HTP EL-80 User manual

120 Braley Rd. P.O. Box 429 East Freetown, MA 02717-0429 www.htproducts.com
LP- 293 REV. 3.29.12
Elite
INSTALLATION
START-UP
MAINTENANCE
PARTS
Elite Models*
EL-80 / 110 / 150 / 220 / 299 / 399
*A suffix of “LP” denotes propane gas
*A suffix of “N” denotes natural gas
NOTICE: HTP reserves the right to make product changes or updates without notice and will not be held liable for
typographical errors in literature.
NOTE TO CONSUMER: PLEASE KEEP ALL INSTRUCTIONS FOR FUTURE REFERENCE.
This manual must only be used by a qualified heating installer/service technician. Read all instructions in this
manual before installing. Perform steps in the order given. Failure to comply could result in substantial property
damage, severe personal injury, or death.

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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
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 neighbor’s phone. Follow the gas supplier’s instructions.
If you cannot reach your gas supplier, call the fire department. Installation and service must be provided
by a qualified installer, service agency, or the gas supplier.

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The following defined terms are used throughout this manual to bring attention to the presence of
hazards of various risk levels, or to important product information.
DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.
WARNING indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.
CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.
CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided,
may result in property damage.
FOREWORD
This manual is intended to be used in conjunction with other literature provided with the boiler. This includes all
related control information. It is important that this manual, all other documents included with this system, and
additional publications including the National Fuel Gas Code, ANSI Z223.1-2002, be reviewed in their entirety
before beginning any work.
Installation should be made in accordance with the regulations of the Authority Having Jurisdiction, local code
authorities, and utility companies which pertain to this type of water heating equipment.
Authority Having Jurisdiction (AHJ) –The Authority Having Jurisdiction may be a federal, state, local
government, or individual such as a fire chief, fire marshal, chief of a fire prevention bureau, labor department or
health department, building official or electrical inspector, or others having statutory authority. In some
circumstances, the property owner or his/her agent assumes the role, and at government installations, the
commanding officer or departmental official may be the AHJ.
NOTE: HTP, Inc. reserves the right to modify product technical specifications and components without prior
notice.
FOR THE INSTALLER
This appliance must be installed by qualified and licensed personnel. The installer should be guided by the
instructions furnished with the boiler, and with local codes and utility company requirements. In the absence of
local codes, preference should be given to the National Fuel Gas Code, ANSI Z223.1-2002.
This manual must only be used by a qualified heating installer/service technician. Read all instructions in this
manual before installing. Perform steps in the order given. Failure to comply could result in substantial property
damage, severe personal injury, or death.

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INSTALLATIONS MUST COMPLY WITH:
Local, state, provincial, and national codes, laws, regulations and ordinances.
The latest version of the National Fuel Gas Code, ANSI Z223.1, from American Gas Association Laboratories,
8501 East Pleasant Valley Road, Cleveland, OH 44131.
In Canada –CGA No. B149 (latest version), from Canadian Gas Association Laboratories, 55 Scarsdale Road,
Don Mills, Ontario, Canada M3B 2R3. Also, Canadian Electrical Code C 22.1, from Canadian Standards
Association, 5060 Spectrum Way, Suite 100, Mississauga, Ontario, Canada L4W 5N6.
Code for the installation of Heat Producing Appliances (latest version), from American Insurance Association, 85
John Street, New York, NY 11038.
The latest version of the National Electrical Code, NFPA No. 70.
NOTE: The gas manifold and controls met safe lighting and other performance criteria when the boiler underwent
tests specified in ANSI Z21.13 –latest edition.
The hydronic supply and return connections of these products are for installation in closed loop systems
ONLY! Use of this product in any manner other than described in this manual may result in premature product
failure, substantial property damage, severe personal injury, or death. Damage or failure of this product (or the
system in which it is installed) due to unauthorized use IS NOT COVERED BY WARRANTY.
TABLE OF CONTENTS
PART 1 –GENERAL SAFETY INFORMATION .......................................................................................................7
A. PRECAUTIONS...................................................................................................................................................................7
B. IMPROPER COMBUSTION................................................................................................................................................8
C. GAS.....................................................................................................................................................................................8
D. WHEN SERVICING THE BOILER ......................................................................................................................................8
E. BOILER WATER .................................................................................................................................................................8
F. BOILER WATER CHEMISTRY*..........................................................................................................................................9
G. FREEZE PROTECTION FLUIDS........................................................................................................................................9
PART 2 –BEFORE YOU START..............................................................................................................................9
A. WHAT’S IN THE BOX .........................................................................................................................................................9
B. HOW BOILER OPERATES...............................................................................................................................................10
C. OPTIONAL EQUIPMENT..................................................................................................................................................11
PART 3 –PREPARE BOILER LOCATION.............................................................................................................12
A. BEFORE LOCATING THE BOILER..................................................................................................................................12
B. LEVELING AND DIMENSIONS.........................................................................................................................................13
C. CLEARANCES FOR SERVICE ACCESS.........................................................................................................................14
D. RESIDENTIAL GARAGE INSTALLATION........................................................................................................................16
E. EXHAUST VENT AND INTAKE AIR VENT.......................................................................................................................17

