HTP UFT-80W User manual

272 Duchaine Blvd. New Bedford, MA 02745 www.htproducts.com
LP-542 REV. 7.16.15
Universal Fire Tube Boiler
Wall Mount
INSTALLATION
START-UP
MAINTENANCE
PARTS
WARRANTY
Models
UFT- 80W / 100W / 120W / 140W
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.
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 BOILER.
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-542 REV. 7.16.15
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.
NOTICE
SAFETY INSTRUCTIONS
NOTICE is used to address practices not related to personal
injury.
SAFETY INSTRUCTIONS (or equivalent) signs indicate specific safety
related instructions or procedures.
NOTE: Contains additional information important to a procedure.

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LP-542 REV. 7.16.15
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 boiler 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:
Authority Having Jurisdiction, 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.
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-542 REV. 7.16.15
NOTICE
In accordance with Section 325 (f) (3) of the Energy Policy and Conservation Act, HTP, Inc. has provided this appliance with
multiple features designed to save energy by reducing the appliance water temperature as heating load decreases.
These features include:
A modulating combustion system that adjusts firing rate based on heat demand.
Adjustment of appliance set point based on inferred heat load as determined by an outdoor sensor. The outdoor
sensor is supplied by HTP, Inc. with this appliance.
This appliance does not include a standing pilot.
This appliance 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 appliance software.
This feature may be over-ridden as described below in specific installations:
The appliance 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.
In accordance with Section 325 (f) (3) of the Energy Policy and Conservation Act, this appliance is equipped with a feature
that saves energy by reducing the appliance 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 appliance water temperature as the heating load
decreases.
This appliance is not used for space heating.
This appliance is part of a modular or multiple appliance system having a total input of 300,000 BTU/hr or greater.
This appliance 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.
Certain AHJs, locales, and states will require that commercial boiler installations meet the CSD-1 ASME Code, Section CW-400. To
meet this code, HTP, Inc. has integrated a temperature control system into the 926 control provided with this heating boiler. This control
system 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 199°F, the boiler is put into a
hard lockout and requires manual reset to restart.
Installers should review the regulations of the AHJ, local and state code authorities, and utility companies which pertain to this type of
boiler BEFORE performing installation.
TABLE OF CONTENTS
PART 1 –ITEMS SHIPPED WITH THE BOILER ........................................................................................................................7
PART 2 –SAFETY REGULATIONS ...........................................................................................................................................8
A. OPERATION AND INSTALLATION WARNINGS.......................................................................................................................8
B. IMPROPER COMBUSTION .......................................................................................................................................................9
C. GAS............................................................................................................................................................................................9
D. WHEN SERVICING THE BOILER............................................................................................................................................10
E. BOILER SYSTEM.....................................................................................................................................................................10
F. BOILER WATER CHEMISTRY.................................................................................................................................................10
G. FREEZE PROTECTION FLUIDS.............................................................................................................................................10
PART 3 –TECHNICAL SPECIFICATIONS...............................................................................................................................11

