Laars PNCP User manual

Installation and Operation Instructions Document 3164D
H2311900D
Installation and Operation
Instructions for
Pennant™
Pool Heater
Model PNCP
U.S. Reg. 2,765,423
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.
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.
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
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.

LAARS Heating Systems
Page 2
SECTION 1.
General Information
1.1 Introduction..................................................... 3
1.2 Model Identification......................................... 3
1.3 Warranty......................................................... 4
1.4 Dimensions..................................................... 4
1.5 Locating the Appliance ................................... 4
1.6 Locating Heater with Respect to Pool
System Loop................................................... 6
1.7 Locating Appliance for Correct Horizontal Vent/
Ducted Air Distance From Outside Wall ......... 6
SECTION 2.
Venting and Combustion Air
2.1 Combustion Air ............................................... 6
2.1.1 Combustion Air From Room ........................... 6
2.1.2 Intake Combustion Air .................................... 7
2.2 Venting ........................................................... 7
2.2.1 Vent Categories.............................................. 7
2.2.2 Category I Vent............................................... 8
2.2.3 Common Venting Systems ............................. 8
2.2.4 Category III Vent............................................. 8
2.3 Locating Vent & Combustion Air Terminals .... 8
2.3.1 Side Wall Vent Terminal ................................. 8
2.3.2 Side Wall Combustion Air Terminal................ 9
2.3.3 Vertical Vent Terminal .................................. 10
2.3.4 Vertical Combustion Air Terminal ................. 10
2.4 Vent Terminals for Outdoor Units ................. 10
SECTION 3.
Gas Supply and Piping
3.1 Gas Supply and Piping ................................. 11
SECTION 4A.
Water Connections
4.1 Piping ........................................................... 12
4.2 Automatic Chlorinators ................................. 13
4.3 Sensor Locations.......................................... 13
SECTION 5.
Electrical Connections
5.1 Main Power................................................... 13
5.1.1 Sizes 500-1500 ............................................ 13
5.1.2 Sizes 1750-2000 .......................................... 13
5.1.3 Separate Pump Circuit ................................. 13
5.1.4 Auxiliary Time Clock Wiring.......................... 14
5.1.5 All Sizes........................................................ 14
5.2 Temperature (Operating) Control ................. 14
5.3 Programming the Temperature Control........ 14
5.3.1 Temperature Control Overview .................... 14
5.3.2 Programming Control Parameters................ 14
5.3.3 Setpoint - LSP .............................................. 15
5.3.4 Differential - dLS........................................... 16
5.3.5 Pump Operation ........................................... 16
5.3.6 Heater Purge (Pump Delay) - PD ................. 16
5.4 Limit Controls................................................ 16
SECTION 6.
Operating Instructions
6.1 Sequence of Operation................................. 16
6.2 Filling the Heater System ............................. 17
6.3 Operating the Burner and Set Up ................. 17
6.3.1 Set Up for 0 to 2500 Feet Altitude ................ 17
6.3.2 High Altitude Adjustment and Set Up ........... 18
6.4 Shutting Down the Pennant.......................... 18
6.5 Backwash Switch Operation......................... 18
6.6 Spring and Fall Operation
Stand-by Service .......................................... 19
6.7 Winter Operation .......................................... 19
6.8 To Restart the Pennant ................................ 19
6.9 Therapeutic Pools (Spas)............................. 19
SECTION 7.
Maintenance
7.1 System Maintenance .................................... 20
7.2 Appliance Maintenance and
Component Description................................ 20
7.2.1 Burners......................................................... 20
7.2.2 Filter ............................................................. 20
7.2.3 Gas Valves ................................................... 20
7.2.4 Pool Loop High Limit Control........................ 20
7.2.5 Automatic Reset High Limit Control.............. 20
7.2.6 Temperature Control .................................... 21
7.2.7 Ignition Controls............................................ 21
7.2.8 Ignitors.......................................................... 21
7.2.9 Ignition Sensors............................................ 21
7.2.10 Transformer.................................................. 21
7.2.11 Blowers ........................................................ 21
7.2.12 Flow Switch .................................................. 21
7.2.13 Heat Exchanger Coil .................................... 21
SECTION 8.
Trouble Shooting
8.1 Resolving Lockouts ...................................... 22
8.2 Delayed Ignition – Possible Causes ............. 22
8.3 Short Cycling ................................................ 22
8.4 High Gas Consumption ................................ 23
8.5 Troubleshooting the Pool Heater
Temperature Control .................................... 23
8.6 Troubleshooting Pennant Controls ............... 23
SECTION 9.
Replacement Parts
9.1 General Information...................................... 23
9.2 Parts List....................................................... 23
TABLE OF CONTENTS

Pennant Pool Heater Page 3
SECTION 1.
General Information
In the Commonwealth of Massachusetts, this
appliance must be installed by a licensed plumber or
gas fitter.
WARNING
The Pennant pool 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 CAN/CGA-B149.1,
Natural Gas Installation Code or CAN/CGA-B149.2,
Propane Gas Installation Code, and/or 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 Pennant copper tube pool heaters.
Read it carefully before installation.
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 fitted 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" W.C. (3.2kPa).
All installations must be made in accordance
with the 1). American National Standard Z223.1/
NFPA54-Latest Edition “National Fuel Gas Code” or
2). CAN/CGA 1-B149 “Installation Codes for Gas
Burning Appliances and Equipment” and with the
requirement of the local utility or other authorities
having jurisdiction. Such applicable requirements take
precedence over the general instructions contained
herein.
All electrical wiring is to be done in accordance
with the local codes, or in the absence of local codes,
with: 1). The National Electrical Code ANSI/NFPA
No. 70-latest Edition, or 2). CSA STD. C22.1
“Canadian Electrical Code - Part 1”. This appliance
must be electrically grounded in accordance with these
codes.
1.2 Model Identification
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
P = Pool Heater
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 = Liquid Propane
10 Altitude
A = 0-10,000 feet
11 Location
C = Indoor and Outdoor
12 Firing Mode
C = On-off
1234567891011 12 13 14 1516
PNC P A C C 2 N
SERIES
PN C USAGE PSIZE 0500
0750
1000
1250
1500
1750
2000
FUEL
N
P
ALTITUDE
AFIRING
MODE
C(ON/OFF)
LOCATION
CREVISION 2HEAT
EXCHANGER
B
C
K
N
P
S
OPTIONS
CODE
X
J
L
PUMP
OPTIONS
N

