HTP EL-80 Installation and operation manual

120 Braley Rd. P.O. Box 429 East Freetown, MA 02717-0429 www.htproducts.com
LP- 293 REV. 9.2.14
Elite
INSTALLATION
START-UP
MAINTENANCE
PARTS
Models*
EL-80 / 110 / 150 / 220 / 299 / 301 / 399
*A suffix of “LP” denotes propane gas
*A suffix of “N” denotes natural gas
Heat Exchanger Bears the ASME “H” Stamp
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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LP- 293 REV. 9.2.14
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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LP- 293 REV. 9.2.14
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.
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.
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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LP- 293 REV. 9.2.14
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.
NOTICE
IMPORTANT
In accordance with Section 325 (f) (3) of the Energy Policy and Conservation Act, HTP, Inc. has provided this boiler with
multiple features designed to save energy by reducing the boiler water temperature as heating load decreases.
These features include:
A modulating combustion system that adjusts firing rate based on heat demand.
Adjustment of boiler set point based on inferred heat load as determined by an outdoor sensor. The outdoor sensor
is supplied by HTP, Inc. with this boiler.
This boiler does not include a standing pilot.
This boiler is designed and shipped to assure the highest efficiency operation possible. Such high efficiency is
achieved by limiting heating circuit water temperature to 140°F when there is no anticipated heat load, based upon
the outdoor sensor and the Outdoor Reset Curve (sensor response curve) in the boiler software.
This feature may be over-ridden as described below in specific installations:
The boiler control is equipped with an outdoor sensor override for use with building management systems or in
cascaded systems (for systems with total input of 300,000 BTU/hr or greater).
See statement below for an important notice on the use of the override.
IMPORTANT
In accordance with Section 325 (f) (3) of the Energy Policy and Conservation Act, this boiler is equipped with a feature that
saves energy by reducing the boiler water temperature as the heating load decreases. This feature is equipped with an
override which is provided primarily to permit the use of an external energy management system that serves the same
function. THIS OVERRIDE MUST NOT BE USED UNLESS AT LEAST ONE OF THE FOLLOWING CONDITIONS IS TRUE:
An external energy management system is installed that reduces the boiler water temperature as the heating load
decreases.
This boiler is not used for space heating.
This boiler is part of a modular or multiple boiler system having a total input of 300,000 BTU/hr or greater.
This boiler is equipped with a tankless coil.
NOTICE
The CSD-1 ASME Code, Section CW-400 requires that hot water heating and supply boilers have a) a UL 353 temperature control
device, b) at least one (1) temperature-actuated control to shut off the fuel supply when system water reaches a preset operating
temperature, c) a high temperature limit control that prevents the water temperature from exceeding the maximum allowable
temperature by causing a safety shutdown and lockout, and d) its own sensing element and operating switch.
The temperature control system integrated into the 926 control provided with this heating appliance complies with the requirements of
CSD-1 Section CW-400 as a temperature operation control. The control monitors the temperature difference between the inlet and the
outlet sensor, which is affected by boiler water flow. If this temperature difference exceeds 55°F (typically because of low water flow or
very low heat load), the control will reduce the maximum fan speed. If the temperature difference exceeds 60°F, the control will
effectively sense there is little or no water flow or heat load and shut the boiler down. The controller will restart automatically once the
temperature difference has dropped below 55°F and the minimum off time (anti-cycle time) has expired. In addition, if the control
senses that the outlet water temperature has reached 210°F, the boiler is put into a hard lockout and requires manual reset to restart.
TABLE OF CONTENTS
PART 1 –GENERAL SAFETY INFORMATION..........................................................................................................................7
A. PRECAUTIONS..........................................................................................................................................................................7
B. IMPROPER COMBUSTION.......................................................................................................................................................8