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LP-542 REV. 7.16.15
PART 4 –PREPARE BOILER LOCATION ...............................................................................................................................14
A. UNCRATING THE BOILER......................................................................................................................................................14
B. BEFORE LOCATING THE BOILER .........................................................................................................................................15
C. LEVELING................................................................................................................................................................................16
D. CLEARANCES FOR SERVICE ACCESS................................................................................................................................16
E. RESIDENTIAL GARAGE, CLOSET, AND ALCOVE INSTALLATIONS....................................................................................16
F. EXHAUST VENT AND INTAKE PIPE.......................................................................................................................................17
G. PREVENT COMBUSTION AIR CONTAMINATION.................................................................................................................17
H. REMOVING A BOILER FROM A COMMON VENT SYSTEM..................................................................................................17
I. WALL-MOUNTING THE BOILER ..............................................................................................................................................18
PART 5 –VENTING...................................................................................................................................................................19
A. INTAKE PIPE AND EXHAUST VENT GUIDELINES................................................................................................................19
B. APPROVED VENT MATERIALS..............................................................................................................................................21
C. ALLOWED COMBINED VENT LENGTHS...............................................................................................................................21
D. TIGHTENING BOILER COLLAR TO EXHAUST VENT AND INTAKE PIPE............................................................................22
E. VENT TERMINATION ..............................................................................................................................................................23
1. Two Pipe Roof and Sidewall Vent Terminations.....................................................................................................................23
2. Direct Vent, Optional Horizontal and Vertical Vent Kits.........................................................................................................24
3. Snorkel Venting .........................................................................................................................................................................25
4. Screen Installation.....................................................................................................................................................................26
PART 6 –INSTALL THE CONDENSATE DRAIN.....................................................................................................................26
PART 7 –GAS PIPING..............................................................................................................................................................27
A. ADDITIONAL PRECAUTION FOR EXCESS FLOW VALVE (EFV) .........................................................................................28
B. GAS PIPE SIZING TABLES.....................................................................................................................................................28
1. Gas Pipe Sizing..........................................................................................................................................................................28
2. Natural Gas Pipe Sizing ............................................................................................................................................................28
3. LP (Liquid Propane) Gas Pipe Sizing.......................................................................................................................................28
C. GAS CONNECTION REQUIREMENTS...................................................................................................................................29
PART 8 –WATER PIPING ........................................................................................................................................................30
A. GENERAL PLUMBING CONNECTION GUIDELINES.............................................................................................................30
B. BACKFLOW PREVENTER.......................................................................................................................................................31
C. CENTRAL HEATING PIPING SYSTEM WATER PIPING METHODS.....................................................................................31
D. CIRCULATOR SIZING.............................................................................................................................................................31
E. CH PRESSURE RELIEF VALVE..............................................................................................................................................37
F. BUILT-IN LOW WATER CUT-OFF (LWCO).............................................................................................................................37
G. OPTIONAL EXTERNAL UL353 MANUAL RESET LOW WATER CUT-OFF (LWCO) INTERFACE KIT .................................37
PART 9 –CONNECT ELECTRICAL POWER / INITIAL STARTUP .........................................................................................38
A. GENERAL OPERATING CONDITIONS...................................................................................................................................38
B. WIRING INFORMATION..........................................................................................................................................................38
C. DIP SWITCHES .......................................................................................................................................................................39

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PART 10 –OPERATING SYSTEM INSTRUCTIONS................................................................................................................44
A. CONTROL PANEL ...................................................................................................................................................................44
B. LCD DISPLAY DESCRIPTIONS ..............................................................................................................................................44
C. START-UP SEQUENCE ..........................................................................................................................................................44
D. CHANGING THE CH SET-POINT............................................................................................................................................45
E. CHANGING THE TIME.............................................................................................................................................................45
F. STATUS DISPLAY MODE........................................................................................................................................................46
G. INSTALLER MODE..................................................................................................................................................................47
H. ERROR MODE.........................................................................................................................................................................49
I. ERROR TREE ANALYSIS.........................................................................................................................................................53
1. FLAME DETECTION...................................................................................................................................................................53
2. GAS DETECTION ....................................................................................................................................................................... 53
3. APS / BURNER OVERHEAT LIMIT / CONDENSATE BLOCK SWITCH...................................................................................54
4. STORAGE / OP / CH OVERHEAT / EXHAUST OVERHEAT SENSORS ..................................................................................54
J. OUTDOOR TEMPERATURE MODE (OPTIONAL)...................................................................................................................54
K. 0-10 VOLT INPUT ....................................................................................................................................................................55
PART 11 –START-UP PREPARATION....................................................................................................................................56
A. BOILER WATER CHEMISTRY ................................................................................................................................................56
B. FREEZE PROTECTION FLUIDS.............................................................................................................................................57
C. CHECK FOR GAS LEAKS.......................................................................................................................................................57
D. FILL AND TEST WATER SYSTEM..........................................................................................................................................57
E. PURGE AIR FROM SYSTEM...................................................................................................................................................58
F. CHECK THERMOSTAT CIRCUIT(S) .......................................................................................................................................59
G. CONDENSATE REMOVAL......................................................................................................................................................59
H. FINAL CHECKS BEFORE STARTING BOILER ......................................................................................................................59
I. ADJUSTING GAS PRESSURE AT THE BOILER......................................................................................................................59
J. SETTING AND VERIFYING THE COMBUSTION SETTING....................................................................................................60
PART 12 –INSTALLATION AND START-UP CHECKLIST......................................................................................................61
PART 13 –TROUBLESHOOTING ............................................................................................................................................63
PART 14 –ANNUAL MAINTENANCE PROCEDURES............................................................................................................63
REPLACEMENT PARTS ................................................................................................................................................................66
UFT Boiler Limited Warranty ........................................................................................................................................................70
START-UP REPORT.......................................................................................................................................................................72
MAINTENANCE REPORT ..............................................................................................................................................................73
MAINTENANCE NOTES.................................................................................................................................................................76
HTP CUSTOMER INSTALLATION RECORD FORM.....................................................................................................................77