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F. PREVENT COMBUSTION AIR CONTAMINATION...........................................................................................................17
G. REMOVING A BOILER FROM A COMMON VENT SYSTEM ..........................................................................................18
H. UNCRATING THE BOILER...............................................................................................................................................18
PART 4 –BOILER PIPING......................................................................................................................................19
A. GENERAL PIPING INFORMATION ..................................................................................................................................19
B. RELIEF VALVE .................................................................................................................................................................20
C. BACKFLOW PREVENTER ...............................................................................................................................................20
D. SYSTEM WATER PIPING METHODS..............................................................................................................................20
E. CIRCULATORS.................................................................................................................................................................21
F. HYDRONIC PIPING WITH CIRCULATORS, ZONE VALVES, AND MULTIPLE BOILERS ..............................................22
G. PIPING DETAILS*.............................................................................................................................................................22
H. PIPING INSTALLATION....................................................................................................................................................27
I. CIRCULATOR SIZING........................................................................................................................................................28
J. CHECK/CONTROL WATER CHEMISTRY........................................................................................................................29
K. FILL AND PURGE HEATING SYSTEM ............................................................................................................................31
L. GLYCOL ANTIFREEZE SOLUTIONS ...............................................................................................................................31
M. ZONING WITH ZONE VALVES........................................................................................................................................32
N. ZONING WITH CIRCULATORS........................................................................................................................................32
O. MULTIPLE BOILERS........................................................................................................................................................32
PART 5 –VENTING, COMBUSTION AIR, AND CONDENSATE REMOVAL........................................................33
A. GENERAL .........................................................................................................................................................................33
B. APPROVED MATERIALS FOR EXHAUST AND INTAKE AIR VENTS.............................................................................34
C. REQUIREMENTS FOR INSTALLATION IN CANADA......................................................................................................35
D. EXHAUST VENT AND INTAKE AIR VENT PIPE LOCATION ..........................................................................................36
E. EXHAUST VENT AND INTAKE AIR VENT SIZING..........................................................................................................39
F. LONGER VENT RUNS......................................................................................................................................................40
G. EXHAUST VENT AND INTAKE AIR PIPE INSTALLATION..............................................................................................40
H. SIDEWALL VENTING.......................................................................................................................................................42
I. VERTICAL VENTING .........................................................................................................................................................43
J. HORIZONTAL VENTING...................................................................................................................................................44
K. UNBALANCED FLUE / VERTICAL VENT.........................................................................................................................45
L. VENTING THROUGH AN EXISTING SYSTEM.................................................................................................................46
1. CONCENTRIC VENTING THROUGH AN EXISTING SYSTEM......................................................................................................... 46
2. VENTING AS A CHASE..................................................................................................................................................................... 48
M. INDOOR COMBUSTION AIR INSTALLATION IN CONFINED OR UNCONFINED SPACE.............................................49
PART 6 –GAS PIPING............................................................................................................................................51
A. GAS CONNECTION..........................................................................................................................................................51
B. GAS PIPING......................................................................................................................................................................51