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LP- 293 REV. 9.2.14
C. GAS............................................................................................................................................................................................8
D. WHEN SERVICING THE BOILER..............................................................................................................................................8
E. BOILER WATER.........................................................................................................................................................................8
F. BOILER WATER CHEMISTRY* .................................................................................................................................................8
G. FREEZE PROTECTION FLUIDS...............................................................................................................................................9
PART 2 –BEFORE YOU START................................................................................................................................................9
A. WHAT’S IN THE BOX.................................................................................................................................................................9
B. HOW BOILER OPERATES........................................................................................................................................................9
C. OPTIONAL EQUIPMENT.........................................................................................................................................................10
PART 3 –PREPARE BOILER LOCATION ...............................................................................................................................11
A. BEFORE LOCATING THE BOILER .........................................................................................................................................11
B. LEVELING AND DIMENSIONS................................................................................................................................................12
C. CLEARANCES FOR SERVICE ACCESS................................................................................................................................12
D. RESIDENTIAL GARAGE INSTALLATION...............................................................................................................................14
E. EXHAUST VENT AND INTAKE PIPE.......................................................................................................................................14
1. DIRECT VENT INSTALLATION OF EXHAUST VENT AND INTAKE PIPE...............................................................................15
2. INDOOR COMBUSTION AIR INSTALLATION IN CONFINED OR UNCONFINED SPACE......................................................15
F. PREVENT COMBUSTION AIR CONTAMINATION..................................................................................................................15
G. REMOVING A BOILER FROM A COMMON VENT SYSTEM .................................................................................................16
H. UNCRATING THE BOILER......................................................................................................................................................17
PART 4 –BOILER PIPING........................................................................................................................................................17
A. GENERAL PIPING INFORMATION .........................................................................................................................................17
B. RELIEF VALVE ........................................................................................................................................................................17
C. BACKFLOW PREVENTER ......................................................................................................................................................18
D. SYSTEM WATER PIPING METHODS.....................................................................................................................................18
E. CIRCULATORS........................................................................................................................................................................19
F. HYDRONIC PIPING WITH CIRCULATORS, ZONE VALVES, AND MULTIPLE BOILERS......................................................19
G. PIPING DETAILS*....................................................................................................................................................................19
H. PIPING INSTALLATION...........................................................................................................................................................24
I. CIRCULATOR SIZING...............................................................................................................................................................24
J. CHECK/CONTROL WATER CHEMISTRY ...............................................................................................................................26
K. FILL AND PURGE HEATING SYSTEM....................................................................................................................................27
L. GLYCOL ANTIFREEZE SOLUTIONS.......................................................................................................................................27
M. ZONING WITH ZONE VALVES...............................................................................................................................................27
N. ZONING WITH CIRCULATORS...............................................................................................................................................28
O. MULTIPLE BOILERS...............................................................................................................................................................28
PART 5 –VENTING, COMBUSTION AIR, AND CONDENSATE REMOVAL...........................................................................28
A. GENERAL ................................................................................................................................................................................28
B. APPROVED MATERIALS FOR EXHAUST VENT AND INTAKE PIPE....................................................................................29
C. REQUIREMENTS FOR INSTALLATION IN CANADA.............................................................................................................29
D. EXHAUST VENT AND INTAKE PIPE LOCATION...................................................................................................................30

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LP- 293 REV. 9.2.14
E. EXHAUST VENT AND INTAKE PIPE SIZING..........................................................................................................................33
F. LONGER VENT RUNS.............................................................................................................................................................33
G. EXHAUST VENT AND INTAKE PIPE INSTALLATION............................................................................................................34
H. VENTING DRAWINGS.............................................................................................................................................................35
1. DIRECT VENT INSTALLATION OF EXHAUST VENT AND INTAKE PIPE...............................................................................35
2. VENTING THROUGH AN EXISTING SYSTEM ..........................................................................................................................39
3. INDOOR COMBUSTION AIR INSTALLATION IN CONFINED OR UNCONFINED SPACE......................................................41
PART 6 –GAS PIPING..............................................................................................................................................................43
A. GAS CONNECTION.................................................................................................................................................................43
B. GAS PIPING.............................................................................................................................................................................43
C. CHECK INLET GAS PRESSURE.............................................................................................................................................44
D. BOILER GAS VALVE...............................................................................................................................................................45
PART 7 –FIELD WIRING..........................................................................................................................................................46
A. INSTALLATION MUST COMPLY WITH:..................................................................................................................................46
B. FIELD WIRING TERMINATIONS.............................................................................................................................................46
C. FIELD WIRING.........................................................................................................................................................................46
D. LINE VOLTAGE WIRING FOR STANDARD BOILER..............................................................................................................46
E. ALARM CONNECTIONS..........................................................................................................................................................47
F. LOW VOLTAGE CONNECTIONS FOR STANDARD BOILER.................................................................................................47
G. THERMOSTAT ........................................................................................................................................................................47
H. OUTDOOR SENSOR...............................................................................................................................................................47
I. INDIRECT SENSOR..................................................................................................................................................................48
J. OPTIONAL 0-10 VOLT BUILDING CONTROL SIGNAL...........................................................................................................48
K. OPTIONAL UL353 LOW WATER CUT-OFF INTERFACE KIT ................................................................................................48
L. WIRING OF CASCADE SYSTEM COMMUNICATION BUS ....................................................................................................48
M. CASCADE MASTER PUMP AND SENSOR WIRING..............................................................................................................50
N. CASCADE FOLLOWER PUMP AND SENSOR WIRING.........................................................................................................50
PART 8 –START-UP PREPARATION......................................................................................................................................55
A. CHECK / CONTROL WATER CHEMISTRY.............................................................................................................................55
B. CHECK FOR GAS LEAKS .......................................................................................................................................................56
C. FREEZE PROTECTION (WHEN USED)..................................................................................................................................56
D. FILL AND TEST WATER SYSTEM..........................................................................................................................................56
E. PURGE AIR FROM WATER SYSTEM.....................................................................................................................................56
F. CHECK THERMOSTAT CIRCUIT(S) .......................................................................................................................................57
G. CONDENSATE REMOVAL......................................................................................................................................................57
H. FINAL CHECKS BEFORE STARTING BOILER ......................................................................................................................58
I. CASCADE SYSTEM..................................................................................................................................................................58
J. LOCKOUT CONDITION............................................................................................................................................................58
PART 9 –START-UP PROCEDURE.........................................................................................................................................59
A. CONTROL OVERVIEW............................................................................................................................................................59
B. NAVIGATION OF THE DISPLAY .............................................................................................................................................59