LAARS Heating Systems
Page 4
13 Revision
2 = Second version
14 Heat Exchanger
B = Glass-lined CI / copper / brz trim (std. PNCP)
K = Bronze / copper
P = Glass-lined cast iron / cu-nickel / brz trim
S = Bronze / cu-nickel
15 Option Code
X = Standard unit
J = CSD-1, FM, IRI, IL
L = MN and LDS (Indoor units only)
16 Pump Options
N = Pump mounted, normal pump
1.3 Warranty
Laars Heating Systems’ Pennant appliances are
covered by a limited warranty. The owner should fill
out the warranty registration card and return it to Laars
Heating Systems.
All warranty claims must be made to an
authorized Laars Heating Systems representative or
directly to the factory. 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
filed 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 floors 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 certified by CSA-
International for installation on combustible flooring;
in basements; in closets, utility rooms or alcoves. 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
above grade.
The dimensions and requirements that are shown
in Table 2 should be met when choosing the locations
for the appliance.
HORIZONTAL AIR COLLAR
HEATER 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 8 20 615 615 50 15 3 CA001401 20260701
750 10 25 820 615 50 15 3 CA001402 20260701
1000 10 25 820 820 50 15 3 CA001402 20260703
1250 12 30 820 820 50 15 3 CA001403 20260703
1500 12 30 820 820 50 15 3 CA001403 20260703
1750 14 36 8 20 820 50 15 3 CA001405 20260703
2000 14 36 12 30 12 30 50 15 3 CA001404 20260706
*Horizontal venting requires stainless vent pipe. See Table 5.
Table 1. Horizontal Vent / Combustion Air Parameters.

Pennant Pool Heater Page 5
Figure 1. Dimensional Data.
AIR VENT HORIZ.
CONN. CONN. VENT
SIZE A B C D E F G H W* V* PIPE
500 33½ 85 15¾ 40 5¾ 15 29¾ 76 32¾ 83 7¾ 20 8¾ 22 46 117 615 820 615
750 45½ 116 21¾ 55 5¾ 15 29¾ 76 32¾ 83 7¾ 20 8¾ 22 58 147 615 10 25 820
1000 57½ 146 28¾ 73 5¾ 15 29¾ 76 32¾ 83 7¾ 20 718 70 178 820 10 25 820
1250 68 172 34 86 101/826 30¾ 78 29½ 75 8¾ 22 8¾ 22 80 203 820 12 30 820
1500 78½ 199 39¾ 101 101/826 30¾ 78 29½ 75 8¾ 22 8¾ 22 91 231 820 12 30 820
1750 89 226 44½ 113 101/826 30¾ 78 29½ 75 8¾ 22 8¾ 22 101 256 820 14 36 820
2000 99½ 253 49¾ 126 101/826 30¾ 78 29½ 75 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 field convertible. Dimensions in inches cm.
Shipping Weight
Size lbs. kg
500 480 218
750 560 254
1000 670 304
1250 730 331
1500 815 370
1750 880 400
Dimensions shown in
inches cm

LAARS Heating Systems
Page 6
REQUIRED RECOMMENDED
APPLIANCE CLEARANCE FROM SERVICE ACCESS
SURFACE COMBUSTIBLE MATERIAL CLEARANCE
inches cm inches cm
Left Side 1 2.5 24 61
Right Side 1 2.5 24 61
Top 1 2.5 12 30
Back 1 2.5 **12** 30**
Front 1 2.5 36 91
Vertical
(Category 1) 6* 15.2*
Vent
Horizontal per UL1738 venting
(Category 3) system supplier’s
Vent instructions
*1" (2.5cm) when b-vent is used.
**When vent and/or combustion air connects to the back,
recommended clearance is 36" (91cm).
Table 2. Clearances.
BOILER EACH OPENING*
SIZE 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 floor level and
one at the ceiling, so the total net free area could be double the
figures 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.
SECTION 2.
Venting and Combustion Air
2.1 Combustion Air
Pennant pool heaters must have provisions for
combustion and ventilation air in accordance with
section 5.3, Air for Combustion and Ventilation, of the
National Fuel Gas Code, ANSI Z223.1, or Sections
7.2, 7.3 or 7.4 of CAN/CGA B149, Installation Codes,
or applicable provisions of the local building codes.
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.
Ventilation air must be provided in either case. Never
obtain combustion air from the pool area. Corrosion of
and/or damage to the pool heater may result.
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
1.6 Locating Heater with Respect to Pool
System Loop
For the best results, the Pennant should be
located within 15 feet (4.6m) of the pool system loop.
The pump is sized for 30 feet (9.1m) of piping.
If the appliance must be installed with longer
piping runs, then larger diameter piping shall be used.
Consult the factory for assistance.
1.7 Locating Appliance for Correct
Horizontal Vent/Ducted Air Distance
From Outside Wall
The forced draft combustion air blower/blowers
in the appliance has/have sufficient power to pull air
and vent properly when the following guidelines for
horizontal air and vent are followed (see Table 1).
NOTE: On all model sizes, 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. Never obtain combustion air from the pool
area. Corrosion of and/or damage to the pool heater
may result.

Pennant Pool Heater Page 7
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 Permanent duct tape or aluminum tape
Sealing
Table 4. Required Combustion Air Piping Material.
(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 confined 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
CAN/CGA B149.
2.1.2 Intake Combustion Air
Never obtain combustion air from the pool area.
Corrosion of and/or damage to the pool heater may
result. 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 1). When
taken from the roof, a field-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 1 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)
linear run. Subtract 10 allowable linear feet (3.0m) for
every additional elbow used (see Table 1). 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
filter box. The 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 flanges are reversible by removing the
mounting screws and orienting the flanges in the
desired position. Replace the screws after positioning
flanges. 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
(American National Standard Z223.1-Latest Edition),
or in Canada the CSA B149.1 (latest edition), defines
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.

