Mod Con MODCON500 User manual

Mod Con
Volume Water Heaters
Installation
Start-Up
Maintenance
Parts
Warranty
MODCON500 / 700 / 850
VWH Models*
*“VWH” Denotes Hot Water Supply Boiler
“LP” Denotes Propane Gas Operation
“HL” Denotes Installed High and Low Gas Pressure
Switches
“WL” Denotes Installed High Temperature Water Limit
This manual must only be used by a qualied installer / service technician. Read all instructions in this manual before
installing. Perform steps in the given order. Failure to do so could result in substantial property damage, severe
personal injury, or death.
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.
272 Duchaine Blvd. New Bedford, MA 02745 www.htproducts.com
LP-446-r4 Rev. 10.12.16
The surfaces of these products contacted by potable (consumable) water contain less than 0.25% lead by weight as
required by the Safe Drinking Water Act, Section 1417.
Improper installation, adjustment, alteration, service, or maintenance could void product warranty and cause
property damage, severe personal injury, or death.
This Manual For Use With Boilers Manufactured After
August 13, 2013
Heat Exchanger Bears the ASME “H” Stamp

LP-446-r4 Rev. 10.12.16
2
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 THEVICINITY OF THIS OR ANY OTHER APPLIANCE.
WHAT TO DO IFYOU 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 re department. Installation and service must be provided by a qualied
installer, service agency, or the gas supplier.

LP-446-r4 Rev. 10.12.16
3
The following dened 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 serious personal injury or
death.
WARNING indicates a potentially hazardous situation
which, if not avoided, could result in personal injury or death.
CAUTION indicates a potentially hazardous situation which,
if not avoided, may result in moderate or minor personal
injury.
CAUTION used without the safety alert symbol indicates
a potentially hazardous situation which, if not avoided, may
result in property damage.
NOTICE is used to address practices not related to personal
injury.
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 in this system, and additional publications
including the Code for the Installation of Heat Producing
Appliances and National Fuel Gas Code - ANSI Z223.1 (latest
versions), 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
AHJ may be a federal,
state, local government,
or individual such as a
re chief, re marshal,
chief of a re prevention
bureau, labor
department or health
department, building
ocial or electrical
inspector, or others
For the Installer
This boiler must be installed by qualied and licensed personnel.
The installer should be guided by the instructions furnished with
the boiler, and by 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, latest version.
Installations Must Comply With:
Local, state, provincial, and national codes, laws, regulations,
and ordinances.
The latest version of the National Fuel Gas Code, ANSI Z223.1,
from American Gas Association Laboratories, 8501 East Pleasant
Valley Road, Cleveland, OH 44131.
In Canada - CGA No. B149 (latest version), from Canadian Gas
Association Laboratories, 55 Scarsdale Road, Don Mills, Ontario,
Canada M3B 2R3. Also, Canadian Electrical Code, C 22.1, from
Canadian Standards Association, 5060 Spectrum Way, Suite
100, Mississauga, Ontario, Canada L4W 5N6.
Code for the Installation of Heat Producing Appliances (latest
version) from American Insurance Association, 85 John Street,
New York, NY 11038.
The latest version of the National Electrical Code, NFPA No. 70.
NOTE: The gas manifold and controls met safe lighting and
other performance criteria when undergoing tests specied in
ANSI Z21.13 - latest edition.
having statutory authority. In some circumstances, the property
owner or his/her agent assumes the role, and at government
installations, the commanding ocer or departmental ocial
may be the AHJ.
NOTE: HTP, Inc. reserves the right to modify product technical
specications and components without prior notice.