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LP-542 REV. 7.16.15
PART 1 –ITEMS SHIPPED WITH THE BOILER
ITEM
DESCRIPTION
QUANTITY
Universal Fire Tube Boiler
UFT-W
1
H-2 Form, User, and Installation
Manuals
1 Each
Condensate Hose
(Part # 7855P-089)
1
Anchors and Wall Mounting
Bracket
(Part # 7850P-084)
4
Outdoor Sensor with
Screws and Anchors
(Part # 7855P-084)
1
Spare Parts Kit
(Gaskets and O-Rings)
(Part # 7855P-383)
1
30 PSI Pressure Relief Valve
(Part # 7855P-077)
1
1 ¼” X 1 ¼” X ¾” Tee (steel)
(Part # 7855P-313),
3/4" Street Elbow (steel)
(Part # 7350P-084)
1
Automatic Air Vent
(Part # 7855P-063)
1
3” CPVC
(Part # 7855P-101)
6” Length
Vent Screens (3”)
(Part # 7855P-085)
2 Screens
Table 1 –Items Included with the Boiler

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LP-542 REV. 7.16.15
OPTIONAL EQUIPMENT
Below is a list of optional equipment available from HTP. These additional options may be purchased through your HTP distributor:
System Sensor (Part # 7250P-324)
Indirect Tank Sensor (Part # 7250P-325)
2" PVC Concentric Vent Kit (Part # KGAVT0501CVT)
3" PVC Concentric Vent Kit (Part # KGAVT0601CVT)
2” Stainless Steel Outside Termination Vent Kit (Part # V500)
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)
Condensate Neutralizer (Part # 7450P-212)
Condensate Removal Pump (Part # 554200)
Communication Cable (Part # 7850P-093)
2” Vent Screens (Two Screens) (Part # 7850P-088)
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 2 –SAFETY REGULATIONS
A. OPERATION AND INSTALLATION WARNINGS
To avoid serious injury or death, read, understand, and follow all the precautions listed here.
Vapors from flammable liquids will explode and can cause a fire, resulting in personal injury or death. The boiler has a burner that can
come on at any time and ignite vapors. DO NOT use or store flammable liquids around the boiler.
Improper venting can cause a build-up of carbon monoxide. Breathing carbon monoxide can result in brain damage or death. DO NOT
operate the boiler unless it is properly vented to the outside and has an adequate fresh air supply for safe operation. Inspect the
exterior exhaust gas outlet port and fresh air inlet port on a regular basis to ensure they are functioning properly.
A concentration of carbon monoxide as small as .04% (400 parts per million) in the air can be fatal. When making high fire or low fire
adjustments, CO levels must be monitored using a flue gas analyzer such that a CO level of no more than 400 ppm is exceeded at any
time during operation.
Adjusting the “low fire offset” on the gas valve in even small increments can result in a significant increase in CO concentration. To
avoid serious injury or death, DO NOT make any adjustments to the gas valve without monitoring the exhaust gases with a fully
functional and calibrated flue gas analyzer.
Failure to follow these statements will result in property damage, severe personal injury, or death.
This boiler must be installed by a licensed plumber, licensed gas fitter, and/or professional service technician. Improper installation
and/or operation can cause a potentially hazardous situation, which, if not avoided, could result in serious injury or death, and will void
the warranty.
HTP, Inc. cannot anticipate every circumstance that might involve a potential hazard. Each installation has its own specialized
characteristics, requirements, and possible hazards. Therefore, all possible incidents are not included in these warnings. Proper and
safe installation, operation, and service are the responsibility of the professional service technician.
Proper care of the boiler is the user’s responsibility. Ensure the user carefully reads and understands the User’s Information Manual
before operating and maintaining the boiler.
Make sure the user knows the location of the gas shut-off valve and how to operate it. Immediately close the gas shut-off valve if the
boiler is subjected to fire, overheating, flood, physical damage, or any other damaging condition that might affect the operation of the
unit. Have the boiler checked by a qualified technician before resuming operation.
Do not power up the unit unless the gas and water supply valves are fully opened. Make sure the fresh air intake port and exhaust gas
port are open and functional.
No one but a professional service technician should attempt to install, service, or repair this boiler. There are no serviceable parts which
can be changed by the user / owner. User / Owner: Contact the original professional service technician if the boiler needs repair or
maintenance. If the original technician is unavailable, ask your gas supplier for a list of qualified service providers.
Keep the area around the boiler clean and free of all materials that can burn. DO NOT store or place gasoline, oils, spray paint, or other
flammable products near the boiler.
DO NOT use spray paint, hair spray, or any other flammable spray near the boiler or near the exterior fresh air intake port. DO NOT
place any items in or around the exterior exhaust gas outlet port and/or fresh air inlet port that could restrict or block the flow in or out of
the vent system.

