valve (full size)
to a drain or in a manner to prevent injury in the event
of pressure relief. Install an air purger, an air vent,
a diaphragm-type expansion tank, and a hydronic
ow check in the system supply loop. Minimum ll
pressure must be 12 psig (82.7 kPa). Install shutoff
valves where required by code.
See suggested piping diagrams (Figures 4-5).
These diagrams are meant only as a guide. Com pon-
ents required by local codes must be properly installed.
Note the recommended location of the
temperature sensor on the diagrams; you must provide
a location for the additional sensor shipped with the
Pennant. This sensor may be strapped onto pipe from
1" to 4" diameter, or inserted into an immersion well.
4A.2 Cold Water Make-Up — Boiler
1. Connect the cold water supply to the inlet
connection of an automatic ll valve.
2. Install a suitable back ow preventer between the
automatic ll valve and the cold water supply.
3. Install shut off valves where required.
NOTE: The boiler, when used in connection with a
refrigeration system, must be installed so the chilled
medium is piped in parallel with the boiler with
appropriate valves to prevent the chilled medium from
entering the boiler.
The boiler piping system of a hot water heating
boiler connected to heating coils located in air
handling appliances where they may be exposed to
refrigerated air circulation must be equipped with ow
control valves or other automatic means to prevent
gravity circulation of the boiler water during the
cooling cycle.
A boiler installed above radiation level, or as
required by the authority having jurisdiction, must be
provided with a low water cutoff device either as a part
of the boiler or at the time of boiler installation.
4A.3 Water Flow Requirements — Boiler
Low Temperature Pennant Boilers are equipped
with a mounted pump. The pumps are sized for the
boiler’s head loss and 30 feet of full-size piping (same
size as boiler outlet), with a normal number of ttings.
The boilers must be piped in a primary-secondary sys-
tem, such that the boiler’s pump only serves the boiler.
Figures 4 and 5 show examples of this type of piping.
The minimum inlet water temperature to the
Pennant is 70°F (20°C). The mixing system on the
Pennant will ensure that the heat exchanger in the
Pennant does not see water that is less than 120°F
(49°C), so that excessive condensation does not form
on the heat exchanger.
Table 8 shows a relationship between water ow
through the boiler and the temperature difference (rise)
between the inlet and outlet of the boiler. This table
will enable the user to test the boiler for proper water
ow. Since the boiler has a mixing system that sends
a portion of the hot water from the boiler outlet to the
boiler inlet, the water ow coming out of the mixing
system will vary, depending on the return water
temperature.
4A.4 Freeze Protection — Boiler
Boiler installations are not recommended in
areas where the danger of freezing exists unless proper
precautions are made for freeze protection. A non
toxic, heating system, anti-freeze may be added to the
hydronic system provided that the concentration does
not exceed 50% and the anti freeze contains an anti
foamant. Power outage, interruption of gas supply,
failure of system components, activation of safety
devices, etc., may prevent a boiler from ring. Any
time a boiler is subjected to freezing conditions,
and the boiler is not able to re, and/or the water
is not able to circulate, there is a risk of freezing in
the boiler or in the pipes in the system. When water
freezes, it expands. This can result in bursting of pipes
in the system, or damage to the boiler, which could
result in leaking or ooding conditions.
IMPORTANT NOTES: Different glycol products may
provide varying degrees of protection. Glycol products
must be maintained properly in a heating system, or
they may become ineffective. Consult the glycol speci-
fications, or the glycol manufacturer, for information
about specific products, maintenance of solutions, and
set up according to your particular conditions. Never
use ethylene glycol (automotive antifreeze).