LAARS Heating Systems
Page 8
2.2.2 Category I Vent
When vented as a category I appliance, the vent
system must conform to the National Fuel Gas Code
(American National Standard Z223.1-Latest Edition)
in the U.S., or in Canada, to 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 flue draft does not exceed
(negative) 0.1" w.c.
If using a power venter for any type of Category
I venting, the draft should be set between (negative)
0.01 and 0.10" 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
qualified engineer.When common venting Pennant
fan-assisted heaters 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 infiltrate 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.
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 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
backpressure indicating a blocked vent condition, that
all appliances attached to the vent be locked out and
prevented from operating. (Note that the Pennant Pool
Heater is equipped with a blocked vent safety
(pressure) switch, as shipped.) 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 telephone
number on 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 flue gasses 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. Reference Table 1 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 Laars side wall vent hood (listed in Table 1)
must be used when the heater is vented through a side
wall. It provides a means of installing 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 CAN/CGA B149.1 or .2 and
TERM DESCRIPTION
Pipe Must comply with UL Standard 1738
such as Type 29-4C Stainless Steel
(either insulated or non-insulated).
Joint Follow vent manufacturer’s instructions
Sealing
Table 5. Required Horizontal Venting Material.

Pennant Pool Heater Page 9
Figure 3. Combustion Air and Vent Through Side Wall.
*When vent terminal is less than 10 feet (3m) horizontally
from a forced air inlet, the terminal must be at least 3 feet
(0.9m) above the air inlet.
local applicable codes (see Figure 3). Consider the
following when installing the terminal:
1. Through-the-wall vent terminals must terminate
at least 7-feet above a public walkway.
2. Locate the vent terminal so that vent gases
cannot be drawn into air conditioning system
inlets. The National Fuel Gas Code requires that
it be at least 3 feet (0.9m) above any such inlet
that is within a horizontal distance of 10 feet (3m).
3. Locate the vent terminal so that vent gases
cannot enter the building through doors,
windows, gravity inlets or other openings. The
National Fuel Gas Code requires that it be
located at least 4 feet (1.2m) below, 4 feet (1.2m)
horizontally from, or 1 foot (0.3m) above such
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 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.
5. Locate the terminal so the vent exhaust does not
settle on building surfaces and other nearby
objects. Vent products may damage such
surfaces or objects.
6. Locate the terminal at least 6 feet (1.8m)
horizontally from any gas or electric metering,
regulating, or relief equipment.
7. If the Pennant uses ducted combustion air from
an intake terminal located on 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.
8. Note that side wall vent terminals for models
750-2000 are shipped with reducers for the vent
collars, to accommodate horizontal vent sizes,
shown in Table 1.
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.
2.3.2 Side Wall Combustion Air Terminal
Never obtain combustion air from the pool area.
Corrosion of and/or damage to the pool heater may
result. The Laars side wall combustion air terminal
(listed in Table 1) 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 fluid,
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

LAARS Heating Systems
Page 10
OUTDOOR VENT OUTDOOR
SIZE TERMINAL 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
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
field-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 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.
Part numbers for the terminals to cover the vent
and combustion air openings are shown in Table 6.
Vent opening must be on top of the unit, and the
combustion air opening must be on the back of the
unit. The terminals are connected directly to the unit.
No vent piping is used.
Alternately, the installer may use a short piece of
galvanized single wall or B-vent and an approved rain
cap for the vent termination. A minimum 12" of vent
height is acceptable. In addition, a properly sized
single wall galvanized 90° ell can be used for the
intake air terminal, with the open end of the ell facing
down to prevent rain infiltration. The combustion air
inlet opening must still be high enough to prevent
blockage by snow (see Section 2.3.2).

Pennant Pool Heater Page 11
DISTANCE FROM GAS METER
SIZE AND OR LAST STAGE REGULATOR
GAS TYPE 0-100' 0-31m 100-200' 31-61m 200-300' 61-91m
500 natural 1-1/2" 3.8cm 2" 5.1cm 2" 5.1cm
500 propane 1" 2.5cm 1-1/2" 3.8cm 1-1/2" 3.8cm
750 natural 2" 5.1cm 2" 5.1cm 2-1/2" 6.4cm
750 propane 1-1/2" 3.8cm 1-1/2" 3.8cm 2" 5.1cm
1000 natural 2" 5.1cm 2-1/2" 6.4cm 3" 7.6cm
1000 propane 1-1/2" 3.8cm 2" 5.1cm 2-1/2" 6.4cm
1250 natural 2-1/2" 6.4cm 2-1/2" 6.4cm 3" 7.6cm
1250 propane 2" 5.1cm 2" 5.1cm 2-1/2" 6.4cm
1500 natural 2-1/2" 6.4cm 3" 7.6cm 3" 7.6cm
1500 propane 2" 5.1cm 2-1/2" 6.4cm 2-1/2" 6.4cm
1750 natural 2-1/2" 6.4cm 3" 7.6cm 3" 7.6cm
1750 propane 2" 5.1cm 2-1/2" 6.4cm 2-1/2" 6.4cm
2000 natural 3" 7.6cm 3" 7.6cm 3-1/2" 8.9cm
2000 propane 2-1/2" 6.4cm 2-1/2" 6.4cm 3" 7.6cm
Notes:
1. These figures are based on 1/2" (0.12kPa) water column
pressure drop.
2. Check supply pressure and local code requirements before
proceeding with work.
3. Pipe fittings must be considered when determining gas pipe
sizing.
Table 7. Gas Piping Size.
SECTION 3.
Gas Supply and Piping
3.1 Gas Supply and Piping
Gas piping should be supported by suitable
hangers or floor 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 fitted for the proper
type of gas by checking the rating plate. Laars
Heating Systems appliances are normally
equipped to operate at elevations up to 2000
feet (610m). Pennant appliances may be adjusted
to operate properly at higher elevations;
however, 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" W.C. (1.2kPa).
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 liquefied
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 1/2 PSIG (3.45kpa).
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 1/2 PSIG (3.45kpa).
10. The appliance and its gas connection must be
leak tested before placing it in operation.
11. Purge all air from gas lines.
Caution
Do not use open flame to check for leaks.
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. The Pennant may not fire if
the gas pressure lower than 5" w.c.
Figure 4. Typical Gas Train Configuration.