LP-446-r4 Rev. 10.12.16
4
J. Applications 19
Part 5 - Venting and Condensate Removal 22
A. General 22
B. Approved Materials for Exhaust Vent and Intake Pipe 23
C. Additional Requirements for Installation in Canada 23
D. Exhaust Vent and Intake Pipe Location 24
E. Exhaust Vent and Intake Pipe Sizing 25
F. Longer Vent Runs 25
G. Exhaust Vent and Intake Pipe Installation 25
H. Applications 26
1. Direct Vent Installation of Exhaust and Intake 26
2. Room and Indoor Combustion Ventilation Requirements
29
I. Condensate Removal System 30
Part 6 - Wiring 31
A. Installation Must Comply With 31
B. Field Wiring Terminations 31
C. Field Wiring 31
D. Line Voltage Wiring for Standard Boiler 32
E. Alarm Connections 32
F. Low Voltage Connections for Standard Boiler 33
G. Tank Sensor or Mechanical Control 33
H. System / Pipe Sensor 33
I. Optional 0-10 Volt Building Control Signal 33
J. Optional High Gas Pressure Switch 33
K. Optional Low Gas Pressure Switch 33
L. Flow Switch 33
M. Wiring of Cascade System Communication Bus 33
N. Cascade Master Pump and Sensor Wiring 34
O. Cascade Follower Pump and Sensor Wiring 34
Part 7 - Gas Connections 37
A. Gas Piping 37
B. Gas Table 38
C. Check Inlet Gas Pressure 38
D. Boiler Gas Valve 39
Part 8 - Start-Up Preparation 40
A. Check / Control Water Chemistry 40
B. Check for Gas Leaks 40
C. Condensate Removal 40
D. Final Checks Before Starting Boiler 40
E. Setting Up a Single Boiler 40
F. Setting Up a Cascaded System 41
G. Lockout Condition 41
H. Cascade System Programming 41
Part 9 - Start-Up Procedure 42
A. Control Overview 42
B. Navigation of the Display 42
C. Operating Instructions 43
D. Programming Boiler Settings 43
E. Programming the System Setting 44
F. System Setting Program Navigation 44
G. Resetting the Maintenance Schedule 46
Part 10 - Start-Up Procedures for the Installer 46
A. Boiler Control Status Menu 46
B. Cascade Menu 47
C. Boiler Test Mode 48
Part 11 - Troubleshooting 49
A. Boiler Error and Fault Codes 49
B. Boiler Error 49
C. Boiler Fault 49
Table of Contents
Part 1 - General Safety Information 5
A. Improper Combustion 5
B. Gas 5
C. When Servicing the Water Heating System 5
D. Boiler Water 6
E. Freeze Protection 6
F. High Elevation Installations 6
G. Water Temperature Adjustment 6
Part 2 - BeforeYou Start 7
A. What’s in the Box 8
B. How the Boiler Operates 8
C. Optional Equipment 8
Part 3 - Prepare the Boiler 9
A. Locating the Boiler 9
B. Flooring 10
C. Leveling 10
D. Clearances for Service Access 10
E. Residential Garage and Closet Installations 11
F. Exhaust Vent and Intake Pipe 11
1. Direct Vent of Exhaust and Intake 12
2. Indoor Combustion Air in Conned or Unconned Space 12
G. Prevent Combustion Air Contamination 12
H. Removing a Boiler from a Common Vent System 12
I. Water Chemistry Requirements* 13
Part 4 - Piping 14
A. General Plumbing Information 15
B. Relief Valve 15
C. Backow Preventer 15
D. Potable Expansion Tank 15
E. Circulators 16
F. Scalding 16
G. High Velocity Circulator Pump 16
H. Water Chemistry 18
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 o 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
dierence between the inlet and the outlet sensor, which is
aected by boiler water ow. If this temperature dierence
exceeds 55°F (typically because of low water ow or very low
heat load), the control will reduce the maximum fan speed.
If the temperature dierence exceeds 60°F, the control will
eectively sense there is little or no water ow or heat load and
shut the boiler down. The controller will restart automatically
once the temperature dierence has dropped below 55°F and
the minimum o 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.

LP-446-r4 Rev. 10.12.16
5
Part 1 - General Safety Information
This boiler is approved for indoor installations only and is not
intended for use as a pool heater. Clearance to combustible
materials: 0” top, bottom, sides, and back. Left side has
all boiler mechanical connections. Boiler must have room
for service: 24” front is minimum recommended service
clearance. (A combustible door or removable panel is
acceptable front clearance.) This boiler has been approved for
closet installation and installation on combustible ooring. Do
not install directly on carpeting. Install the boiler in a location
where temperature and pressure relief valve discharge or a
leak will not result in damage to the surrounding area. If such
a location is not available, install an auxiliary catch pan. Use
only Category IV vent systems.
