U.S. Boiler Company Alpine ALP080B Service manual

103448-10 - 6/18 Price - $5.00
9700609
Installation, Operating and Service Instructions for
Condensing
High Efficiency
Direct Vent
Gas-Fired
Water Boiler
ALPINETM
Residential
As an ENERGY STAR®Partner, U.S. Boiler
Company has determined that the ALPINE™
Series meets the ENERGY STAR®guidelines for
energy efficiency established by the United States
Environmental Protection Agency (EPA).
TO THE INSTALLER:
Affix these instructions adjacent to boiler.
TO THE CONSUMER:
Retain these instructions for future reference.
Models: 08 MBH through 285 MBH
Improper installation, adjustment, alteration, service or maintenance can cause property
damage, injury, or loss of life. For assistance or additional information, consult a qualified installer,
service agency or the gas supplier. This boiler requires a special venting system. Read these instructions
carefully before installing.
WARNING

2 103448-10- 6/18
IMPORTANT INFORMATION - READ CAREFULLY
NOTE: The equipment shall be installed in accordance with those installation regulations enforced in the area where
the installation is to be made. These regulations shall be carefully followed in all cases. Authorities having
jurisdiction shall be consulted before installations are made.
All wiring on boilers installed in the USA shall be made in accordance with the National Electrical Code and/or
local regulations.
All wiring on boilers installed in Canada shall be made in accordance with the Canadian Electrical Code and/or
local regulations.
The City of New York requires a Licensed Master Plumber supervise the installation of this product.
The Massachusetts Board of Plumbers and Gas Fitters has approved the Alpine™ Series boiler. See the
Massachusetts Board of Plumbers and Gas Fitters website, http://license.reg.state.ma.us/pubLic/pl_products/pb_
pre_form.asp for the latest Approval Code or ask your local Sales Representative.
The Commonwealth of Massachusetts requires this product to be installed by a Licensed Plumber or Gas Fitter.
The following terms are used throughout this manual to bring attention to the presence of hazards of various
risk levels, or to important information concerning product life.
Indicates an imminently
hazardous situation which, if not avoided, will
result in death, serious injury or substantial
property damage.
DANGER Indicates a potentially
hazardous situation which, if not avoided, may
result in moderate or minor injury or property
damage.
CAUTION
Indicates a potentially
hazardous situation which, if not avoided,
could result in death, serious injury or
substantial property damage.
WARNING NOTICE Indicates special instructions on
installation, operation, or maintenance which
are important but not related to personal injury
hazards.
Explosion Hazard. DO NOT store or use gasoline or other flammable vapors or liquids
in the vicinity of this or any other appliance.
If you smell gas vapors, DO NOT try to operate any appliance - DO NOT touch any electrical switch or use
any phone in the building. Immediately, call the gas supplier from a remotely located phone. Follow the
gas supplier’s instructions or if the supplier is unavailable, contact the fire department.
DANGER