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C. CHECK INLET GAS PRESSURE .....................................................................................................................................52
D. BOILER GAS VALVE........................................................................................................................................................54
PART 7 –FIELD WIRING........................................................................................................................................55
A. INSTALLATION MUST COMPLY WITH:...........................................................................................................................55
B. FIELD WIRING TERMINATIONS......................................................................................................................................55
C. FIELD WIRING..................................................................................................................................................................55
D. LINE VOLTAGE WIRING FOR STANDARD BOILER.......................................................................................................56
E. ALARM CONNECTIONS...................................................................................................................................................56
F. LOW VOLTAGE CONNECTIONS FOR STANDARD BOILER..........................................................................................56
G. THERMOSTAT .................................................................................................................................................................56
H. OUTDOOR SENSOR........................................................................................................................................................57
I. INDIRECT SENSOR...........................................................................................................................................................57
J. OPTIONAL 0-10 VOLT BUILDING CONTROL SIGNAL....................................................................................................57
K. OPTIONAL UL353 LOW WATER CUT-OFF INTERFACE KIT .........................................................................................58
L. WIRING OF CASCADE SYSTEM COMMUNICATION BUS .............................................................................................58
M. CASCADE MASTER PUMP AND SENSOR WIRING ......................................................................................................59
N. CASCADE FOLLOWER PUMP AND SENSOR WIRING..................................................................................................59
PART 8 –START-UP PREPARATION ...................................................................................................................63
A. CHECK / CONTROL WATER CHEMISTRY .....................................................................................................................63
B. CHECK FOR GAS LEAKS ................................................................................................................................................64
C. FREEZE PROTECTION (WHEN USED) ..........................................................................................................................64
D. FILL AND TEST WATER SYSTEM...................................................................................................................................64
E. PURGE AIR FROM WATER SYSTEM..............................................................................................................................65
F. CHECK THERMOSTAT CIRCUIT(S) ................................................................................................................................66
G. CONDENSATE REMOVAL...............................................................................................................................................66
H. FINAL CHECKS BEFORE STARTING BOILER ...............................................................................................................67
I. CASCADE SYSTEM...........................................................................................................................................................67
J. LOCKOUT CONDITION.....................................................................................................................................................68
PART 9 –START-UP PROCEDURE.......................................................................................................................68
A. CONTROL OVERVIEW.....................................................................................................................................................68
B. NAVIGATION OF THE DISPLAY......................................................................................................................................69
C. OPERATING INSTRUCTIONS .........................................................................................................................................69
D. PROGRAMMING BOILER SETTINGS .............................................................................................................................70
E. PROGRAMMING THE SYSTEM SETTING ......................................................................................................................71
F. SYSTEM SETTING PROGRAM NAVIGATION.................................................................................................................71
G. RESETTING THE MAINTENANCE SCHEDULE..............................................................................................................73
PART 10 –START-UP PROCEDURES FOR THE INSTALLER............................................................................74
A. BOILER CONTROL STATUS MENU ................................................................................................................................74

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B. BOILER TEST MODE .......................................................................................................................................................76
C. CASCADE MENU .............................................................................................................................................................76
D. TEST MODE ACCESS......................................................................................................................................................77
PART 11 –TROUBLESHOOTING ..........................................................................................................................77
A. BOILER ERROR CODE....................................................................................................................................................77
B. BOILER ERROR ...............................................................................................................................................................78
C. BOILER FAULT.................................................................................................................................................................78
D. USER INTERFACE DISPLAY...........................................................................................................................................79
PART 12 –MAINTENANCE ....................................................................................................................................84
A. MAINTENANCE PROCEDURES.....................................................................................................................84
B. COMBUSTION CHAMBER COIL CLEANING INSTRUCTIONS FOR BOILER..............................................85
C. CLEANING WATER SIDE OF HEAT EXCHANGER.......................................................................................86
BOILER START-UP REPORT.................................................................................................................................91
MAINTENANCE REPORT.......................................................................................................................................92
MAINTENANCE NOTES..........................................................................................................................................96
HTP CUSTOMER INSTALLATION RECORD FORM.....................................................................................97
PART 1 –GENERAL SAFETY INFORMATION
A. PRECAUTIONS
This appliance is for indoor installations only. Clearance to combustible materials: 0” top, bottom, sides and back.
Left side has all boiler mechanical connections. Front must have room for service, 24” recommended. (A
combustible door or removable panel is acceptable front clearance.) This appliance has been approved for closet
installation. Do not install this appliance directly on carpeting. For installation on combustible flooring. Category IV
vent systems only.
INSTALLER –Read all instructions in this manual before installing. Perform steps in the order given.
USER –This manual is for use only by a qualified heating installer/service technician. Have this boiler
serviced/inspected by a qualified service technician annually.
FAILURE TO ADHERE TO THE GUIDELINES ON THIS PAGE AND HAVE THIS BOILER
SERVICED/INSPECTED ANNUALLY CAN RESULT IN SUBSTANTIAL PROPERTY DAMAGE, SEVERE
PERSONAL INJURY, OR DEATH.
NOTE: When inquiring about service or troubleshooting, reference the model and serial numbers from the boiler
rating label.