Installer - Read all instructions in this manual before installing.
Perform steps in the given order.
User - This manual is for use only by a qualied heating
installer / service technician. Have this boiler serviced /
inspected annually by a qualied service technician.
FAILURE TO ADHERE TO THE GUIDELINES ON THIS PAGE
CAN RESULT IN SUBSTANTIAL PROPERTY DAMAGE,
SEVERE PERSONAL INJURY, OR DEATH.
NOTE: If the boiler is exposed to the following, do not
operate. Immediately call a qualied service technician.
1. Fire
2. Damage
3. Water
Failure to follow this information could result in property
damage, severe personal injury, or death.
DO NOT USE THIS BOILER IF ANY PART HAS BEEN
SUBMERGED IN WATER. Immediately call a qualied
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 re 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 ood or submersion is
considered an Act of God, and IS NOT covered under product
warranty.
NOTE: Obey all local codes. Obtain all applicable permits
before installing the boiler.
NOTE: Install all system components and piping in such a
manner that does not reduce the performance of any re
rated assembly.
Altering any HTP, Inc. boiler with parts not manufactured by
HTP, Inc. WILL INSTANTLY VOID the boiler warranty and could
result in property damage, personal injury, or death.
This boiler has been designed to heat potable water ONLY.
Using this boiler to heat non-potable uid WILL VOID product
warranty, and could result in property damage, personal injury,
or death.
Do not use this boiler for anything other than its intended
purpose (as described in this manual). Doing so could result in
property damage and WILL VOID product warranty.
High heat sources (sources generating heat 100oF / 37oC or
greater, such as stove pipes, space heaters, etc.) may damage
plastic components of the boiler as well as plastic vent pipe
materials. Such damages ARE NOT covered by warranty. It is
recommended to keep a minimum clearance of 8” from high
heat sources. Observe heat source manufacturer instructions,
as well as local, state, provincial, and national codes, laws,
regulations and ordinances when installing this boiler and
related components near high heat sources.
A. Improper Combustion
Do not obstruct the ow of combustion and ventilating air.
Adequate air is necessary for safe operation. Failure to keep the
exhaust vent and combustion air intake clear of ice, snow, or
other debris could result in property damage, serious personal
injury, or death.
B. Gas
Should overheating or gas supply fail to shut o, turn o the
manual gas control valve to the boiler.
C. When Servicing the Water Heating System
To avoid electric shock, disconnect electrical supply before
performing maintenance.
NOTE: When inquiring about service or troubleshooting,
reference the model and serial numbers from the boiler rating
label.
To avoid severe burns, allow boiler and associated equipment to
cool before servicing.
Be sure to disconnect electrical power before opening boiler
cabinet or performing service. Failure to do so could result in
electrical shock, property damage, serious personal injury, or
death.
D. User Interface Display 50
Part 12 - Maintenance 55
A. Procedures 55
B. Combustion Chamber Coil Cleaning Instructions 55
C. Cleaning Water Side of Heat Exchanger 56
Part 13 - Installation Checklist 61
Part 14 - Maintenance Report 61
Limited Warranty 65
Maintenance Notes 67
Customer Installation Record Form 68
Due to low water content of the boiler, improperly sizing the
boiler in regard to potable water heating load will result in
excessive boiler 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.

LP-446-r4 Rev. 10.12.16
6
NEVER use any toxic chemical, including automotive, standard
glycol antifreeze, or ethylene glycol made for hydronic (non-
potable) systems. These chemicals can attack gaskets and seals
in water systems, are poisonous if consumed, and can cause
personal injury or death.
UNCRATING THE BOILER - Any claims for damage or
shortage in shipment must be led immediately against the
transportation company by the consignee.
Households with small children, disabled, or elderly persons
may require a 120oF or lower temperature setting to prevent
severe personal injury or death due to scalding.
G. Water Temperature Adjustment
If the boiler is going to have a set temperature above 120oF, you
must use an ASSE 1017 rated mixing valve to avoid severe burns
or death from scalding temperatures.