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LP-542 REV. 7.16.15
DO NOT store or place newspapers, laundry, or other combustible items near the boiler or the exterior exhaust gas outlet and/or fresh
air inlet port.
The owner should inspect the system monthly for damage, water stains, signs of rust, corrosion, and exhaust vent and air intake
blockage. If inspection of the unit shows signs of damage, the boiler should be shut off until the problem is repaired by a qualified
technician.
After installation, all boiler safety devices should be tested.
This boiler is certified for indoor installations only. The boiler consists of gas ignition system components which must be protected from
water (dripping, spraying, etc.) during operation and service. Carefully consider installation location and the placement of critical
components (circulators, condensate neutralizers, etc.) before installing the boiler.
DO NOT allow children to operate this unit. DO NOT use this unit if it does not appear to be operating correctly. A qualified technician
should service and inspect the boiler annually.
If the boiler is exposed to the following, do not operate until all corrective steps have been made by a qualified service technician:
1. FIRE
2. DAMAGE
3. WATER
This boiler is equipped with a three prong plug. It should only be plugged directly into a properly grounded three prong receptacle. DO
NOT remove the ground plug from the plug.
DO NOT alter or modify the boiler or boiler controls. This can be dangerous and WILL VOID the warranty.
Failure to follow these statements could result in property damage, severe personal injury, or death.
NOTICE
Any claims for damage or shortage in shipment must be filed immediately against the transportation company by the consignee.
This boiler provides a overheat shutdown limit. In the event the boiler water exceeds the set point of the control limit, the cutoff will trip
and the boiler will shut down. Certain local codes require additional temperature limits. In addition, certain types of systems may
operate at temperatures below the minimum set point of the limit provided with the boiler. Contact a qualified service technician for
additional overheat controls.
NOTE: When inquiring about service or troubleshooting, reference the model and serial numbers from the appliance rating label.
DO NOT USE THIS BOILER IF ANY PART HAS BEEN SUBMERGED IN WATER. Immediately call a qualified service technician. The
boiler MUST BE replaced if it has been submerged. Attempting to operate a boiler 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 boiler could result in property damage, severe personal injury, or death.
NOTE: Boiler 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. Label all wires while performing service to
ensure proper re-wiring of the boiler. Wiring errors can cause improper or dangerous operation. Failure to do so could result in an
electrical shock, improper boiler operation, 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
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.
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 boiler.

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LP-542 REV. 7.16.15
D. WHEN SERVICING THE BOILER
To avoid electric shock, disconnect electrical supply before performing
maintenance.
To avoid severe burns, allow boiler to cool.
Do not use petroleum-based cleaning or sealing compounds in a boiler
system. Gaskets and seals in the system may be damaged, possibly
resulting in substantial property damage.
Do not use “homemade cures” or “patent medicines”. Substantial
property damage, damage to boiler, and/or serious personal injury may
result.
Always verify proper operation after servicing the boiler.
E. BOILER SYSTEM
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
all systems.
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.
F. BOILER WATER CHEMISTRY
Sodium less than 20mGL.
Water pH between 6 and 8
oMaintain water pH between 6 and 8. 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.
ACIDITY
6 to 8 pH
CONDUCTIVITY
Less than 400 uS/cm at 25oC
CHLORIDE
Less than 100 ppm
IRON
Less than 0.5 mg/L
COPPER
Less than 0.1 mg/L
SODIUM
Less than 20 mg/L
HARDNESS
Less than 7 Grains
Table 2 –Water Quality Requirements
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.