103448-10 - 6/18 3
A. For all sidewall horizontally vented gas fueled equipment installed in every dwelling, building or structure used in whole
or in part for residential purposes and where the sidewall exhaust vent termination is less than seven (7) ft. above
grade, the following requirements shall be satisfied:
1. If there is no carbon monoxide detector with an alarm already installed in compliance with the most current
edition of NFPA 720, NFPA 70 and the Massachusetts State Building Code in the residential unit
served by the sidewall horizontally vented gas fueled equipment, a battery operated carbon monoxide
detector with an alarm shall be installed in compliance with the most current edition of NFPA 720, NFPA 70
and the Massachusetts State Building Code.
2. In addition to the above requirements, if there is not one already present, a carbon monoxide detector with
an alarm and a battery back-up shall be installed and located in accordance with the
installation requirements supplied with the detector on the floor level where the gas equipment is installed.
The carbon monoxide detector with an alarm shall comply with 527 CMR, ANSI/UL 2034 Standards or CSA
6.19 and the most current edition of NFPA 720. In the event that the requirements of this subdivision can not
be met at the time of the completion of the installation of the equipment, the installer shall have a period
of thirty (30) days to comply with this requirement; provided, however, that during said thirty (30) day period,
a battery operated carbon monoxide detector with an alarm shall be installed in compliance with the most
current edition of NFPA 720, NFPA 70 and the Massachusetts State Building Code. In the event that
the sidewall horizontally vented gas fueled equipment is installed in a crawl space or an attic, the
carbon monoxide detector may be installed on the next adjacent habitable floor level. Such detector may
be a battery operated carbon monoxide detector with an alarm and shall be installed in compliance with the
most current edition of NFPA 720, NFPA 70 and the Massachusetts State Building Code.
3. A metal or plastic identification plate shall be permanently mounted to the exterior of the building at a
minimum height of eight (8) ft. above grade directly in line with the exhaust vent terminal for the horizontally
vented gas fueled heating appliance or equipment. The sign shall read, in print size no less than one-half
(1/2) inch in size, “GAS VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS”.
4. A final inspection by the state or local gas inspector of the sidewall horizontally vented equipment shall not
be performed until proof is provided that the state or local electrical inspector having jurisdiction has granted
a permit for installation of carbon monoxide detectors and alarms as required above.
B. EXEMPTIONS: The following equipment is exempt from 248 CMR 5.08(2)(a) 1 through 4:
1. The equipment listed in Chapter 10 entitled “Equipment Not Required To Be Vented” in the most current
edition of NFPA 54 as adopted by the Board; and
2. Product Approved sidewall horizontally vented gas fueled equipment installed in a room or structure
separate from the dwelling, building or structure used in whole or in part for residential purposes.
C. When the manufacturer of Product Approved sidewall horizontally vented gas equipment provides a venting
system design or venting system components with the equipment, the instructions for installation of the
equipment and the venting system shall include:
1. A complete parts list for the venting system design or venting system; and
2. Detailed instructions for the installation of the venting system design or the venting system components.
D. When the manufacturer of a Product Approved sidewall horizontally vented gas fueled equipment does not
provide the parts for venting flue gases, but identifies “special venting systems”, the following shall be satisfied:
1. The referenced “special venting system” instructions shall be included with the appliance or equipment
installation instructions; and
2. The “special venting systems” shall be Product Approved by the Board, and the instructions for that system
shall include a parts list and detailed installation instructions.
E. A copy of all installation instructions for all Product Approved sidewall horizontally vented gas fueled equipment,
all venting instructions, all parts lists for venting instructions, and/or all venting design instructions shall remain
with the appliance or equipment at the completion of the installation.
Special Installation Requirements for Massachusetts

4 103448-10- 6/18
I. Product Description, Specifications and Dimensional Data...................... 5
II. Unpacking Boiler........................................................................................ 9
III. Pre-Installation and Boiler Mounting ........................................................ 10
I V. Venting...................................................................................................... 17
A. General Guidelines............................................................................... 18
B. CPVC/PVC Venting.............................................................................. 22
C. Polypropylene Venting......................................................................... 35
D. Stainless Steel Venting........................................................................ 43
E. Removing the Existing Boiler............................................................... 48
F. Multiple Boiler Installation Venting....................................................... 50
V. Condensate Disposal................................................................................. 52
VI. Water Piping and Trim............................................................................... 54
VII. Gas Piping ............................................................................................... 70
VIII. Electrical ................................................................................................... 74
IX. System Start-up ....................................................................................... 88
X. Operation...................................................................................................... 96
A. Overview............................................................................................... 96
B. Supply Water Temperature Regulation................................................ 97
C. Boiler Protection Features.................................................................... 98
D. Multiple Boiler Control Sequencer........................................................ 99
E. Boiler Sequence of Operation.............................................................. 100
1. Normal Operation........................................................................... 100
2. Using The Display.......................................................................... 101
3. Status Screens.............................................................................. 102
4. Detail Screens............................................................................... 104
5. Multiple Boiler Sequencer Screens................................................ 105
F. Changing Adjustable Parameters........................................................ 106
1. Entering Adjust Mode.................................................................... 106
2. Adjusting Parameters..................................................................... 107
XI. Service and Maintenance ........................................................................ 124
XII. Troubleshooting........................................................................................ 131
XIII. Repair Parts ............................................................................................. 136
Table of Contents