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NOTE: If the boiler is exposed to the following, do not operate until all corrective steps have been made by a
qualified serviceman:
1. FIRE
2. DAMAGE
3. WATER
Any claims for damage or shortage in shipment must be filed immediately against the transportation company by
the consignee.
DO NOT USE THIS APPLIANCE IF ANY PART HAS BEEN SUBMERGED IN WATER. Immediately call a
qualified service technician. The appliance MUST BE replaced if it has been submerged. Attempting to operate an
appliance that has been submerged could create numerous harmful conditions, such as a potential gas leakage
causing a fire and/or explosion, or the release of mold, bacteria, or other harmful particulates into the air.
Operating a previously submerged appliance could result in property damage, severe personal injury, or death.
NOTE: Appliance damage due to flood or submersion is considered an Act of God, and IS NOT covered under
product warranty.
Be sure to disconnect electrical power before opening boiler cabinet or performing service. Failure to do so could
result in an electrical shock that could result in property damage, serious personal injury, or death.
Due to the low water content of the boiler, improper sizing of the boiler with regard to heating system load will
result in excessive cycling and accelerated component failure. HTP DOES NOT warrant failures caused by
improperly sized boiler applications. DO NOT oversize the boiler to the system. Modular boiler installations greatly
reduce the likelihood of boiler oversizing.
B. IMPROPER COMBUSTION
C. GAS
Should overheating or gas supply fail to shut off, do not turn off or disconnect electrical supply to the circulator.
Instead, shut off the gas supply at a location external to the appliance.
D. WHEN SERVICING THE BOILER
To avoid electric shock, disconnect electrical supply before performing maintenance.
To avoid severe burns, allow boiler to cool.
E. BOILER WATER
If you have an old system with cast iron radiators, thoroughly flush the system (without boiler connected)
to remove sediment. The high-efficiency heat exchanger can be damaged by build-up or corrosion due to
sediment. HTP recommends a suction strainer in this type of system.
Do not use petroleum-based cleaning or sealing compounds in boiler system. Gaskets and seals in the
system may be damaged, possibly resulting in substantial property damage.
Do not obstruct the flow of combustion and ventilating air. Adequate air must be provided for safe operation.
Failure to keep the vent and combustion air intake clear of ice, snow, or other debris could result in property
damage, serious personal injury, or death.

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Do not use “homemade cures” or “boiler patent medicines”. Substantial property damage, damage to
boiler, and/or serious personal injury may result.
Continual fresh make-up water will reduce boiler life. Mineral buildup in the heat exchanger reduces heat
transfer, overheats the stainless steel heat exchanger, and causes failure. Addition of oxygen from make-
up water can cause internal corrosion in system components. Leaks in the boiler or piping must be
repaired at once.
NOTE: DO NOT add cold make up water to the system when the boiler is hot. Thermal shock can potentially
cause cracks in the heat exchanger. Such damage IS NOT covered by warranty.
F. BOILER WATER CHEMISTRY*
Sodium less than 20mGL.
Water pH between 6.0 and 8.0
oMaintain water pH between 6.0 and 8.0. Check with litmus paper or have it chemically analyzed
by water treatment company.
oIf the pH differs from above, consult local water treatment company for treatment needed.
Hardness less than 7 grains
oConsult local water treatment companies for unusually hard water areas (above 7 grains
hardness).
Chlorine concentration less than 100 ppm
oUsing chlorinated fresh water should be acceptable as levels are typically less than 5 ppm.
oDo not connect the boiler to directly heat swimming pool or spa water.
oDo not fill boiler or operate with water containing chlorine in excess of 100 ppm.
*NOTE: It is recommended to clean heat exchanger at least once a year to prevent lime scale buildup. To
clean the heat exchanger, follow the maintenance procedure in Part 13, Section B of this manual.
Hardness: 7 grains
Chloride levels: 100 ppm
pH levels: 6-8
TDS: 2000 ppm
Sodium: 20 mGL
G. FREEZE PROTECTION FLUIDS
NEVER use automotive or standard glycol antifreeze, or ethylene glycol made for hydronic systems, with this
boiler. Use only inhibited propylene glycol solutions, which are specifically formulated for hydronic systems.
Ethylene glycol is toxic and can attack gaskets and seals used in hydronic systems.
Consider boiler piping and installation when determining boiler location.
NOTE: Damages resulting from incorrect installation or from use of products not approved by HTP, Inc. ARE NOT
covered by warranty.
PART 2 –BEFORE YOU START
A. WHAT’S IN THE BOX
Also included with the boiler:
Temperature and Pressure Gauge (Part #7450-222)