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LP-542 REV. 7.16.15
PART 3 –TECHNICAL SPECIFICATIONS
MODEL
UFT-80W
UFT-100W
UFT-120W
UFT-140W
Installation
Indoor, Wall Hung, Fully Condensing
Minimum / Maximum Input
(Btu/Hr)
8,000 / 80,000
10,000 / 100,000
12,000 / 120,000
14,000 / 140,000
Flue System
Sealed Combustion Direct Vent
Vent Run
2” (50 feet), 3” (100 feet), Schedule 40 PVC, CPVC, PP
Weight (lbs)
90
100
Gas Supply
Pressure
NG
3.5” to 14” WC
LP
3.5” to 14” WC
Power Supply
Main Supply
120V 60 Hz / 6a
Maximum
Power
Consumption
160W
General Operating Conditions
Temperature
Ambient Temperature Range: 33 –104oF (0.6 –40oC)
Operating Relative Humidity: Up to 90% at 140oF (40oC)
Shipping and Storage Temperature Range: -4 –176oF (-20 –80oC)
Input Ratings
Power Supply and Communication (CN4): 14V DC
Ignition System
Direct Electronic Ignition / Automatic Flame Sensing
Burner System
Premixed Fuel Modulation Metal Fiber Infrared
Gas Valve System
Combination Modulating (Current Proportional)
Internal Pipe Material
Copper
Dimensions
W 17.5” – H 34” – D 15.4”
Boiler Heat Exchanger Capacity
3 Gallons
Main Controller / Control Panel
NGTB-900C / P-950EH
Water Pressure
Min 15 –Max 30 PSI
Connection
Sizes
Space Heating
Supply /
Return
1 ¼” NPT
Gas Inlet
¾” NPT
Materials
Cabinet
Painted Cold Rolled Carbon Steel
Heat
Exchanger
Heat Exchanger: Stainless Steel
Safety Devices
Optical Flame Sensor, Burner Plate High Limit (392oF), Water Temperature High Limit Sensor
(200oF), Gas Leak Detection Sensor (Detects Natural Gas or Propane), Freeze Protection (Three
Stage Operation - Activates at 46oF –See Freeze Protection in Installer Menu for Details),
Exhaust Temperature High Limit Sensor (190oF), Blocked Flue Switch, Condensate Switch, Built-
In Low Water Cut-Off Probe
Table 3 –Technical Specifications

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LP-542 REV. 7.16.15
Figure 1 –UFT Specifications and Dimensions
DESCRIPTION
DIAMETER
A
CH Supply Adapter
1 ¼”
B
CH Return Adapter
1 ¼”
C
Gas Inlet Adapter
¾”
D
Condensate Adapter
½”
E
Intake Pipe Connection
3”
F
Exhaust Vent Connection
3”
MODEL
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
80W
100W
17.5
28.75
34
4.7
7.3
9.1
2.4
5.8
11.7
14.9
9.6
2.8
2.1
2.7
10.7
14.1
2.1
15.4
120W
140W
Table 4 –UFT Specifications

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LP-542 REV. 7.16.15
Figure 2 –UFT Components (All Models)
NUMBER
COMPONENT DESCRIPTION
NUMBER
COMPONENT DESCRIPTION
1
Intake Pipe Adapter
17
CH Bottom Return Adapter
2
CH Top Supply Adapter
18
Condensate Trap
3
Air / Gas Mixing Pipe
19
Condensate Adapter
4
Internal Gas Piping
20
Condensate Air Pressure Switch
5
Gas Valve
21
Low Voltage Terminal Block
6
Exhaust Duct
22
CH Return Pipe
7
Main PCB
23
Heat Exchanger
8
Optical Flame Detection Sensor
24
Ignition Transformer
9
Control Panel CH Supply Pipe
25
Flame viewing window
10
Internal Gas Piping
26
Burner Overheat Switch
11
Manual ON/OFF Power Switch
27
Ignitor rod
12
High Voltage Terminal Block
28
BLDC Fan
13
CH Supply Pipe
29
Air Pressure Switch
14
Gas Inlet Adapter
30
CH Supply Adapter
15
CH Bottom Supply Adapter
31
Exhaust Vent Adapter
16
CH Pressure Gauge
32
Automatic Air Vent
Table 5 –UFT Component List
How the Boiler Operates
UFT 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 316L stainless steel fire tube heat exchanger with internal aluminum is designed
to extract all available heat from the combustion process and pass it into heat transfer fluid. The stainless steel construction provides
protection for longer service life. The heat exchanger offers greater water content, providing lower system pressure and greater overall
system efficiency.
10 to 1 Modulating Combustion System - The combustion system is specially designed to provide very high turn down. This
combustion system will modulate the burner output to very low levels to match the system demand and achieve better overall control of
the heating system for maximum efficiency and reliability.
Control –The integrated control system monitors the system and responds to internal and external signals to regulate fan speed and
control boiler output. This allows the boiler to deliver only the amount of heat energy required and nothing more.