103448-10 - 6/18 5
I. Product Description, Specifications and Dimensional Data
Alpine™ Series boilers are condensing high
efficiency gas-fired direct vent hot water heating
boilers designed for use in forced hot water space
or space heating with indirect domestic hot water
heating systems, where supply water temperature
does not exceed 210°F. These boilers have special
coil type stainless steel heat exchangers, constructed,
tested and stamped per Section IV ‘Rules for
Construction of Heating Boilers’ of ASME Boiler and
Pressure Vessel Code, which provide a maximum
heat transfer and simultaneous protection against
flue gas product corrosion. These boilers are not
designed for use in gravity hot water space heating
systems or systems containing significant amount
of dissolved oxygen (swimming pool water heating,
direct domestic hot water heating, etc.).
Dimension Boiler Model
ALP080B (1) ALP105B (1) ALP150B (1) ALP210B (1) ALP285B (2)
A - Inch
(mm)
12-9/16
(320)
14
(356)
19-11/16
(500)
23-15/16
(608)
21-13/16
(554)
B - Inch
(mm)
5-5/8
(142)
5-13/16
(147)
7-5/16
(185)
C - Inch
(mm)
7-5/16
(186)
14-1/8
(358)
D - Inch
(mm)
9-5/16
(237)
10-3/4
(273)
16-7/16
(417)
17-1/8
(435)
18
(456)
E - Inch
(mm)
5-15/16
(151)
12-1/4
(312)
Gas Inlet F
(FPT) 1/2” 3/4”
Return G
(FPT) 1” 1-1/4”
Supply H
(FPT) 1” 1-1/4”
Condensate Drain J * * Factory Provided Socket End Compression Pipe Joining Clamp
for 3/4” Schedule 40 PVC Pipe
Boiler Two-Pipe
CPVC/PVC Vent Connector
(Figs. 1A, 1C) - Inch
3 x 3 4 x 4
Boiler
CPVC Vent Connector/Pipe
(Fig. 1B) - Inch
3” N/A
Boiler Inlet Air Connector
(Fig. 1B) - Inch 3” N/A
Table 1B: Dimensional Data (See Figures 1A, 1B, 1C)
NOTES:
(1) - These boiler models available as either Floor mounted (suffix F) or, Wall mounted (suffix W).
(2) - This boiler model available as Floor mounted (suffix F) only.
Specification Boiler Model
ALP080B ALP105B ALP150B ALP210B ALP285B
Altitude (ft. above sea level) 0-4500 0-4500 0-4500 0-4500 0-4500
Fuel Shipped for Natural Gas, Field Converted for LP Gas
Max. Allowable Water Temperature (°F) 210
Max. Allowable Working Pressure (psi) 160
Factory supplied Safety Relief Valve (psi) * 30
Boiler Water Volume (gal.) 0.6 0.7 1. 3 1. 7 2.4
Heat Transfer area (sq. ft.) 7. 3 9.1 16.4 21.8 29.1
Approx. Shipping weight (lb.) 137 155 182 206 256
Table 1A: Specifications
* Optional 50 psi, 80 psi and 100 psi safety relief valves are available for all models.

6 103448-10- 6/18
Figure 1A: Models ALP080B through ALP210B (Floor Mounted)
I. Product Description, Specifications and Dimensional Data (continued)

103448-10 - 6/18 7
I. Product Description, Specifications and Dimensional Data (continued)
Figure 1B: Models ALP080B through ALP210B (Wall or Floor Mounted)
I. Product Description, Specifications and Dimensional Data (continued)

8 103448-10- 6/18
Figure 1C: Model ALP285B (Floor Mounted)
I. Product Description, Specifications and Dimensional Data (continued)

103448-10 - 6/18 9
I. Product Description, Specifications and Dimensional Data (continued)
Table 2: Ratings
I. Product Description, Specifications and Dimensional Data (continued)
Alpine Series Gas-Fired Boilers
Model Number Input (MBH) Heating Capacity
(MBH)
Net AHRI Ratings Water 1
(MBH)
AFUE
(%)
Min. Max.
ALP080B 16 80 72 63 95.0
ALP105B 21 105 96 83 95.0
ALP150B 30 150 136 118 95.0
ALP210B 42 210 194 169 95.0
ALP285B 57 285 262 228 95.0
Ratings shown are for installations at sea level and elevations up to 2000 ft. For elevations above 2000 ft., the boiler will
naturally derate by 2.5% for each 1000 ft. above sea level - applicable to ALP080B thru ALP210B.
ALP285B rating is for installation at sea level and elevations up to 7800 ft. For elevations above 7800 ft., the boiler will
naturally derate by 1.8% for each 1000 ft. above sea level.
1Net AHRI Water Ratings based on piping and pickup allowance of 1.15. Consult manufacturer before selecting boiler
for installations having unusual piping and pickup requirements, such as intermittent system operation, extensive piping
systems, etc.
II. Unpacking Boiler
A. Move boiler to approximate installed position.
B. Remove all crate fasteners.
C. Lift and remove outside container.
D. Remove boiler from cardboard positioning sleeve
on shipping skid.
E. Move boiler to its permanent location.
Do not drop boiler.
CAUTION
Installation of this boiler
should be undertaken only by trained and
skilled personnel from a qualified service
agency.
WARNING