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Pressure Relief Valve (Part #7250P-219 for EL80/110/150, #7350P-065 for EL220/299/399)
Indirect Sensor
Outdoor Sensor
Intake PVC Tee with Screens
Exhaust PVC Coupling with Screens
Outlet Combination Fitting (1” - Part #7450P-134 for EL80/110/150/220, 1.25” - #7450-135 for EL299,
1.5” - #7450-136 for EL399)
Installation Manual
Warranty
CSD-1 Form
H-3 Data Sheet
NAT to LP Conversion Kit (Part #7450P-223) (Included with NAT models)
LP to NAT Conversion Kit (Part #7450P-224) (Included with LP models)
B. HOW BOILER OPERATES
Elite®condensing technology intelligently delivers hydronic heating while maximizing efficiency. Outlined below
are the features of the system and how they operate:
Stainless Steel Heat Exchanger - The highly efficient stainless steel heat exchanger is designed to extract all
available heat from the supply line before it is exhausted.
Modulating Combustion System - The combustion system will modulate the output of the burner during
operation to match the system demand and achieve the control set point while in operation. The set point can
change by internal or external signals which enhance the overall performance of the system.
Control –The integrated control system monitors the system and regulates fan speed to control boiler output.
This allows the boiler to deliver only the amount of heat energy required and nothing more.
The control can be set up to monitor outdoor temperature through an outdoor sensor to regulate boiler set point.
The system can be further enhanced by installing an indirect water heater to provide domestic hot water.
The control can regulate the output of multiple boilers through its cascade system function. The cascade system
is capable of connecting up to eight boilers together in such a way that they function as one boiler system. This
allows for greater turn down ratios and provides systematic control of the multiple boilers in an installation to
minimize downtime and maximize efficiency.
The cascade system works by establishing one boiler as the master and the other connected boilers as followers.
The master boiler requires a sensor to provide feedback on set point temperature in order to adjust heating input
from the connected boilers. Each cascaded boiler will have its own pump to provide maximum flow and control
heat exchanger flow rate.
Text Display and Operational LED Light Indicators –The display allows the user to change system
parameters and monitor system outputs.
Gas Valve –Senses suction from the blower, allowing gas to flow only if powered and combustion air is flowing.
All Metal Integrated Venturi –Controls air and gas flow into the burner.
Burner –Constructed of high grade stainless steel, the burner uses premixed air and gas fuel and provides a
wide range of firing rates.
Spark Ignition –The burner is ignited by applying high voltage through the system spark electrode. This causes
the spark from the electrode to ignite mixed gas off of the burner.

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Supply Water Temperature Sensor –This sensor monitors the boiler outlet water temperature (System Supply).
The control adjusts the boiler firing rate so the supply temperature will match the boiler set point.
Return Water Temperature Sensor –This sensor monitors the boiler return water temperature (System Return).
Flue Sensor –Monitors flue temperature and adjusts firing rate.
Temperature and Pressure Gauge –Allows the user to monitor system temperature and pressure.
Electrical field connections with terminal strips –The electrical cover allows easy access to the line voltage
and low voltage terminals strips which are clearly marked to facilitate wiring of the boiler.
Condensation Collection System –This boiler is a high efficiency appliance, therefore the boiler will produce
condensate. The collection system has a float switch which monitors the condensation level and prevents
condensation from backing up into the combustion system. Inside the collection system there is a built in trap
which seals the combustion system from the connected drain. This condensate should be neutralized to avoid
damage to the drainage system or piping.
Outdoor Sensor –Monitors outdoor temperature and adjusts unit set point to provide greater efficiency.
0-10 Volt Input –Allows Installer to connect a BMS (Building Management System) to control the boiler.
Condensate Flue Check System –The check system prevents exhaust from the heat exchanger from backing
up into cabinet.
Pump Service Mode –Allows manual operation of pumps to commission system and check pump operation.
The Vision II System (Optional) –Allows the user to supply mixed temperatures in up to eight zones. The Vision
II system controls the temperature to each zone by employing three way mixing valves. The Vision II also controls
the output temperature of the boiler to assure accurate temperature delivery to all connected zones.
C. OPTIONAL EQUIPMENT
Below is a list of optional equipment available from HTP. These additional options may be purchased through
your HTP distributor:
Wall Mount Bracket (Part # 7450P-211)
System Sensor (Part # 7250P-324)
Indirect Tank Sensor (Part # 7250P-325)
3" PVC Concentric Vent Kit (Part # KGAVT0601CVT)
3” Stainless Steel Outside Termination Vent Kit (Part # V1000)
4” Stainless Steel Outside Termination Vent Kit (Part # V2000)
6” Stainless Steel Outside Termination Vent Kit (Part # V3000)
3” Polypro Vent Kit (Part # 8400P-001)
3” Polypro Pipe (33’ length Part # 8400P-002, 49.5’ length Part # 8400P-003)
U.L. 353 Compliant Low Water Cut-Off Interface Kit with Manual Reset (Part # 7450P-225)
Manual Reset High Limit (Part # 7450P-217)
Alarm System (Part # 7350P-602) (to monitor any failure)
PC Connection Kit (Part # 7250P-320)
Condensate Neutralizer (Part # 7450P-212 for EL-80/110/150/220/299, Part # 7350P-611 for EL-399)
Flow Switch Kit (Part # 7450P-213 for EL-80/110/150/220, Part # 7450P-214 for EL-299, Part # 7450P-
215 for EL-399)
Vision II (Part # 7250P-322)