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LP-542 REV. 7.16.15
The control can be set up to monitor outdoor temperature through an outdoor sensor to regulate boiler set point temperature, increasing
overall system efficiency while providing great comfort. 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 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 output from the connected boilers. Through the use of multiple UFT boilers cascaded systems offer greater system
turndown and redundancy.
Electronic LCD Display –The high resolution display allows the user to monitor boiler functions. The display also provides the means
to program the system parameters to maximize the efficiency of the system design.
Combustion System (Blower –Gas Valve –Mixer –Burner –Spark Ignition) –The highly efficient spark ignition combustion system
uses a variable speed blower to adjust combustion as the system requires more or less energy. The negative regulated gas valve
provides only the amount of fuel required to ensure clean combustion. The mixer accurately regulates the combination of gas and air
throughout the modulating range to ensure high reliability. The burner is constructed of durable ceramic metal fiber for long service life.
Boiler Sensors (Return –Supply –Flue - Outdoor) - Sensors provide highly accurate temperature monitoring to assure accurate
system control. These sensor inputs can be monitored through the boiler control system and display.
Pressure Gauge –Allows the user to monitor system pressure.
System Safeties –The boiler is provided with many safety features to ensure reliable and safe operation. Each safety is connected to
the boiler control. The boiler will alert the user if an unsafe condition occurs and needs to be addressed. The following are provided
safeties: Flue Pressure Switch (monitors flue pressure), Burner High Limit (monitors burner plate temperature), High Limit Water Switch
(monitors boiler water temperature), Low Water Sensor (monitors water level in the heat exchanger), optic flame sensor (monitors flame
quality), Flue Sensor (monitors flue temperature), Condensate Pressure Switch (monitors pressure to ensure condensation does not
back up into boiler).
Manual Air Vent –Each boiler is equipped with an air vent to discharge air from the system during start–up.
Intake and Exhaust Adapters –The boiler is equipped with adapters to ease connection to the vent system. The adapters are
provided with clamps and seals to secure field supplied piping, and test ports to ease monitoring of the combustion system. Each boiler
is supplied with a 6 inch piece of CPVC that must be connected into the exhaust vent adapter.
Boiler 1 ¼” Inlet and 1 ¼” Outlet Connection –Boilers are equipped with both top and bottom piping connections for greater
installation flexibility.
Gas Connection –The boiler is equipped with a ¾” gas connection to connect the incoming gas supply.
Field Wiring and Power Switch –Each boiler is supplied with a power switch to cut off power. The boiler is also equipped with two
front mounted terminal strips. These terminal strips are separated into low and line voltage to ease system wiring.
Condensate Trap and Hose Assembly –Each boiler has a built-in condensate trap to control the discharge of condensate produced
by the boiler during normal operation. A corrugated condensate hose is also provided to ensure proper drainage of condensate into the
pump or drain.
Low Water Cut Off Probe –LWCO is provide with each boiler to assure the boiler has adequate water level to eliminate overheating
and even damaging the boiler heat exchanger .
Pump Service Mode –Allows manual operation of pumps to commission system and check pump operation.
PART 4 –PREPARE BOILER LOCATION
A. 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.

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LP-542 REV. 7.16.15
Remove all sides of the shipping crate to allow the boiler to be lifted into its installation 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.
B. 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.
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
Locate the boiler where any leakage from the relief valve, related piping, tank, or connections will not result in damage to surrounding
areas or lower floors of the building. The boiler should be located near a floor drain, or installed in an adequately drained drain pan.
HTP WILL NOT be held liable for leakage damages.
To conserve water and energy, insulate all water piping, especially the hot and recirculation water lines.
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.
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

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LP-542 REV. 7.16.15
6. Clean and flush system when reinstalling an 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.
C. LEVELING
D. CLEARANCES FOR SERVICE ACCESS
See Figure 3 and Table 6 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 boilers 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 boilers. Failure to comply
with the above could result in substantial property damage, severe personal
injury, or death.
MINIMUM CLEARANCES
Installation Clearances from Non-
Combustibles / Combustibles
Recommended Service and Proper
Operation Clearances
Top
18 in. (45.7 cm)
Back
0 in. (0 cm)
Bottom
12 in. (30.45 cm)
Front
24 in. (60.9 cm)
Right Side
3 in. (7.6 cm)
Left Side
Table 6 –Minimum Installation and Service Clearances
NOTE: For closet installations, a combustible door or removable panel is acceptable
front clearance. A 3” minimum clearance must be provided from the boiler front cover to the removable panel or combustible door.
MINIMUM CLEARANCES FROM COMBUSTIBLE MATERIALS
Hot water pipes –at least 1” from combustible materials.
Exhaust vent pipe –at least 1” from combustible materials.
Always take future maintenance into consideration when locating the boiler. If the boiler is located in an installation location with limited
clearances, it may be necessary to remove the boiler from the space to perform maintenance. Failure to consider maintenance when
determining installation location could result in property damage.
E. RESIDENTIAL GARAGE, CLOSET, AND ALCOVE INSTALLATIONS
Check with your local Authority Having Jurisdiction for requirements when installing boiler in a garage, closet, or alcove. 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.
PRECAUTIONS
If the boiler is located in a residential garage, it should be installed per the latest edition of the National Fuel Gas Code, ANSI Z223.1,
and CGA-B149 Installation Code in Canada.
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.
In order for the condensate to properly flow out of the collection system, the boiler must be installed level. Failure to ensure the boiler is
installed level will result in improper boiler operation.
Figure 3 –Minimum Service Clearances