10 103448-10- 6/18
A. Installation must conform to the requirements
of the authority having jurisdiction in or, in the
absence of such requirements, to the National
Fuel Gas Code, ANSI Z223.1/NFPA 54, and/or
Natural Gas and Propane Installation Code,CAN/
CSA B149.1.
Where required by the authority having
jurisdiction, the installation must conform to the
Standard for Controls and Safety Devices for
Automatically Fired Boilers, ANSI/ASME CSD1.
B. Boiler is certified for installation on combustible
flooring. Do not install boiler on carpeting.
C. Provide clearance between boiler jacket and
combustible material in accordance with local fire
ordinance. Refer to Figure 2A or 2B for minimum
listed clearances from combustible material.
Recommended service clearance is 24 in. (610
mm) from left side, front, top and rear of the boiler.
Recommended front clearance may be reduced
to the combustible material clearance providing:
1. Access to boiler front is provided through a
door or removable front access panel.
III. Pre-Installation and Boiler Mounting
2. Access is provided to the condensate trap
located underneath the heat exchanger.
3. Access is provided to thermal link
located at boiler rear.
D. Protect gas ignition system components from
water (dripping, spraying, rain, etc.) during boiler
operation and service (circulator replacement,
condensate trap, control replacement, etc.).
E. Provide combustion and ventilation air in
accordance with section “Air for Combustion
and Ventilation,” of National Fuel Gas Code, ANSI
Z223.1/NFPA 54, or Clause 8.2, 8.3, or 8.4 of
Natural Gas and Propane Installation Code, CAN/
CSA B149.1, or applicable provisions of local
building Codes.
F. The boiler should be located so as to minimize
the length of the vent system. The combustion
air piping must terminate where outdoor air is
available for combustion and away from areas that
may contaminate combustion air. In particular,
avoid areas near chemical products containing
chlorines, chlorofluorocarbons, paint removers,
cleaning solvents and detergents. Avoid areas
containing saw dust, loose insulation fibers, dry
wall dust etc.
G. General
1. Alpine boilers are intended for installations
in an area with a floor drain or in a suitable
drain pan to prevent any leaks or relief valve
discharge to cause property damage.
2. Alpine boilers are not intended to support
external piping and venting. All external piping
and venting must be supported independently
of the boiler.
3. Alpine boilers must be installed level to
prevent condensate from backing up inside the
boiler.
4. Alpine boilers can be installed either as
floor standing (ALP080B through ALP285B)
or as wall hung (ALP080B through ALP210B).
WARNING
WARNING
NOTICE Due to the low water content of the
boiler, mis-sizing of the boiler with regard to
the heating system load will result in excessive
boiler cycling and accelerated component
failure. U.S. Boiler Company DOES NOT
warrant failures caused by mis-sized boiler
applications. DO NOT oversize the boiler to
the system. Multiple boiler installations greatly
reduce the likelihood of boiler oversizing.
Explosion Hazard.
Asphyxiation Hazard. Electrical Shock Hazard.
Installation of this boiler should be undertaken
only by trained and skilled personnel from
a qualified service agency. Follow these
instructions exactly.
Improper installation, adjustment, service,
or maintenance can cause property damage,
personal injury or loss of life.
Asphyxiation Hazard. Models
with Two-Pipe Vent Connector:
Apply supplied dielectric grease to gasket
inside vent section of two-pipe vent connector.
Failure to apply the grease could result in flue
gas leaks from gasket rupture during vent
pipe installation or gasket deterioration due to
condensate exposure.
Indicates a potentially
hazardous situation which, if not avoided,
could result in death, serious injury or
substantial property damage.
WARNING
NOTICE Avoid operating this boiler in an
environment where sawdust, loose insulation
fibers, dry wall dust, etc. are present. If boiler
is operated under these conditions, the
burner interior and ports must be cleaned and
inspected daily to insure proper operation.