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PART 3 –PREPARE BOILER LOCATION
Carefully consider installation when determining boiler location. Please read the entire manual before attempting
installation. Failure to properly take factors such as boiler venting, piping, condensate removal, and wiring into
account before installation could result in wasted time, money, and possible property damage and personal injury.
A. BEFORE LOCATING THE BOILER
Incorrect ambient conditions can lead to damage to the heating system and put safe operation at risk. Ensure that
the boiler installation location adheres to the information included in this manual. Failure to do so could result in
property damage, serious personal injury, or death.
Failure of boiler or components due to incorrect operating conditions IS NOT covered by product warranty.
1. Installation Area (Mechanical Room) Operating Conditions
Ensure ambient temperatures are higher than 32oF/0oC and lower than 104oF/40oC.
Prevent the air from becoming contaminated by the products, places, and conditions listed in this manual,
Part 3, Section F.
Avoid continuously high levels of humidity
Never close existing ventilation openings
The service life of the boiler’s exposed metallic surfaces, such as the casing, as well as internal surfaces, such as
the heat exchanger, are directly influenced by proximity to damp and salty marine environments. In such areas,
higher concentration levels of chlorides from sea spray coupled with relative humidity can lead to degradation of
the heat exchanger and other boiler components. In these environments, boilers must not be installed using direct
vent systems which draw outdoor air for combustion. Such boilers must be installed using room air for
combustion. Indoor air will have a much lower relative humidity and, hence, potential corrosion will be minimized.
This boiler is certified for indoor installations only. Do not install the boiler outdoors. Failure to install this boiler
indoors could result in substantial property damage, severe personal injury, or death.
2. Check for nearby connections to:
System water piping
Venting connections
Gas supply piping
Electrical power
Condensate drain
3. Check area around boiler. Remove any combustible materials, gasoline, and other flammable liquids.
Failure to keep boiler area clear and free of combustible materials, liquids, and vapors can result in substantial
property damage, severe personal injury, or death.

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4. Gas control system components must be protected from dripping water during operation and service.
5. If the boiler is to replace an existing boiler, check for and correct any existing system problems, such as:
System leaks
Location that could cause the system and boiler to freeze and leak.
Incorrectly-sized expansion tank
6. Clean and flush system when reinstalling a boiler.
NOTE: When installing in a zero clearance location, it may not be possible to read or view some product labeling.
It is recommended to make note of the boiler model and serial number.
Do not mount the boiler to a hollow wall. Mount to the studs only. Failure to do so will result in substantial property
damage, and could result in severe personal injury or death.
Use extreme care not to drop the boiler or cause bodily injury while lifting or mounting the boiler onto the optional
wall mount bracket. Failure to do so will result in property damage, and could result in severe personal injury or
death.
Gas conversion should be performed BEFORE the boiler is installed. Carefully follow the gas conversion
instructions when performing the conversion. Failure to do so could result in property damage, severe personal
injury, or death.
B. LEVELING AND DIMENSIONS
In order for the condensate to properly flow out of the
collection system, the area where you locate the boiler
must be level. The boiler comes equipped with
leveling feet. Should you find the floor beneath the
boiler is uneven, adjust the leveling feet with a wrench.
Figure 1 –Leveling

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C. CLEARANCES FOR SERVICE ACCESS
See Figure 2 for recommended service clearances.
If these minimum clearances are not provided, it
may not be possible to service the boiler without
removing it from the space.
Space must be provided with
combustion/ventilation air openings correctly sized
for all other appliances located in the same space
as the boiler. The boiler cover must be securely
fastened to prevent it from drawing air from the
boiler room. This is particularly important if the
boiler is in a room with other appliances. Failure to
comply with the above could result in substantial
property damage, severe personal injury, or death.
MINIMUM CLEARANCES FROM COMBUSTIBLE
MATERIALS
Hot water pipes –at least 1” from combustible materials.
Exhaust vent pipe –at least 1” from combustible materials.
Figure 2 –Recommended Service Clearances

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Figure 3

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Figure 4
D. RESIDENTIAL GARAGE INSTALLATION
PRECAUTIONS
If the boiler is located in a residential garage, per ANSI Z223.1:
Mount the bottom of the boiler a minimum of 18” above the floor of the garage, to ensure the burner and
ignition devices are well off the floor.
Locate or protect the boiler so it cannot be damaged by a moving vehicle.