LAARS Heating Systems
Page 12
temperature at or above 120°F (49°C) (see Figure 5).
This keeps cold return water from causing condensing
on the outside of the Pennant heat exchanger.
IMPORTANT NOTE: Since heater outlet
temperatures can reach 150°F (66°C) in some cases,
copper or CPVC are recommended materials for
heater connection piping. PVC material may be used
for the inlet valve and the piping upstream of it.
When pipe, fittings, grids or any other element of
the filter system are made of plastic materials, they
may be damaged by the momentary “back siphoning”
of hot water from the heater when the filter pump
stops running.
See Figure 6 for proper connection of the
Pennant heater to the pool loop.
SECTION 4.
Water Connections
4.1 Piping
Hot water piping should be supported by suitable
hangers or floor 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 shutoff valves where required
by code.
Pennant Pool Heaters are equipped with mounted
pumps, which serve the heater plus 30 feet of full-
sized piping with a normal number of fittings. If the
pool’s loop is more than 15 feet away from the heater,
please contact the factory.
A mixing system is mounted on the heater. The
system consists of a three-way valve, temperature
control and piping. The temperature sensor for the
control is in the heater inlet. When the control detects
water temperature that is below 120°F (49°C), it will
direct the three-way valve to actuate, which sends
water from the outlet of the heater back to the inlet.
The outlet water that is diverted to the inlet mixes with
the return water from the pool, and keeps the inlet Figure 5. Mixing System.
Mixing Controller
Sensor (120°F)
Pool Loop / Inlet
(2 used)
Figure 6. Pool Heater Piping.
The Pennant Pool Heater is shipped with a field-installed mixing system, and must be piped in primary-
secondary style, as shown. A remote pool temperature sensor and remote pool temperature high limit
are wired to the Pennant, to be mounted in the pool water loop, as shown.

Pennant Pool Heater Page 13
4.2 Automatic Chlorinators
A concentration of chlorine in the heater can be
very destructive; therefore the following rules about
the installation and operation of such devices must be
followed:
1. The chlorinator should be installed so it introduces
the gas or solution downstream of the heater.
2. The chlorinator should be wired so it cannot
operate unless the filter pump is operating.
3. The chlorinator should be provided with an anti-
siphon device so that the draining of the piping
after the pump shuts off will not siphon chlorine
solution into the heater.
4. When the operation of a chlorinator is such that
it must be installed in the pump suction, or some
other place where the chlorine solution flows
through the heater, corrosion of the heater can
occur. Excessive concentrations of chlorine
resulting from improper adjustment or
chlorinator equipment failure are responsible for
this corrosion. The heater warranty does not
cover the resulting damage to the heat exchanger.
4.3 Sensor Locations
Two sensors must be installed in the pool loop,
as shown in Figure 6. The inlet sensor for the
temperature control must be installed in the pool loop
within 12” (30 cm) of the inlet to the heater. This
sensor is not installed in a well. For sensitivity, it must
be installed in direct contact with the pool water flow.
The second sensor, the high limit sensor, must be
installed in the pool loop within 12” (30 cm)
downstream of the heater outlet. This sensor is a
capillary and bulb. It shall be used with the immersion
well that is provided.
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.
Single pole switches, including those of safety
controls and protective devices must not be wired in a
grounded line.
All electrical connections are made in the field
wiring terminal strip, which is located at the right side
of the appliance.
NOTE: All internal electrical components have been
prewired. No attempt should be made to connect
electrical wires to any other location except the field
wiring strip.
5.1 Main Power
5.1.1 Sizes 500-1500
Pennant pool heater sizes 500-1500 use a single
120-volt fused supply. The installer can change the
single service heaters to use a separate circuit for the
pump, if desired. Instructions to make this change are
found in Section 5.1.3.
Pennant 500-1500 main power (L1, N1 &
Ground) shall be connected to the three wires (10
AWG) supplied. Over-current protection ratings can
be found in Table 8.
5.1.2 Sizes 1750-2000
Pennant Sizes 1750-2000 require two 120-volt
fused supplies.
Heater circuit can be identified with 10AWG
wires to include black, white and green (all solid
colors). Pump circuit can be identified with three
12AWG wires to include a black wire with a white
tracer (stripe), a white and green wire.
5.1.3 Separate Pump Circuit
Conversion to separate pump circuit will
necessitate removing the three jumpers within the
internal wiring of the 120-volt portion of the heater
(see Figure 7). Only do this with the power
disconnected to the unit!
To rewire the pump circuit, bring in another
120-volt fused supply (L2, N2 & Ground). Connect
incoming power (L2) to the main power switch using