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LP- 293 REV. 9.2.14
C. OPERATING INSTRUCTIONS ................................................................................................................................................60
D. PROGRAMMING BOILER SETTINGS.....................................................................................................................................60
E. PROGRAMMING THE SYSTEM SETTING .............................................................................................................................61
F. SYSTEM SETTING PROGRAM NAVIGATION........................................................................................................................61
G. RESETTING THE MAINTENANCE SCHEDULE.....................................................................................................................63
PART 10 –START-UP PROCEDURES FOR THE INSTALLER...............................................................................................64
A. BOILER CONTROL STATUS MENU .......................................................................................................................................64
B. CASCADE MENU.....................................................................................................................................................................66
C. BOILER TEST MODE ACCESS...............................................................................................................................................66
PART 11 –TROUBLESHOOTING ............................................................................................................................................67
A. BOILER ERROR CODE...........................................................................................................................................................67
B. BOILER ERROR ......................................................................................................................................................................67
C. BOILER FAULT........................................................................................................................................................................67
D. USER INTERFACE DISPLAY..................................................................................................................................................68
PART 12 –MAINTENANCE ......................................................................................................................................................73
A. MAINTENANCE PROCEDURES .............................................................................................................................................73
B. COMBUSTION CHAMBER COIL CLEANING INSTRUCTIONS FOR BOILER .......................................................................74
C. CLEANING WATER SIDE OF HEAT EXCHANGER................................................................................................................75
D. MAINTAINING THE CONDENSATE SYSTEM ........................................................................................................................75
BOILER START-UP REPORT...................................................................................................................................................80
MAINTENANCE REPORT.........................................................................................................................................................80
MAINTENANCE NOTES................................................................................................................................................................. 84
HTP CUSTOMER INSTALLATION RECORD FORM.....................................................................................................................85
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.
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.

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LP- 293 REV. 9.2.14
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 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.
Do not obstruct the flow of combustion and ventilating air. Adequate air must be provided for safe operation. Failure to keep the
exhaust vent and intake pipe clear of ice, snow, or other debris could result in property damage, serious personal injury, or death.

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LP- 293 REV. 9.2.14
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 #7250P-211)
Pressure Relief Valve (Part #7250P-080)
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 EL299/301, 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.

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LP- 293 REV. 9.2.14
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.
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)

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Alarm System (Part # 7350P-602) (to monitor any failure)
PC Connection Kit (Part # 7250P-320)
Condensate Neutralizer (Part # 7450P-212 for EL-80/110/150/220/299/301, Part # 7350P-611 for EL-399)
Flow Switch Kit (Part # 7450P-213 for EL-80/110/150/220, Part # 7450P-214 for EL-299/301, Part # 7450P-215 for EL-399)
Vision II (Part # 7250P-322)
NOTE: When using an optional system sensor, pipe insulation must be wrapped around it to improve temperature measurement
accuracy and increase overall system efficiency.
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
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.
MINIMUM CLEARANCES FROM COMBUSTIBLE MATERIALS
Hot water pipes –at least 1” from combustible materials.
Exhaust vent pipe –at least 1” from combustible materials.
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.
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
Figure 2 –Recommended Service Clearances

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LP- 293 REV. 9.2.14
Figure 3 - LP-285-B

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LP- 293 REV. 9.2.14
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.
E. EXHAUST VENT AND INTAKE PIPE
The appliance 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.
NOTE: The venting options described here (and further detailed in the Venting section of this manual) are the lone venting
options approved for this appliance. Failure to vent the appliance in accordance with the provided venting instructions will
void the warranty.