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E. EXHAUST VENT AND INTAKE AIR VENT
Vents must be properly supported. The boiler intake and exhaust connections are not designed to carry heavy
weight. Vent support brackets must be within 1’ of the boiler and the balance at 4’ intervals. Venting must be
readily accessible for visual inspection for the first 3’ from the boiler.
The boiler is rated ANSI Z21.13 Category IV (pressurized vent, likely to form condensate in the vent), and
requires a special vent system designed for pressurized venting.
You must also install air intake piping from outdoors to the boiler flue adaptor. The resultant installation is
categorized as direct vent (sealed combustion). NOTE: To prevent combustion air contamination, see Table 1 in
this section when considering exhaust vent and intake air vent termination.
Intake and exhaust vents must terminate near each other and may be vented vertically through the roof or out a
side wall. Intake and exhaust venting methods are detailed in the Venting Section. Do not attempt installation
using any other means. Be sure to locate the boiler so intake and exhaust vent piping can be routed through the
building and properly terminated. The air intake and exhaust vent piping lengths, routing and termination method
must all comply with methods and limits given in the venting section.
F. PREVENT COMBUSTION AIR CONTAMINATION
Install intake piping for the boiler as described in the Venting section. Do not terminate exhaust in locations that
can allow contamination of intake air.
Ensure that the intake air will not contain any of the contaminants below. For example, do not pipe intake vent
near a swimming pool. Avoid areas subject to exhaust fumes from laundry facilities. These areas always contain
contaminants. Contaminated air will damage the boiler, resulting in possible substantial property damage, severe
personal injury, or death.
PRODUCTS TO AVOID
AREAS LIKELY TO HAVE CONTAMINANTS
Spray cans containing fluorocarbons
Dry cleaning/laundry areas and establishments
Permanent wave solutions
Swimming pools
Chlorinated waxes/cleaners
Metal fabrication plants
Chlorine-based swimming pool chemicals
Beauty shops
Calcium chloride used for thawing
Refrigeration repair shops
Sodium chloride used for water softening
Photo processing plants
Refrigerant leaks
Auto body shops
Paint or varnish removers
Plastic manufacturing plants
Hydrochloric or Muriatic acid
Furniture refinishing areas and establishments
Cements and glues
New building construction
Antistatic fabric softeners used in clothes dryers
Remodeling areas
Chlorine-type bleaches, laundry detergents, and cleaning solvents
Garages and workshops
Adhesives used to fasten building products
Table 1
NOTE: DAMAGE TO THE BOILER CAUSED BY EXPOSURE TO CORROSIVE VAPORS IS NOT COVERED
BY WARRANTY. (Refer to the limited warranty for complete terms and conditions).

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G. REMOVING A BOILER FROM A COMMON VENT SYSTEM
Do not install the boiler into a common vent with any other appliance. This will cause flue gas spillage or
appliance malfunction, resulting in possible substantial property damage, severe personal injury, or death.
Failure to follow all instructions can result in flue gas
spillage and carbon monoxide emissions, causing
severe personal injury or death.
When removing an existing boiler, the following steps must be
followed.
1. Seal any unused openings in the common venting system.
2. Visually inspect the venting system for proper size and
horizontal pitch to determine if there is blockage, leakage,
corrosion or other deficiencies that could cause an unsafe
condition.
3. If practical, close all building doors, windows and all doors
between the common venting system and other spaces in the
building. Turn on clothes dryers and any appliances not
connected to the common venting system. Turn on any
exhaust fans, such as range hoods and bathroom exhausts, at
maximum speed. Do not operate a summer exhaust fan. Close all fireplace dampers.
4. Place in operation the appliance being inspected. Follow the lighting instructions. Adjust the thermostat so the
appliance will operate continuously.
5. Test for spillage at the draft hood relief opening after 5 minutes of main burner operation. Use the flame of a
match or candle or smoke from a cigarette.
6. After it has been determined that each appliance remaining connected to common venting system properly
vents when tested as outlined, return doors, windows, exhaust fans, fireplace dampers and any other gas burning
appliance to their previous condition of use.
7. Any improper operation of the common venting system should be corrected so the installation conforms to the
National Fuel Gas Code, ANSI Z223.1. 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 G in the National Fuel Gas Code, ANSI Z 223.1.
H. UNCRATING THE BOILER
UNCRATING BOILER –Any claims for damage or shortage in shipment must be filed immediately against the
transportation company by the consignee.
Cold weather handling –If boiler has been stored in a very cold location (below 0oF) before installation, handle
with care until the plastic components come to room temperature.
Figure 5 - CO Warning Label