LAARS Heating Systems
Page 14
spade (fork) terminal. From the other side of the main
power switch connect to the main terminal block using
a ¼" female insulated quick connect. This will be the
same position where the jumper had terminated (see
Figure 7). Connect N2 and Ground to the main
terminal block using ¼" female insulated quick
connect (refer to Figure 7).
5.1.4 Auxiliary Time Clock Wiring
If a time clock is used to control the pool filter
pump operation, a separate switch or relay must be
used to shut off the heater at least 15 minutes before
the filter pump is shut off. A remote switch or relay,
if installed, should be connected across the “Other
Ints” terminals on the field-wiring terminal strip (see
Figure 9) after removing the factory-installed jumper
from those terminals. For manual shut off, a switch is
provided and identified with a label on the right side
of the heater.
All field-installed electrical safety devices and
controllers may also be connected across the
Pennant’s “Other Ints” terminals after the factory-
installed jumper is removed. If a remote switch or
relay (mentioned above) is installed, the other field-
installed electrical safety devices and controllers
should be wired in series with that switch or relay.
5.1.5 All Sizes
Wiring diagrams are shown in Section 10 in
Figures 13 through 17. Field wiring is shown in
Section 10 in Figure 18.
IMPORTANT NOTE: If the backwash operation is
manual the heater must be shut off manually during
backwashing.
5.2 Temperature (Operating) Control
The Pennant temperature control operates by
measuring the pool loop return temperature, before the
heater inlet piping. It is adjustable to a maximum of
104° F and will prevent heater operation at return
temperatures above 104° F. It also controls the pool
heater pump and the temperature of the water entering
the heat exchanger. It also controls the Pennant pump
operation and the mixing system, which tempers the
water entering the heat exchanger to prevent damage
from condensation. The sensors for the control are
installed as shown in Figure 6 and Section 4.3, Sensor
Locations. The automatic mixing system sensor, already
installed, is shown in Figure 5. During operation, the
automatic mixing system diverts water from the outlet to
the inlet to “pre warm” the water to a minimum inlet
temperature of 120°F. This prevents condensation from
forming, which can damage the heater.
5.3 Programming the Temperature
Control
5.3.1 Temperature Control Overview
The digital display on the control has the
following uses:
• To display the actual pool loop temperature
during normal operating mode.
• To allow the user to view and adjust the
control settings.
Figure 8 identifies the control buttons.
The Pool Heater Temperature Control face
contains an LCD screen and four (4) buttons (see
Figure 8). The LCD screen will display the pool loop
return temperature during normal operation. When the
control is first powered up, it displays . It then
displays the temperature at the pool loop sensor. After
the temperature is displayed, the current settings
(parameters) may be viewed. To scroll through the
parameters, press the down arrow button to advance to
the next parameter.
5.3.2 Programming Control Parameters
There are four (4) control parameters that may be
set. They are the Pool Loop Temperature (LSP), the
Pool Loop Temperature Differential (dLS), the Boiler
Temperature (bsp) and the Pump Off Delay (Pd).
The pool loop temperature (desired pool temp-
erature) is set by changing the LSP parameter. After
scrolling through the parameters until LSP is displayed,
press the enter button. The setpoint will be displayed.
Press the up arrow or down arrow buttons until the
desired setpoint is displayed. Press the enter button and
the setpoint will be activated. The display will return to
indicating the present pool loop temperature.
In addition to the ability to set the pool loop
temperature, the differential associated with that
setting may also be adjusted. The differential is set by
changing the dLS parameter. After scrolling through
the parameters until dLS is displayed, press the enter
Figure 7. Removing Jumpers.

Pennant Pool Heater Page 15
button. The setpoint will be displayed. Press the up
arrow or down arrow buttons until the desired setpoint
is displayed. Press the enter button and the setpoint
will be activated. The display will return to indicating
the present pool loop temperature.
The boiler operating temperature is set by
changing the bsp parameter. After scrolling through
the parameters until bsp is displayed, press the enter
button. The setpoint will be displayed. Press the up
arrow or down arrow buttons until the desired setpoint
is displayed. Press the enter button and the setpoint
will be activated. The display will then return to
indicating the pool loop temperature.
SINGLE TWO CIRCUIT
SIZE CIRCUIT HEATER PUMP
500 20 15 15
750 20 15 15
1000 20 20 15
1250 30 25 15
1500 30 25 15
1750 25 20
2000 25 20
Table 8. Electrical Data (Amps).
Figure 9. Typical Control Panel.
Figure 8. Pool Heater Controller.
The last parameter that may be adjusted is Pd, the
pump off delay. After again scrolling through the
parameters until Pd is displayed, press the enter button.
The pump delay time will be displayed. The pump off
delay may be set between 0.1 and 10 minutes. Press the
up arrow or down arrow buttons until the desired setpoint
is displayed. Press the enter button and the setpoint will
be activated. The display will again return to indicating
the present pool loop temperature.
By depressing the upper left hand button at any
time during the programming, the menu may be
returned to the beginning.
5.3.3 Setpoint - LSP
The setpoint is the desired temperature around
which the heater will control (desired pool temp-
erature). It is adjustable between 60° F and 104° F.

LAARS Heating Systems
Page 16
SECTION 6.
Operating Instructions
6.1 Sequence of Operation
The amber “Ready” light on the front panel
indicates that the control system is energized. Upon a
call for heat from the pool temperature control, the
green “Heat” indicator on the front panel will light.
The green “Pump” indicator on the front panel
will light.
Once the water flow switch makes, and if all of
the safety interlocks are closed, the ignition module(s)
will energize the blower(s) for a 15-second pre-purge,
followed by a 20-second period to allow the ignitor(s)
to heat.
Energizing the blower pressurizes the air box
(which supplies air to the burners) and closes the
normally-open contact(s) of the airflow pressure
switch(es). This allows the ignition module to proceed
with the ignition sequence.
The blocked flue pressure switch senses the
pressure difference between the exhaust plenum and
the blower inlet plenum. It will interrupt the airflow
sensing circuit if this pressure exceeds a maximum
value. If airflow is not proven, the ignition module
will either attempt ignition again (up to three times) or
will lockout (if the optional lockout ignition module is
used).
The ignition module checks that the ignitor
current has reached a minimum value and energizes
the gas valves at the end of the ignitor-heating period.
The green indicators on the front panel will light,
indicating that the gas valves are open.
After a 4-second trial for ignition, the ignitor
switches off, and unless the flame sensor detects a
flame, the gas valves will close and the ignition
module will either attempt ignition again (up to three
times) or will lockout (if the optional lockout ignition
module is used). Note: at this point, if gas pressure is
below the required 5" w.c. minimum, the pool heater
will lock out.
If flame is sensed, the burner will continue to fire
as long as there is a call for heat. Pennant 1250, 1500,
1750 and 2000 models start at part load. When the gas
valves controlled by the first ignition module are
energized, the second ignition module is energized and
enters the same ignition sequence just described. If
there is a subsequent loss of flame signal, the burner
will attempt re-ignition up to three times (only once if
optional lockout ignition module is used.) Loss of
flame signal from the first ignition module will cause
shutdown of the heater.
When the call for heat is satisfied, the gas valves
close and the blower(s) continues to run for 30
seconds. The pump will continue to run for the length
of time selected at startup by the adjustment of the
pump time delay (Pd).
5.3.4 Differential - dLS
The differential (dLS) is the number of degrees
between the temperature at which the heater turns off
and the temperature at which the heater restarts. It is
adjustable from 1° F to 10° F.
5.3.5 Pump Operation
The pump energizes when there is a heat demand.
5.3.6 Heater Purge (Pump Delay) - Pd
After a demand is satisfied, the pump will
continue to run for a preset length of time. That length
of time is adjustable from 0.1 to 10 minutes and is
programmed by the parameter Pd.
Caution
Should overheating occur or the gas supply fail to
shut off, turn off the manual gas control valve to the
appliance.
5.4 Limit Controls
In addition to the pool heater temperature
control, Pennant appliances are fitted with a Pool
Loop high limit set at 135° F and an automatic reset
heater high limit with a maximum setting of 190° F.
The Pool Loop high-limit sensing bulb is to be
installed in the sensor well (supplied), downstream of
the heater (see Figure 6). If sufficient capillary length
exists to reach the sensor location, the control may
remain in its location near the rear of the cabinet on
the right side, behind the slide out drawer (see Figure
9). If the sensor location is farther from the heater than
the capillary will reach to, then the control should be
moved to the remote location and the wires extended to
the new location of the control. If the controller needs to
be moved, and it is being moved to an outdoor location,
the control will need to be put in a weather-tight
enclosure to protect it from rain, snow, etc.
The other limit control limits the temperature of
the discharge from the heat exchanger to a maximum
of 190° F. This limit should be set to a minimum of
175° F. To set the limit controls, remove the control
panel cover and pull the control panel out to gain
access. Appliances with reversed heat exchangers have
the limit controls relocated to the left side of the
appliance. The left access door must be removed to
gain access to the limit controls on these appliances.