103448-10 - 6/18 11
Factory assembled floor standing models are
identified with suffix F in a boiler part number
code (example _ ALP210BF-4G02). Factory
assembled wall hung models are identified
with suffix W in a boiler part number code
(example - ALP210BW-4G02).
5. Boiler Floor Standing Installation:
a. For basement installation provide a solid
base such as concrete, where floor is not
level or water may be encountered on the
floor around boiler.
Floor must be able to support weight of
boiler, water and all additional system
components.
b. Boiler must be level to prevent condensate
from backing up inside the boiler.
c. Provide adequate space for condensate
piping or a condensate pump if required.
Boiler Clearances to Combustible (and Non-
Combustible) Material:
Models ALP080B through ALP210B and
ALP285B:
These boilers are listed for closet installation with
the following minimum clearances – Top = 1 in.
(25 mm), Front = 1 in. (25 mm), Left Side = 10 in.
(250 mm), Right Side = 2 in. (50 mm), Rear = *6
in. (150 mm)
* Note:
When boiler is vented vertically, the minimum
clearance from the rear of the jacket is
increased to 18 in. (460 mm) with a short
radius 90° elbow in order to provide adequate
space at boiler rear for installation of vent and
air intake piping and service access.
Boiler Service Clearances – Applicable to all Boiler
Models:
Top = 24 in. (610 mm), Front = 24 in. (610 mm),
Left Side = 24 in. (610 mm), Right Side = 24 in.
(610 mm), Rear = 24 in. (610 mm)
The above clearances are recommended for
service access but may be reduced to the
Combustible Material Clearances provided:
III. Pre-Installation and Boiler Mounting G. General (continued)
Listed Direct
Vent System
Vent Pipe
Material
Vent
Pipe
Direction
Enclosure
Vent Pipe
Nominal
Diameter
Minimum
Clearance to
Combustible
Material
Factory Standard
Two-Pipe CPVC/PVC Vent and PVC
Combustion Air Intake
* CPVC/PVC
Vertical or
Horizontal
Unenclosed
at all Sides
3 in. (80 mm)
or
4 in. (100 mm)
1 in. (25 mm)
Available Optional
Two-Pipe Rigid Polypropylene Vent
(or, Flexible Polypropylene Liner
for Vertical Venting only) and Rigid
Polypropylene or PVC Combustion
Air Intake
Pipe Rigid
Polypropylene
Vent (or,
Flexible
Polypropylene
Liner for
Vertical
Venting only)
3 in. (80 mm)
or (110 mm)
or
4 in. (100 mm)
or (110 mm)
1 in. (25 mm)
Available Optional
Two-Pipe Stainless Steel Vent and
Galvanized Steel or PVC Combustion
Air Intake
Stainless
Steel
3 in. (80 mm)
or
4 in. (100 mm)
1 in. (25 mm)
Figure 2A: Clearances To Combustible and Non-combustible Material, Floor Standing

12 103448-10- 6/18
Figure 2B: Clearances To Combustible and Non-combustible Material, Wall Mounted
III. Pre-Installation and Boiler Mounting G. General (continued)
a. The boiler front is accessible through a
door.
b. Access is provided to the condensate trap
located on the left side of boiler.
c. Access is provided to thermal link located
at the boiler rear (ALP285B only).
6. Boiler Wall Hung Installation:
a. If the boiler is installed on a framed wall,
minimum acceptable framing is 2 x 4 studs
on 16” centers. The boiler mounting holes
are on 16” centers for installation between
two studs at the standard spacing. In
cases where the boiler cannot be centered
between the studs, or where the studs
are spaced closer than 16” apart, the
boiler may be anchored to ¾” plywood or
horizontal 2 x 4’s anchored to the studs.
b. Locate Wall Mounting Bracket Kit carton
(P/N 102988-01) enclosed inside boiler
carton. The kit contains Wall Mounting
Bracket, Bottom Securing Bracket, (4) 5/16”
x 2” long hex head lag screws, (4) 5/16”
flat plated washers and (2) #8 x ½” Phillips
round head sheet metal screws.
c. 5/16 in. x 2 in. lag screws and 5/16 in.
plated washers are intended for mounting
the boiler directly onto studs covered
with ½ in. drywall. When the boiler is
attached to other types of construction,
such as masonry, use fasteners capable
of supporting the weight of the boiler and
attached piping in accordance with good
construction practice and applicable local
codes.
Alpine boiler approximate dry
weights:
ALP080BW – 98 lbs; ALP105BW – 112 lbs;
ALP150BW – 136 lbs: ALP210BW – 150 lbs
Two people are required to safely lift these
boilers onto the installed wall mounting
bracket.
Make sure that wall mounting bracket is
anchored to a structure capable of supporting
the weight of the boiler and attached piping
when filled with water. Jurisdictions in areas
subject to earthquakes may have special
requirements for supporting these boilers.
Such local requirements take precedence over
the requirements shown below.
CAUTION