Low Temperature Pennant Page 17
SECTION 4B.
Water Connections —
Pennant Water Heater
4B.1 Water System Piping —
Water Heater
Hot water piping should be supported by suitable
hangers or oor stands. Do not support piping with
this appliance. Due to expansion and contraction of
copper pipe, consideration should be given to the type
of hangers used. Rigid hangers may transmit noise
through the system resulting from the piping sliding in
the hangers. It is recommended that padding be used
when rigid hangers are installed.
The Pennant can be used with several different
types of readily available storage tanks. Pennant units
have a circulating pump built into the water heater.
The pumps used are sized for the head loss through the
heater, plus 30 feet (9.1 m) of full-sized piping (same
size as boiler outlet) and a normal number of ttings.
Pumps used are sized for soft, normal or hard water,
so make sure the unit matches the water quality of the
installation.
Pipe the outlet from the heater’s relief valve
such that any discharge from the relief valve will be
conducted to a suitable place for disposal when relief
occurs. Do not reduce line size or install any valves in
this line. The line must be installed to allow complete
drainage of both the valve and the line.
Suggested piping diagrams are shown in Figures
6,7,8 and 9. These diagrams are meant only as a guide.
Components required by local codes must be properly
installed.
Note the recommended location of the
temperature sensor on the diagrams. The Pennant is
shipped with an additional sensor that can be used in
the storage tank, in lieu of a separate tank thermostat.
The minimum inlet water temperature for the
Low-Temp Pennant is 70°F (20°C). The mixing
system on the Pennant will ensure that the heat
exchanger in the Pennant does not see water that is
less than 120°F (49°C), so that excessive condensation
does not form on the heat exchanger.
4B.2 Hot Water Supply Piping —
Water Heater
Follow the tank manufacturer’s guidelines for
completion of the hot water system connections.
NOTE: A listed temperature and pressure relief
valve listed as complying with the Standard for
Relief Valves and Automatic Gas Shutoff Devices
for Hot Water Supply Systems (ANSI Z21.22/
CSA 4.4), of suitable discharge capacity must be
installed in the separate storage tank system.
If the Pennant water heater is installed in a closed
water supply system, such as one having a backow
preventer in the cold water supply line, the relief valve
may discharge periodically, due to thermal expansion.
Means (such as a properly-sized expansion tank) shall
be provided to control thermal expansion. Contact the
water supplier or local plumbing inspector on how to
control this situation.
4B.3 Water Flow Requirements —
Water Heater
In a water heating application (an open system),
new water is constantly being introduced. With the
new water comes a fresh supply of minerals that can
be deposited on the unit’s heat exchanger. This is
commonly known as scaling. The amount of minerals
will depend upon the hardness of the water. Water can
also be aggressive, and can erode metals, including
copper, if the water is moved too quickly. The water
ow requirements for the Pennant water heater are
based upon the hardness of the water. The water ow
is kept high enough to prevent scaling, but low enough
to prevent tube erosion. For extremely soft or hard
water, cupro-nickel tubes are available. Contact a
Laars representative if you have questions or concerns
about water quality.
Pennant water heaters are built with a mounted
pump that is sized for soft, normal or hard water. The
pumps used are sized for the head loss through the
heater, plus 30 feet (9.1m) of full-sized piping (same
size as heater outlet) and a normal number of ttings.
Table 9 species water ow rates for water
heaters, which will enable the user to ensure that the
Pennant is getting the correct water ow when it is in
operation.
4B.4 Combined Water Heating (potable)
and Space Heating — Water Heater
NOTE: Combined systems must be allowed by and
installed per local codes.
Piping and components connected to this water
heater for the space heating application shall be
suitable for use with potable water.
Toxic chemicals, such as used for boiler
treatment, shall not be introduced into the potable
water used for space heating.
This water heater when used to supply potable
water shall not be connected to any heating system
or component(s) previously used with a non-potable
water heating appliance.
When the system requires water for heating at
temperatures higher than required for other uses,
an anti-scald mixing or tempering valve shall be
installed to temper the water for those uses in order
to reduce scald hazard potential.
4B.5 Freeze Protection — Water Heater
Although Pennant water heaters are design-

LAARS Heating Systems
Page 18
Figure 6. Suggested Piping — One Water Heater, One Tank.
Table 9. Temperature Rise — Water Heater.
Size GPM Water Flow Temperature Rise °F LPM Water Flow Temperature Rise °C
Soft Normal Hard Soft Normal Hard Soft Normal Hard Soft Normal Hard
500 45 68 90 19 13 9 170 257 341 10 7 5
750 45 68 90 28 19 14 170 257 341 16 10 8
1000 45 68 90 38 25 19 170 257 341 21 14 10
1250 68 68 90 31 31 24 257 257 341 17 17 13
1500 68 68 90 38 38 28 257 257 341 21 21 16
1750 68 68 90 44 44 33 257 257 341 24 24 18
2000 112 112 112 30 30 30 424 424 424 17 17 17
Notes:
Soft Water = 1 to 7.5 grains hardness
Normal Water = 7.6 to 17 grains hardness
Hard Water = more than 17 grains hardness
GPM = gallons per minute
LPM = liters per minute
certied for outdoor installations, such installations
are not recommended in areas subject to freezing
temperatures, unless proper precautions are taken.
Power outage, interruption of gas supply, failure
of system components, activation of safety devices,
etc., may prevent a heater from ring. Any time a
heater is subjected to freezing conditions, and the
heater is not able to re, and/or the water is not
able to circulate, there is a risk of freezing in the
heater or in the pipes in the system. When water
freezes, it expands. This can result in bursting of pipes
in the system, or damage to the heater, which could
result in leaking or ooding conditions.
Contact the local factory representative or Laars
for additional information.

Low Temperature Pennant Page 19
Figure 7. Suggested Piping — Multiple Water Heaters, One Tank.
Figure 8. Suggested Piping — One Water Heater, Multiple Tanks.

LAARS Heating Systems
Page 20
Figure 9. Suggested Piping — Multiple Water Heaters, Multiple Tanks.
SECTION 5.
Electrical Connections
WARNING
The appliance must be electrically grounded in
accordance with the requirements of the authority
having jurisdiction or, in the absence of such
requirements, with the latest edition of the National
Electrical Code, ANSI/NFPA 70, in the U.S. and
with 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
boiler. Plastic pipe or dielectric unions may isolate
the boiler electrically. Service and maintenance
personnel, who work on or around the boiler, may be
standing on wet floors and could be electrocuted by
an ungrounded boiler.
AVERTISSEMENT
L’appareil doit être relié à la terre conformément
aux exigences de la réglementation locale ou,
en l’absence d’une telle réglementation, à la plus
récente édition du National Electrical Code (Code
national de l’électricité) ANSI/NFPA 70 aux États-
Unis, et à la plus récente édition du Code Canadien
de l’électricité 1ère partie (Canadian Electrical
Code Part 1) CSA C22.1, au Canada. N’utilisez
pas les tuyauteries d’eau ou de gaz pour mettre
à la terre les pièces métalliques de la chaudière;
des tuyauteries en plastique ou des raccords
union diélectriques peuvent isoler électriquement
la chaudière. Les employés qui sont appelés à
travailler sur la chaudière ou autour peuvent être
électrocutés par une chaudière qui n’est pas mise à
la terre.