Pennant Pool Heater Page 17
If a call for heat is prevented from being satisfied
either by a safety interlock or due to an ignition
lockout, the red “Service” indicator on the front panel
will light. To reset the standard ignition module,
toggle the Pennant power switch off, and then on
again. (To reset the optional single try lockout ignition
module, the reset button on the module must be
pressed. Interrupting power to this module will not
reset the lockout.)
The Pennant 1250, 1500, 1750 and 2000 models
have two ignition modules that control different
burners.
6.2 Filling the Heater System
1. Ensure the system is fully connected, filled with
water and all valves are open.
2. Start up heater according to the procedure in this
manual. Operate the entire system for one (1) hour.
3. After placing the unit in operation, the ignition
system safety shutoff device must be tested.
First, shut off the manual gas valve, and call the
unit for heat. After the pre-purge and ignitor
heat-up time, the main gas terminals will be
energized, attempting to light, for four (4)
seconds, and then will de-energize. The unit will
go into lockout mode. Second, turn the power off
and then on again, push the reset button (optional
Ignition Module only), open the manual gas
valve and allow the unit to light. While the unit
is operating, close the manual gas valve and
ensure that power to the main gas valve no
longer exists.
4. Check the entire system for leaks.
Caution
Protect the heater from low pH water if an “acid
start up” or similar technique is used. Corrosion of
the heater and heat exchanger due to low pH water
is not covered under the limited warranty. The water
must be neutralized to normal pH levels before
filling the heater and starting up the system.
Important: The installer is responsible for identifying
to the owner/operator the location of all emergency
shutoff devices.
WARNING
Do not use this appliance if any part has been
under water. Immediately call a qualified service
technician to inspect the appliance and to replace
any part of the control system and any gas control
that may have been under water.
6.3 Operating the Burner and Set Up
6.3.1 Set Up for 0 to 2500 Feet Altitude
The setup must be checked before the unit is put
in operation. Problems such as failure to start, rough
ignition, strong exhaust odors, etc. can be due to
improper setup. Damage to the heater resulting from
improper setup is not covered by the limited warranty.
1. Using this manual, make sure the installation is
complete and fully in compliance with the
instructions.
2. Determine that the appliance and system are
filled with water and all air has been bled from
both. Open all valves.
3. Observe all warnings on the Operating
Instructions label and turn on gas and electrical
power to appliance.
4. Switch on the appliance power switch located on
the right side of the unit.
5. The Pennant will enter the start sequence, as long
as the unit is being called for heat. The blower
and pump come on for pre-purge, then the ignitor
warm-up sequence starts and after the ignitor
warm-up is complete and all safety devices are
verified, the gas valves open. If ignition doesn’t
occur, check that there is proper gas supply. Wait
5 minutes and start the unit again. During initial
start up, air in the gas line may cause the Pennant
to "lock out" during the first few trials for
ignition. Depending on the ignition modules
installed, the manual reset button on the ignition
module(s) may need to be depressed to restart the
heater.
6. When the unit is running, the supply gas pressure
must be checked. Inlet gas pressure must not
exceed 13" W.C. (3.2kPa). The minimum inlet
gas pressure is 5" W.C. (1.2kPa).
7. Once the inlet gas pressure is verified, the outlet
gas pressure from each valve (manifold gas
pressure) must be checked, and adjusted, if
necessary. The manifold gas pressure must be
2.5" W.C. (0.62kPa).
8. Complete the setup by checking the CO2at the
outlet of the unit. The CO2should be 8% for
natural gas, or 9.2% for propane.
9. After placing the appliance in operation, the
Burner Safety Shutoff Device must be tested.
To test:
(a) Close gas shutoff valve with burner
operating.
(b) The flame will go out and blower will
continue to run for the post purge cycle.
Three (3) additional attempts to light will
follow (only one (1) attempt for optional
module). Ignition will not occur as the gas
is off. The ignition control will lockout, and
will have to be reset before the unit will
operate. The ignition control reset button is
located on each ignition control, in the
lower right corner, and can be reset by
depressing. It is not marked on the ignition
control label.
(c) Open gas shutoff valve. Restart the
appliance. The ignition sequence will start