Approximate Time / Temperature Relationships in Scalds
120oF More than 5 minutes
125oF 1 1/2 to 2 minutes
130oF About 30 seconds
135oF About 10 seconds
140oF Less than 5 seconds
145oF Less than 3 seconds
150oF About 1 1/2 seconds
155oF About 1 second
Table 1 - Approximate Time / Temperature Relationships in Scalds
Failure of the boiler due to freeze related damage IS NOT
covered by product warranty.
E. Freeze Protection
NOTE: Consider piping and installation when determining boiler
location.
D. Boiler Water
Do not use petroleum-based cleaning or sealing compounds in
a water heating system. Gaskets and seals in the system may be
damaged. This can result in substantial property damage.
Do not use “homemade cures” or “patent medicines”. Damage
to the boiler, substantial property damage, and/or serious
personal injury may result.
F. High Elevation Installations
Natural gas at high elevation might contain less heating value
than typical 1,000 BTU/cu ft and therefore can cause improper
air / gas mix leading to improper combustion. For natural gas
installations above 3,000 ft, call your gas provider to determine
the heating value of the supplied natural gas.

LP-446-r4 Rev. 10.12.16
7
Part 2 - Before You Start
CAUTION
VWH units must be connected to a storage tank. You must not have a direct connection of the potable water system into the heat
exchanger. This could cause ow issues, short cycling, and an increase of mineral build-up in the unit. This system is designed
to have incoming potable water ow through the storage tank rst, then through the heat exchanger. Failure to connect the
VWH boiler to a storage tank of the minimum size requirements (119 gallons for a single 500VWH; 175 gallons for a single
700/850VWH) will result in property damage and/or premature boiler failure. Damages resulting from incorrect installation or
from use of products not approved by HTP, Inc. ARE NOT covered by warranty.
∆T
(Delta T)
(oF)
500VWH 700VWH 850VWH
Gallons
Per Hour
First
Hour
Rating
119
Gallon
Tank
First
Hour
Rating
175
Gallon
Tank
First
Hour
Rating
200
Gallon
Tank
Gallons
Per Hour
First
Hour
Rating
119
Gallon
Tank
First
Hour
Rating
175
Gallon
Tank
First
Hour
Rating
200
Gallon
Tank
Gallons
Per Hour
First
Hour
Rating
175
Gallon
Tank
First
Hour
Rating
200
Gallon
Tank
First
Hour
Rating
300
Gallon
Tank
Contact HTP for Available
Storage Tanks
Contact HTP for Available
Storage Tanks
Contact HTP for Available
Storage Tanks
40o1414 859 883 894 1980 1206 1217 1260 2404 1449 1459 1502
50o1131 872 902 915 1584 1225 1238 1292 1923 1467 1481 1534
60o943 884 920 937 1320 1244 1260 1324 1602 1486 1502 1566
70o808 897 939 958 1131 1262 1281 1356 1374 1505 1524 1599
80o707 910 958 979 990 1281 1303 1388 1202 1524 1545 1631
90o628 923 977 1001 880 1300 1324 1420 1068 1542 1566 1663
100o566 935 995 1022 792 1319 1345 1453 961 1561 1588 1695
110o514 948 1014 1044 720 1337 1367 1485 874 1580 1609 1727
120o471 961 1033 1065 660 1356 1388 1517 801 1599 1631 1759
130o435 974 1052 1087 609 1375 1410 1549 740 1617 1652 1791
140o404 986 1070 1108 566 1394 1431 1581 687 1636 1674 1824
Table 2 - VWH Ratings with Storage Tanks - NOTE: Gallons Per Hour Does Not Take a Storage Tank into Account
Min Tank Size (Gal.) = Required Flow (GPM) X 10
Mixing Factor (Mf) = VWH Outlet Temp - Inlet Temp
70
First Hour Rating = Total VWH Output X VWH Eciency + .75 X Total Storage X Mf
[ (VWH Outlet Temp - Inlet Temp) X 8.31 ]
Example:
2 500VWH Boilers - Total Output = 1,000,000 BTU @ 94% Eciency
VWH Outlet Temp = 140oF - Inlet Temp = 40oF
2 Storage Tanks (119 Gallons Each) =Total Storage = 238 Gallons
Mixing Factor (Mf) = 140 - 40 = 1.43
70
First Hour Rating = 1,000,000 X .94 + .75 X 238 X 1.43
[ (140 - 40) X 8.31 ]
First Hour Rating = 940,000 + 179 X 1.43
[ 831 ]
First Hour Rating = [1,131 + 179] X 1.43
First Hour Rating = 1,310 X 1.43
First Hour Rating = 1,873 Gallons

LP-446-r4 Rev. 10.12.16
8
C. Optional Equipment
Optional equipment available from HTP (and Part #):
• Indirect Tank Sensor (7250P-325)
• 4” Stainless Steel Vent Termination Kit (V2000)