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LP- 293 REV. 9.2.14
Failure to vent the appliance properly will result in serious personal injury or death.
Vents must be properly supported. Appliance exhaust and intake connections are not designed to carry heavy weight. Vent support
brackets must be within 1’ of the appliance and the balance at 4’ intervals. Appliance must be readily accessible for visual inspection for
the first 3’ from the appliance.
1. DIRECT VENT INSTALLATION OF EXHAUST VENT AND INTAKE PIPE
If installing a direct vent option, combustion air must be drawn from the outdoors directly into the appliance intake, and exhaust must
terminate outside. There are three basic direct vent options detailed in this manual: 1. Side Wall Venting, 2. Roof Venting, and 3.
Unbalanced Venting.
Be sure to locate the appliance such that the exhaust vent and intake piping can be routed through the building and properly
terminated. Different vent terminals can be used to simplify and eliminate multiple penetrations in the building structure (see Optional
Equipment in Venting Section). The exhaust vent and intake piping lengths, routing and termination methods must all comply with the
methods and limits given in the Venting section of this manual.
When installing a combustion air intake from outdoors, care must be taken to utilize uncontaminated combustion air. NOTE: To
prevent combustion air contamination, see Table 1.
2. INDOOR COMBUSTION AIR INSTALLATION IN CONFINED OR UNCONFINED SPACE
This appliance requires fresh, uncontaminated air for safe operation and must be installed in a mechanical room where there is
adequate combustion and ventilating air. NOTE: To prevent combustion air contamination, see Table 1.
Combustion air from the indoor space can be used if the space has adequate area or when air is provided through a duct or louver to
supply sufficient combustion air based on the appliance input. Never obstruct the supply of combustion air to the appliance. If the
appliance is installed in areas where indoor air is contaminated (see Table 1) it is imperative that the appliance be installed as direct
vent so that all combustion air is taken directly from the outdoors into the appliance intake connection.
Unconfined space is space with volume greater than 50 cubic feet per 1,000 Btu/hour (4.8 cubic meters per kW) of the total input
rating of all fuel-burning appliances installed in that space. Rooms connected directly to this space, through openings not furnished with
doors, are considered part of the space.
Confined space is space with volume less than 50 cubic feet per 1,000 Btu/hour (4.8 cubic meters per kW) of the total input rating of
all fuel-burning appliances installed in that space. Rooms connected directly to this space, through openings not furnished with doors,
are considered part of the space.
When drawing combustion air from inside a conventionally constructed building to a confined space, such space should be provided
with two permanent openings: one located 6” (15 cm) below the space ceiling, the other 6” (15cm) above the space floor. Each opening
should have a free area of one square inch per 1,000 Btu/hr (22cm2/kW) of the total input of all appliances in the space, but not less
than 100 square inches (645cm2).
If the confined space is within a building of tight construction, air for combustion must be obtained from the outdoors as outlined in the
Venting Section of this manual.
When drawing combustion air from the outside into the mechanical room, care must be taken to provide adequate freeze protection.
Do not attempt to vent this appliance by any means other than those described in this manual. Doing so will void the warranty, and may
result in severe personal injury or death.
Failure to provide an adequate fresh combustion air can cause poisonous flue gases to enter living space, which could result in severe
personal injury or death. To prevent combustion air contamination, see Table 1.
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.