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LP-542 REV. 7.16.15
For closet or alcove installations, a two pipe venting system must be used. Failure to follow this warning could result in substantial
property damage, severe personal injury, or death.
The space must be provided with correctly sized combustion/ventilation air openings for all other boilers located in the space with the
boiler. Do not install the boiler in an attic. Failure to comply with these warnings could result in substantial property damage, severe
personal injury, or death.
F. EXHAUST VENT AND INTAKE PIPE
Vents must be properly supported. The boiler exhaust and intake 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 7 in this section when considering exhaust vent and intake pipe
termination.
Exhaust vent and intake pipe may be vented vertically through the roof or out a side wall. Venting methods are detailed in the Venting
Section. Do not attempt installation using any other means. Be sure to locate the boiler so exhaust vent and intake piping can be routed
through the building and properly terminated. Exhaust vent and intake piping lengths, routing, and termination method must comply with
methods and limits given in the venting section.
G. 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 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 7
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).
H. REMOVING A BOILER FROM A COMMON VENT SYSTEM
Do not install the boiler into a common vent with any other boiler. This will cause flue gas spillage or boiler malfunction, resulting in
possible substantial property damage, severe personal injury, or death.

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LP-542 REV. 7.16.15
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 boilers 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 boiler being inspected. Follow the lighting
instructions. Adjust the thermostat so the boiler 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 boiler remaining connected to common venting system properly vents when tested as
outlined, return doors, windows, exhaust fans, fireplace dampers and any other gas burning boiler 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.
I. WALL-MOUNTING THE BOILER
The boiler must be installed on a wall that can bear its weight (more than 110 lbs. when fully plumbed and full of water). Installing the
boiler on a wall which cannot support its weight could result in property damage, personal injury, or death.
The boiler may be installed on any suitable internal wall (suitable sound-proofing may be required when installing onto a stud partition
wall).
This boiler is too heavy for one person to lift. It is highly recommended to install the boiler with two people. Use caution as to not drop
the boiler, which could damage the boiler and cause property damage and/or severe personal injury. Verify that the boiler is properly
and securely mounted before leaving unsupervised. Failure to comply with the above and properly mount the boiler could result in
substantial property damage, severe personal injury, or death.
This wall mounting system is not seismic rated and should not be applied as such. Failure to comply with the above and properly mount
the boiler could result in substantial property damage, severe personal injury, or death.
POSITIONING THE BOILER ON THE WALL
1. Attach the wall bracket on the location where you want to install the boiler. Ensure it is level and on stud (16” centers) before
proceeding.
2. Mark the four drill holes with a pencil or marker. Remove the wall bracket.
3. Drill four (4) holes using a 5/32 drill bit at the marked hole locations.
4. Mount the wall bracket to the wall with the four (4) included anchor bolts. Ensure the mounted bracket is level. See Figure 5A.
5. Align the boiler bracket grooves on the back of the boiler with the tongues on the wall bracket and hang the boiler on the
bracket. See Figure 5B.
Figure 4 - CO Warning Label