LAARS Heating Systems
Page 18
HEATER MINIMUM FILTER
MODEL PUMP FLOW RATE
PNCP 500 240 GPM
PNCP 750 360 GPM
Table 9. Minimum Filter Pump Flow Rates For Spas.
again and the burner will start. The
appliance will return to its previous mode
of operation.
NOTE: Models 1250, 1500, 1750 and 2000 have two
ignition controls and two ignitors.
6.3.2 High Altitude Adjustment and Set Up
Pennant appliances may be operated at high altitude
(7700 ft., 2347 m) with a reduction in output of
approximately 10%. At elevations higher than 7700 ft.
(2347 m) the reduction in output will exceed 10% and at
elevations below 7700 ft. (2347 m) it will be less than
10%. When adjusted properly, the appliance will perform
properly at any altitude. High altitude adjustment must
not be made on appliances operating at elevations below
2500 ft. (762 m).
No orifice changes are required to adjust the
Pennant appliances for high altitude. High altitude
adjustment is accomplished by adjustment of the gas
valve manifold pressure and the air shutter(s). The
required instruments used to assist in these
adjustments are a CO2or O2Analyzer and a U-Tube
Manometer or other device capable of reading a
pressure of 2.5-3.0 inches W.C. (0.62-0.75 kPa).
Start the adjustment process by checking the CO2
in the “as installed” condition. Adjust the air shutter(s)
so that the CO2is about 8% or the O2is about 6.8% for
appliances operating on Natural Gas. For appliances
operating on LP Gas adjust the air shutter(s) so that
the CO2is about 9.2% or the O2is about 6.8%.
Appliances with two blowers should be adjusted so
that the air shutters below each blower are open the
same amount.
Once the CO2or O2has been set, the manifold
pressure may be adjusted. Remove the 1/8 NPT plug
from the lower side of the gas valve that is to be set
and install a fitting, hose and manometer. Start the
appliance and observe the manifold pressure. Manifold
pressure must be adjusted to 3.0 in. W.C. (0.75 kPa)
(for high altitude only, standard operating pressure is
2.5 in. W.C. (0.62 kPa)). It is adjusted by removing the
slotted cap on the gas valve and turning the adjustment
screw (beneath the cap) clockwise to increase pressure
. After the adjustments have been completed, the
fitting, hose and manometer have been removed and
the 1/8" plug has been replaced, replace the cap.
Repeat this process until all gas valves have been set.
Note: The pressure can be set only when the appliance
is operating and only when the particular gas valve
being adjusted is energized by a call for heat.
After all of the gas valve manifold pressures
have been set, the CO2or O2must be reset. CO2or O2
will have changed when the manifold pressure was
adjusted. Open the air shutter(s) to reduce the CO2or
O2to the values achieved previously.
The procedure is complete when all gas valves
are adjusted to a manifold pressure of 3.0 in. W.C.
(0.75 kPa) and the CO2is adjusted to 8.0% for Natural
Gas appliances or 9.2% for LP appliances. When
using an O2analyzer, the correct O2is 6.8% for both
Natural Gas and LP appliances.
Caution
Should any odor of gas be detected, or if the gas
burner does not appear to be functioning in a
normal manner, close main shutoff valve, do not
shut off switch, and contact your heating contractor,
gas company, or factory representative.
6.4 Shutting Down the Pennant
1. Switch off the shutdown switch (located above
the Main Power Switch).
2. Wait until the “pump” light (located on the front
panel) goes out.
3. Switch off the main electrical disconnect switch.
4. Close all manual gas valves.
5. If freezing is anticipated, drain the Pennant and
be sure to also protect piping connected to the
Pennant from freezing.
This step to be performed by a qualified service person.
6.5 Backwash Switch Operation
Pennant Pool Heaters are equipped with a filter
backwash switch, which is located above the main
power switch. The switch is intended to provide a
means by which the heater can be safely shut down for
pool filter service, without causing nuisance tripping
of the heater high limit.
This switch is internally wired in series with the
Other Interlocks terminals, and will interrupt the call
for heat signal when open. Please note that when the
backwash switch is active the heater “Service” light
will be illuminated.
To place the heater into backwash mode proceed
as follows:
1. Turn the backwash switch down to the “Filter
Backwash Mode” position.
2. Wait for the heater outlet temperature to drop
down to a temperature equal to the pool water
return temperature.
3. Turn the main power switch off.
Pool filter servicing may now proceed normally.
After completion of the filter servicing, place the
heater back into service as follows:
1. Turn the main power switch on.
2. Allow time for the pump to turn on, and purge
air from the heater.
3. Turn the backwash switch up to the “Normal”
position.