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LP- 293 REV. 9.2.14
Ensure that the intake air will not contain any of the contaminants below. For example, do not pipe intake 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).
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.
Figure 5 - CO Warning Label

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LP- 293 REV. 9.2.14
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.
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.
B. RELIEF VALVE
Connect discharge piping to a safe disposal location following the guidelines in the following statement.
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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LP- 293 REV. 9.2.14
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.
EXPANSION TANK SIZING
EL-80
1.4 Gallons
EL-110
1.7 Gallons
EL-150
2.0 Gallons
EL-220
2.6 Gallons
EL-299 / EL-301
3.1 Gallons
EL-399
3.7 Gallons
Table 2

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LP- 293 REV. 9.2.14
Undersized expansion tanks cause system water to be lost from the relief valve, causing make-up water to be added. Eventual boiler
failure can result due to excessive make-up water addition. SUCH FAILURE IS NOT COVERED BY WARRANTY.
2. The expansion tank must be located as shown in Part 4, Boiler Piping, or following recognized design methods. See expansion tank
manufacturer’s instructions for details.
3. Connect the expansion tank to the air separator only if the air separator is on the suction side of the circulator. Always install the
system fill connection at the same point as the expansion tank connection to the system.
4. Most chilled water systems are piped using a closed type expansion tank.
DO NOT install automatic air vents on closed type expansion tank systems. Air must remain in the system and return to the tank to
provide an air cushion. An automatic air vent would cause air to leave the system, resulting in improper operation of the expansion tank.
DIAPHRAGM (OR BLADDER) EXPANSION TANK
Always install an automatic air vent on top of the air separator to remove residual air from the system.
E. CIRCULATORS
DO NOT use the boiler circulator in any location other than the ones shown in this manual. The boiler circulator location is selected to
ensure adequate flow through the boiler. Failure to comply with this caution could result in unreliable performance and nuisance
shutdowns from insufficient flow.
Sizing Space Heat System Piping
1. See Piping Details in this manual, Section G. In all diagrams, the space heating system is isolated from the boiler loop by the
primary/secondary connection.
2. Size the piping and components in the space heating system using recognized design methods.
F. HYDRONIC PIPING WITH CIRCULATORS, ZONE VALVES, AND MULTIPLE BOILERS
This boiler is designed to function in a closed loop hydronic system. We have included a temperature and pressure gauge that allows
the user to monitor the system pressure and outlet temperature from the boiler. It is important to note that the boiler has a minimal
amount of pressure drop that must be calculated when sizing the circulators. Unless the system has a closed type expansion tank, each
boiler installation must have an air elimination device that will remove air from the system.
Install the boiler so the gas ignition system components are protected from water (dripping, spraying, etc.) Allow clearance for basic
service of boiler circulator, valves and other components.
Observe the minimum 1” clearance around all uninsulated hot water pipes when openings around pipes are not protected by non-
combustible materials.
On a boiler installed above radiation level, some states and local codes require a low water cut off device, which is an optional part
available through HTP (Part # 7450P-225). Check with local codes for additional requirements. If the boiler supplies hot water to
heating coils in air handler units, flow control valves or other devices must be installed to prevent gravity circulation of boiler water in the
coils during the cooling cycle.
Chilled water medium must be piped in parallel with the boiler. Freeze protection for new or existing systems must use glycol that is
specifically formulated for this purpose. Antifreeze must include inhibitors that will prevent the glycol from attacking the metallic system
components. Make certain that the system fluid is checked for the correct glycol concentration and inhibitor level. The system should be
tested at least once a year and as recommended by the producer of the glycol solution. Allowance should be made for the expansion of
the glycol solution in the system piping. Example: 50% by volume glycol solution expands 4.8% in volume for a temperature increase
from 32oF to 180oF, while water expands 3% with the same temperature rise.
G. PIPING DETAILS*
*NOTE: Systems shown are primary/secondary piping systems. These recommended systems have a primary (boiler) loop, and
secondary circuits for heating. The primary loop and secondary circuits have separate circulators. The use of other near boiler piping
configurations could result in improper flow rates, leading to inadvertent boiler high limit shutdowns and poor system performance.

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LP- 293 REV. 9.2.14
Mixing valves are required for the protection of low temperature loops.
NOTE: In piping applications utilizing a single zone, it is recommended that the installer use flow / check valves with weighted seats at
or near the appliance to prevent gravity circulation.
Figure 6 –LP-293-L
NOTES:
1. This drawing is meant to show system piping concept only.
2. A mixing valve is recommended if the DHW temperature is set above 119oF.
3. Install a minimum of 12 diameters of straight pipe upstream of all circulators.
4. Piping shown is Primary/Secondary.
5. System flow (secondary loop) should be greater than the boiler primary loop flow. In all cases, the boiler primary loop flow rate must
be maintained above the minimum flow rates published in this manual.
6. Installations must comply with all local codes.
7. In Massachusetts, a vacuum relief valve must be installed in the cold water line per 248 CMR.