• 6” Stainless Steel Vent Termination Kit (V3000)
• High and Low Gas Pressure Switch Kit with Manual
Reset (7350P-600)
• UL 353 Compliant Low Water Cut-O Interface Kit with
Manual Reset (7350P-601)
• Alarm System (to monitor any failure) (7350P-602)
• PC Connection Kit (7250P-320)
• Condensate Neutralizer (7350P-611)
• Caster Kit (7350p-604)
• Glass-Lined Storage Tanks (GL-119, GL-175)
• Stainless Steel Storage Tank (SSU-119CB)
Remove all sides of the shipping crate of the boiler.
Components included with the boiler:
• Temperature and Pressure Gauge
• Pressure Relief Valve
• Three (3) Stainless Steel Screens
• Supply and Return Thermistors
• Wiring Harness
• Flow Switch and Fitting
• System/Pipe Sensor
• Installation Manual and Warranty
• User’s Information Manual
• CSD-1 Form
• H-3 Data Sheet
A. What’s in the Box
B. How the Boiler Operates
VWH® condensing technology intelligently delivers large
amounts of hot water while maximizing eciency. Outlined
below are the features of the system and how they operate:
Stainless Steel Heat Exchanger
The highly ecient stainless steel heat exchanger is designed to
use the cold water return from the storage tank and extract the
last bit of heat before it is exhausted.
Modulating Combustion System
The combustion system modulates the output of the burner
during operation to match system demand and achieve the
control set point while in operation. The set point can change by
internal or external signals to enhance the overall performance
of the system.
Control
The integrated control system monitors the system and
regulates fan speed to control boiler output. This allows the
boiler to deliver only the amount of heat energy required and
nothing more.
The control can 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 eciency.
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 ow and control heat exchanger ow 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 ow only if
powered and combustion air is owing.
Integrated Venturi (500 Models) or Swirl Plate (700/850
Models)
Controls air and gas ow into the burner.
Burner
The high grade stainless steel burner uses premixed air and gas
to provide a wide range of ring rates.
Spark Ignition
The burner is ignited by applying high voltage through the
system spark electrode. The spark from the electrode ignites
mixed gas o of the burner.
Supply Water Temperature Sensor
This sensor monitors the boiler outlet water temperature
(System Supply). The control adjusts boiler ring rate so the
supply temperature will match the boiler set point.
Return Water Temperature Sensor
This sensor monitors boiler return water temperature (System
Return).
Temperature and Pressure Gauge
Allows the user to monitor system temperature and pressure.
Electrical eld connections with terminal strips
The electrical cover allows easy access to the clearly marked
line voltage and low voltage terminal strips to facilitate wiring
the boiler.
Condensate Collection System
This boiler is a high eciency appliance and will produce
condensate. The condensate collection system has a oat
switch which monitors condensate level and prevents
condensate from backing up into the combustion system.
Inside the collection system 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.
Flow Protection
The supplied ow switch is designed to protect the boiler
during low ow conditions. The boiler control also monitors
ow through the heat exchanger by monitoring the return
and supply sensors and will shut down the burner before
overheating occurs.
System Pipe Sensor
This sensor is designed to be used in a cascade system. When
placed on the supply line feeding the storage tank, the system
pipe sensor measures the temperature of return water and
communicates with the control system to modulate the ring
rate of the connected boilers.
NOTE: When using a system sensor, pipe insulation must be
wrapped around it to improve temperature measurement
accuracy and increase overall system eciency.
0-10 Volt Input
Allows the installer to connect a BMS (Building Management
System) to control the boiler.