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Remove all sides of the shipping crate to allow the boiler to be lifted into its installation location. The boiler is also
equipped with leveling feet that can be used to level the boiler properly on an uneven location surface. If surface
flooring is rough, take care when sliding boiler into position, as you could catch the leveling feet and damage the
boiler.
PART 4 –BOILER PIPING
Failure to follow the instructions in this section WILL VOID the warranty and may result in property damage,
serious injury, or death.
The National Standard Plumbing Code, the National Plumbing Code of Canada, and the Uniform Plumbing Code
limit heat transfer fluid pressure to less than the minimum working pressure of the potable water system up to 30
PSI maximum. In addition, the heat transfer fluid must be water or another non-toxic fluid having a toxicity of
Class 1, as listed in Clinical Toxicology of Commercial Products, 5th Edition. Failure to follow this warning could
result in property damage, severe personal injury, or death.
Plumbing of this product should only be done by a qualified, licensed plumber in accordance with all local
plumbing codes. The boiler may be connected to an indirect water heater to supply domestic hot water. HTP
offers indirect water heaters in a wide range of gallon sizes in either stainless steel or glass-lined construction.
A. GENERAL PIPING INFORMATION
The building piping system must meet or exceed the piping requirements in this manual.
Use two wrenches when tightening water piping at the boiler. Use one wrench to prevent the boiler return or
supply line from turning. Failure to prevent piping connections from turning could cause damage to boiler
components.
The control module uses temperature sensors to provide both high limit protection and modulating temperature
control. The control module may also provide low water protection (through the addition of an optional kit) by
sensing the water level in the heat exchanger. An optional flow switch may be installed on the supply of the
system to activate the boiler when there is enough flow. Some codes/jurisdictions may require additional external
controls.
NOTE: The addition of a high temperature limiting device is important if the boiler is to be connected to a
domestic hot water system.
Never use dielectric unions or galvanized steel fittings when connecting to a stainless steel storage tank or boiler.
Failure to follow this instruction can lead to premature failure of the boiler system. Such failures ARE NOT
covered by warranty.

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B. RELIEF VALVE
Connect discharge piping to a safe disposal location following the guidelines in the following statement.
To avoid water damage or scalding due to relief valve operation:
Discharge line must be connected to relief valve outlet and run to a safe place of disposal. Terminate the
discharge line in a manner that will prevent possibility of severe burns or property damage should the
relief valve discharge.
Discharge line must be as short as possible and the same size as the valve discharge connection
throughout its entire length.
Discharge line must pitch downward from the valve and terminate at least 6” above the floor drain,
making discharge clearly visible.
Discharge line shall terminate plain, not threaded, with a material serviceable for temperatures of 375oF
or greater.
Do not pipe discharge to any location where freezing could occur.
No shutoff valve may be installed between the relief valve and boiler or in the discharge line. Do not plug
or place any obstruction in the discharge line.
Test the operation of the relief valve after filling and pressurizing the system by lifting the lever. Make sure
the valve discharges freely. If the valve fails to operate correctly, replace it with a new relief valve.
Test relief valve at least once annually to ensure the waterway is clear. If valve does not operate, turn the
boiler “off” and call a plumber immediately.
Take care whenever operating relief valve to avoid scalding injury or property damage.
For boilers installed with only a pressure relief valve, the separate storage vessel must have a
temperature and pressure relief valve installed. This relief valve shall comply with Relief Valves for Hot
Water Supply Systems, ANSI Z21.22 CSA4.4.
FAILURE TO COMPLY WITH THE ABOVE GUIDELINES COULD RESULT IN FAILURE OF RELIEF VALVE
OPERATION, RESULTING IN POSSIBILITY OF SUBSTANTIAL PROPERTY DAMAGE, SEVERE PERSONAL
INJURY, OR DEATH.
C. BACKFLOW PREVENTER
Use a backflow preventer specifically designed for hydronic boiler installations. This valve should be installed on
the cold water fill supply line per local codes (see Piping Details, Section J).
All piping methods shown in this manual use primary/secondary connection to the boiler loop. This is to avoid the
possibility of inadequate flow through the boiler. For other piping methods, consult your HTP representative or
refer to separate Piping Details, Section J, in this manual.
D. SYSTEM WATER PIPING METHODS
EXPANSION TANK AND MAKE-UP WATER
1. Ensure that the expansion tank is designed and sized to correctly handle system water volume and
temperature.
Expansion tanks must be sized according to total system volume. This includes all length of pipe, all fixtures,
boilers, etc. Failure to properly size system expansion could result in wasted time, money, and possible property
damage, personal injury, or death.