Pennant Pool Heater Page 19
The service light will turn out, and the heater
will resume normal operation. Please note that if the
heater is equipped with a low water cut off there will
be a brief delay while the LWCO completes a self-
check.
6.6 Spring and Fall Operation
Stand-by Service
Turn the thermostat down to approximately 70°F
(21°C). This will prevent the pool and surrounding
ground from becoming chilled and permit the pool to
be raised to swimming temperature in a shorter length
of time. Do Not Operate below 60°F (16°C).
6.7 Winter Operation
Complete Shutdown
1. See Section 6.4
2. If the heater is not protected from freezing
temperatures, it should be completely drained
before the first frost. Drain the heater by
removing the plug at the end of the inlet/outlet
header casting. Also, remove the small plug at
the bottom of the pump housing. Do not replace
either plug until the time that refilling is desired.
The heater must be level for complete draining.
When compressed air is used to blow out lines, it
is still necessary to follow these directions.
Because of the potential for electrical power
failure or pump failure, freeze protection should
never be accomplished by operating the pool
heater and the filter pump. Either of those
failures will potentially allow a freeze up and
cause damage to the heater and the attached
system.
3. Improper use of the heater: The Laars PNCP
pool heater is not designed for continuous use as
a “anti-freezing” device for pools. Operating the
heater at low water temperatures will damage the
heat exchanger.
6.8 To Restart the Pennant
If drained, follow Section 6.2 in this manual for
proper filling and purging.
1. Switch off the main electrical disconnect switch.
2. Close all manual gas valves.
3. WAIT FIVE (5) MINUTES.
4. Set the pool aquastat to its lowest setting.
5. Open all manual gas valves.
6. Reset all safety switches.
7. Set the temperature controller to the desired
temperature setting and switch on electrical
power.
8. Burner will go through a prepurge period and
ignitor warm-up period, followed by ignition.
6.9 Therapeutic Pools (Spas)
Therapeutic pools or “spa” pools are usually
piped and controlled so that very warm or hot water,
often with air injection, is forced at high velocity into
a confined area of a swimming pool or into a small
separate pool. For the purposes of this manual, any
application in which the water temperature is
maintained above 85°F (30°C) is considered a spa.
SPECIAL SET-UP AND OPERATING
PROCEDURES APPLY TO SPAS.
1. Models PNCP1000 and larger should not be
used for spas due to their higher temperature
rises.
2. To ensure that the spa inlet does not exceed 104°F
(40°C), the spa filter pump must circulate water
at the minimum flow rates shown in Table 9.
NOTE: Maximum Spa Temperature Is Assumed To Be
100°F (38°C).
3. Spas are excellent for relaxation, body-
conditioning and for arthritic and rheumatic
problems, but can be hazardous.
WARNING
The U. S. Consumer Product Safety Commission
has warned that elevated temperatures in spas and
hot tubs can be hazardous. Follow these “Safety
Rules for Hot Tubs:”
• Spa or hot tub water temperatures should never
exceed 104°F (40°C). A temperature of 100°F
(38°C) is considered safe for a healthy adult.
Special caution is suggested for young children.
• Drinking of alcoholic beverages before or
during hot tub use can cause drowsiness,
which could lead to unconsciousness and
subsequently lead to drowning.
• Pregnant women beware! Soaking in water
above 102°F (39°C) can cause fetal damage
during the first three months of pregnancy
(resulting in the birth of a brain-damaged or
deformed child). Pregnant women should stick
to the 100°F (38°C) maximum rule.
• Before entering the spa or hot tub, users should
check the water temperature with an accurate
thermometer; spa or hot tub thermostats may
err in regulating water temperatures by as
much as 4°F (2°C).
• Persons with a medical history of heart disease,
circulatory problems, diabetes or blood pressure
problems should obtain their physician’s advice
before using spas or hot tubs.
• Persons taking medications which induce
drowsiness, such as tranquilizers,
antihistamines or anticoagulants, should not
use spas or hot tubs.

LAARS Heating Systems
Page 20
SECTION 7.
Maintenance
7.1 System Maintenance
1. Lubricate the system water-circulating pump, if
required, per the instructions on the pump.
2. Inspect the venting system for obstruction or
leakage at least once a year. Periodically clean the
inlet air filter and the screens in the vent terminal
and combustion air terminal (when used).
3. Keep the appliance area clear and free from
combustible materials, gasoline, and other
flammable vapors and liquids.
4. If the appliance is not going to be used for
extended periods in locations where freezing
normally occurs, it should be isolated from the
system and completely drained of all water. All
systems connected to it should also be drained or
protected from freezing.
5. Low water cutoffs, if installed, should be
checked every 6 months. Float type low water
cutoff should be flushed periodically.
6. Inspect flue passages, and clean with brushes/
vacuums, if necessary. Sooting in flue passages
indicates improper combustion. Determine the
cause and correct.
7. Inspect the vent system and air intake system,
and ensure that all joints are sealed properly. If
joints need to be resealed, completely remove
existing sealing material, and clean with alcohol.
Apply new sealing material, and re-assemble.
7.2 Appliance Maintenance and
Component Description
Only genuine Laars replacement parts should be used.
Caution
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and
dangerous operation. Verify proper operation after
servicing.
For location of gas train and control components,
see Figures 4, 11 and 9, 12 respectively.
The gas and electric controls on the appliance are
engineered for long life and dependable operation, but
the safety of the equipment depends on their proper
functioning. It is strongly recommended that a
qualified service technician inspect the basic items
listed below every year.
a. Ignition controls
b. Ignitors
c. Water temperature control
d. Automatic gas valve
e. Pressure switches
f. Blowers
7.2.1 Burners
Close main manual gas valve before proceeding.
Checking the burners for debris - Remove the ignitor
inspection panels(s) and ignitor(s) and inspect the
burners through the ignitor hole(s) using a flashlight to
illuminate. If there is any indication of debris on the
burners that are visible, all the burners will need to be
inspected more thoroughly. Remove the screws from
around the front of the air box (large panel from which
the ignitor inspection panel(s) were removed), and
remove the large panel. Remove the gas manifold
assemblies and the burner panels. Inspect the burners.
Clean burners, if necessary, by blowing compressed
air from the outside of the burners into the center of
the burner. A dirty burner may be an indication of
improper combustion or dirty combustion air.
Determine the cause, and correct. Replace the burners
in the reverse order.
7.2.2 Filter
The filter used in the Pennant is washable with an
83% arrestance. Since the filter is washable, it will
only need replacement in very rare cases. If filter
replacement is needed, it should only be replaced with
a factory part. Inspect the air filter. If there is debris on
the air filter, remove it from the filter box, and wash it
with mild soap and water. Ensure that the filter is
completely dry before re-installing, in reverse order.
7.2.3 Gas Valves
The gas valves are designed to operate with
supply pressures of 4-13 inches w.c. (1.0 to 3.2 kPa).
To remove a valve, shut off 120-volt power and
the manual gas shutoff valve. Remove the top front
panel from the unit. Disconnect the wires to the valve.
Disengage the flanged fitting before and after the
valve, and remove the valve. Re-install in reverse
order. Ensure o-rings are properly installed for both
inlet and outlet. Turn on manual gas shutoff valve and
120 volt power and check appliance operation and
tightness of gas valve connections.
7.2.4 Pool Loop High Limit Control
The high limit switch is an automatic reset
switch with an adjustable set point, up to 135°F
(57°C). To replace the switch, shut off the 120-volt
power to the appliance. Remove the cover from the
switch to access the mounting screws. Remove the
screws, and pull the switch off the control panel.
Remove the capillary and bulb from the thermal well
located in the pool loop adjacent to the heater outlet.
Replace in reverse order.
7.2.5 Automatic Reset High Limit Control
An automatic reset high limit is used to limit
heater water from exceeding 200°F. The high limit
switch has an adjustable set point, up to 190°F (88°C).
To replace the switch, shut off the 120-volt power to