Indirect Tank Sensor (optional)
Monitors storage tank temperature.

LP-446-r4 Rev. 10.12.16
9
Part 3 - Prepare the Boiler
COLDWEATHER HANDLING - If the boiler has been stored in
a very cold location (BELOW 0oF) before installation, handle
with care until the components come to room temperature.
Failure to do so could result in damage to the boiler.
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.
Remove all sides of the shipping crate to allow the boiler to
be moved into its installation location. Pick the boiler up by
the lifting rings to avoid damage to the boiler enclosure. Use
either solid 3/4” diameter black iron pipe or lifting straps to lift
the boiler o its shipping crate. The boiler is heavy. At least
two individuals are needed to properly handle the boiler. The
boiler is also equipped with leveling feet that can be used
to level the boiler properly on an uneven location surface. If
surface ooring is rough, take care when moving the boiler
into position, as catching the leveling feet could damage the
boiler.
Figure 1 - Lifting the Boiler
This boiler is certied for indoor use only. DO NOT INSTALL
OUTDOORS. Outdoor installations ARE NOT covered by
warranty. Failure to install the boiler indoors could result in
property damage, severe personal injury, or death.
A. Locating the Boiler
Incorrect ambient conditions can lead to damage to the
heating system and put safe operation at risk. Ensure that
the 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
• Ensure a minimum 1” clearance around hot water and
exhaust vent pipes
• NOTE: To prevent condensing in the fan, it is recommended
to avoid prolonged exposure to temperatures below 45oF
This boiler has a condensate disposal system that may freeze
if exposed to sustained temperatures below 32oF. Precautions
should be taken to protect the condensate trap and drain lines
from sustained freezing conditions. Failure to take precautions
could result in 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 ammable liquids.
Failure to keep the boiler area clear and free of combustible
materials, liquids, and vapors can result in substantial property
damage, severe personal injury, or death.

LP-446-r4 Rev. 10.12.16
10
High heat sources (generating heat 100oF / 37oC or greater,
such as boiler ue pipes, space heaters, etc.) may damage
plastic components of the boiler as well as plastic vent pipe
materials. Such damages ARE NOT covered by warranty. It is
recommended to keep a minimum clearance of 8” from high
heat sources. Observe heat source manufacturer instructions,
as well as local, state, provincial, and national codes, laws,
regulations, and ordinances when installing this boiler and
related components near high heat sources.
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 ush 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.
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 oors of the building. The boiler
should be located near a oor drain or installed in a drain pan.
Leakage damages ARE NOT covered by warranty.
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 inuenced 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 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.
Failure of the boiler or components due to incorrect operating
conditions IS NOT covered by product warranty.
Use extreme care not to drop the boiler or cause bodily injury
while lifting the boiler.
Gas conversion should be performed BEFORE the boiler is
installed. Carefully follow the gas conversion instructions when
performing the conversion.
Failure to follow these instructions could result in property
damage, severe personal injury, or death.
C. Leveling
In order for the condensate to properly ow out of the
collection system, the area where you locate the boiler must
be level. Location must also fully support the weight of the
lled boiler.
Figure 2 - Correct and Incorrect Leveling
D. Clearances for Service Access
NOTE: If you do not provide the minimum clearances shown
in Figure 3 it might not be possible to service the boiler without
removing it from the space.
NOTE: A combustible door or removable panel is acceptable
front clearance.
The 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 the boiler 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
warnings could result in substantial property damage, severe
personal injury, or death.
Assure that the oor and structure of the installation location
are sucient to support the full installed weight of the
boiler, including water content of the heat exchanger and
related piping. Failure to ensure the oor and structure of the
installation location are structurally sound before installation
of the boiler can result in structural failure, substantial
property damage, severe personal injury, or death.
This boiler is approved for installation on combustible ooring,
but must never be installed on carpeting. Installing this boiler on
carpeting could result in re, property damage, severe personal
injury, or death.
B. Flooring
This boiler must be installed upright in the vertical position
as described in this manual. DO NOT attempt to install this
boiler in any other orientation. Doing so will result in improper
boiler operation and property damage, and could result in
serious personal injury or death.