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LP-542 REV. 7.16.15
Figure 5 –Wall Mounting the Boiler
PART 5 –VENTING
Vent this boiler in accordance with these instructions. Failure to do so will result in property damage, severe personal injury, or death.
DO NOT mix vent systems or materials unless specifically told to do so in this manual.
DO NOT thermally insulate the exhaust vent or intake pipes.
DO NOT use an electric damper, vent damper, or draft hood with this boiler.
DO NOT locate the exhaust vent or intake pipe terminations where exposed to prevailing winds.
Moisture will be produced by the exhaust vent. Take precautions when determining exhaust vent termination. Moisture may fall from the
vent termination to the ground and turn to ice in freezing conditions. Moisture or ice can produce a hazardous condition.
Exhaust condensate is acidic, and could deteriorate the surface below the exhaust vent termination. Ensure this surface is in good
repair (sealed, painted, etc.) to prevent deterioration.
Pitch the exhaust vent pipe ¼” back to the boiler. This ensures that condensate in the exhaust vent returns to the boiler and drains
properly.
For closet and alcove installations: CPVC, polypropylene, or stainless steel venting material MUST BE USED. Failure to follow this
statement could result in product damage, severe personal injury, or death.
Failure to follow these instructions could result in property damage, severe personal injury, or death.
A. INTAKE PIPE AND EXHAUST VENT GUIDELINES
1. Vent system must be installed in accordance with local codes, or, in absence of local codes, the National Fuel Gas Code, ANSI
Z223.1 / NFPA 54 and/or CSA B149.1, Natural Gas and Propane Installation Code.
2. For installation in Canada, installer supplied plastic vent piping must comply with CAN/CGA B149.1 and be certified to the
Standard for Type BH Gas Venting Systems, ULC-S636. Components of this listed system must not be interchanged with other vent
systems or unlisted pipes or fittings. All plastic components and specified primers and glues must be from a single system manufacturer
and must not be intermixed with another system manufacturer’s products. Clean and dry all applicable surfaces before applying
cement.
3. This boiler is designed to be installed as a direct vent (sealed combustion) type. Combustion air must be supplied directly from the
outdoors to the burner, and the flue (exhaust) gases should be vented directly to the outdoors through the wall or roof.
4. This boiler uses 2” or 3” diameter pipe for exhaust vent and intake pipe. It is important to ensure an airtight seal from the boiler collar
to the vent terminations. See Table 9 for a list of Approved Vent Materials.
5. Do not install venting system components on the exterior of the building except as specifically required by these instructions.
Vent terminals must be at least 1 foot from any door, window, or gravity inlet into the building.
Maintain the correct clearance and orientation between the exhaust vent and intake pipe terminals.
The exhaust vent and air intake terminals must be at the same height and their center lines must be spaced apart 1 foot
minimum.
The bottom of the exhaust vent and intake pipe terminals must be at least 1 foot above the normal snow accumulation level. In
no case should these terminals be installed less than 1 foot above normal snow accumulation level.
Do not install the exhaust vent terminals directly above windows or doors.
Intake pipe terminal must not terminate in areas that might contain combustion air contaminates, such as near swimming
pools.

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LP-542 REV. 7.16.15
For sidewall venting, the minimum horizontal distance between adjacent exhaust vent terminations is 1 foot. It is
recommended this distance be greater than 1 foot to better avoid frost damage to building surfaces.
For roof venting, minimum horizontal distance between any adjacent exhaust vent termination is 1 foot.
If the exhaust vent is to be terminated in a walled off area (such as a roof with a parapet wall), ensure the exhaust vent
terminates a minimum of 10' from nearest wall and extends level with or above the top of the wall. This will ensure flue gas
does not get trapped and possibly recirculated into the intake air pipe, which could contaminate the combustion air.
Figure 6 –Vent Termination Detail
DESCRIPTION
US
CANADA
A
Clearance above grade, veranda, porch, deck, or balcony
1 foot
1 foot
B
Clearance to window or door that may be opened
1 foot
3 feet
C
Clearance to permanently closed window
*
*
D
Vertical clearance to ventilated soffit located above the
terminal within a horizontal distance of 2 feet from the center
line of the terminal
*
*
E
Clearance to unventilated soffit
*
*
F
Clearance to outside corner
*
*
G
Clearance to inside corner
*
*
H
Clearance to each side of center line extended above meter
/ regulator assembly
*
3 feet with a height 15 feet
above meter / regulator
assembly
I
Clearance to service regulator vent outlet
*
3 feet
J
Clearance to non-mechanical air supply inlet to building or
the combustion air inlet to any other boiler
1 foot
3 feet
K
Clearance to a mechanical air supply inlet
3 feet above if within 10 feet
horizontally
6 feet
L
Clearance above paved sidewalk or driveway located
*
7 feet
M
Clearance under veranda, porch, deck, or balcony
*
1 foot
Table 8 –Vent Termination Clearances
*NOTE: For clearances not specified in ANSI Z223.1/NFPA 54 or CAN/CSA-B 149.1, please use clearances in accordance with local
installation codes and the requirements of the gas supplier.