103448-10 - 6/18 13
III. Pre-Installation and Boiler Mounting G. General (continued)
d. Make sure that the surface to which the
boiler is mounted is plumb.
e. Before mounting the boiler, make sure that
wall selected does not have any framing or
other construction that will interfere with the
vent pipe penetration.
f. Once a suitable location has been selected
for the boiler, and any needed modifications
have been made to the wall, use Figure
2C to locate and layout holes “A” and
“B”. These holes must be positioned
on mounting stud centers if the boiler is
installed on a framed wall. Make sure that
the horizontal centerline of these holes is
level. Holes “C” and “D” may also be drilled
at this time, or after the boiler is hung on the
wall. If the 5/16 x 2 in. lag screws are used,
TOP EDGE OF BOILER
'HOLE C'
'HOLE A'
'HOLE D'
LEFT SIDE OF BOILER
1.0" MIN. CLEARANCE TO COMBUSTIBLE
10.0" MIN. CLEARANCE TO COMBUSTIBLES
16
253
4
WALL MOUNTING BRACKET
CENTER LINE
BOTTOM SECURING
BRACKET CENTER LINE
2.0" MIN. CLEARANCE TO COMBUSTIBLE
'HOLE B'
3
16" DIA. PILOT HOLES
FOR 5
16" LAG SCREWS
(4 PLACES)
Figure 2C: Wall Mounting Hole Location / Layout
drill 3/16 in. pilot holes.
g. An alternate way to locate/mark holes “A”
and “B” is to use template P/N 102986-01
enclosed into Vent Part Carton [P/N 102981-
01
(ALP080BW/105BW) or P/N 102981-02
(ALP150BW/210W)], which can be found
inside boiler carton.
h. Attach the wall hanging bracket using
the 5/16 in. x 2 in. lag screws and 5/16 in.
plated washers, or other suitable anchors
as appropriate (Figure 2D). Make sure the
bracket is level.
i. Attach Bottom Securing Bracket to boiler air
box with two #8 x ½ in. Phillips round head
sheet metal screws. Refer to Figure 2D for
details.

14 103448-10- 6/18
III. Pre-Installation and Boiler Mounting G. General (continued)
Figure 2D: Bottom Mounting Bracket Installation / Boiler Wall Mounting
BOILER
WALL BRACKET
BOTTOM
SECURING
BRACKET
5
16" X 2" LAG
SCREW (4X)
5
16" X 2" FLAT
WASHER (4X)
2 X 4
WALL STUD
16" C/C
BOILER HANGING
BRACKET
BOILER
#8 X 1
2" SMS (2X)
1
2" SHEET
ROCK
BOILER HANGING
BRACKET
BOTTOM
SECURING
BRACKET
m. See Section IV Venting; Paragraph B, 4
“Field Installation of CPVC Vent Pipe - Wall
Mounted Boiler Builds” for instructions on
attaching the vent system to the boiler.
n. After the boiler has been piped, wired,
connected to vent and combustion air
system piping and combustion performance
testing completed per Section IX “System
Start-up”, install Access Panel/Gasket
assembly and secure with provided four
#8 x ½ in. black oxide Phillips head sheet
metal screws. See Figure 2E “Access Panel
and Gasket Installation”.
j. Hang the boiler on the installed wall bracket
as shown in Figure 2D.
k. If not already done in Step (4) locate and
drill holes “C” and “D” using the ob-round
slots in the Bottom Securing Bracket.
Secure the Bracket to the wall using the
5/16 in. x 2 in. lag screws and 5/16 in.
plated washers, or other fasteners as
appropriate (Figure 2D).
l. Verify that the front of the boiler is plumb.
If it is not, install shims (installer provided)
at holes “C” and “D” between the Bottom
Securing Bracket and the wall to adjust.
CAUTION
The outer edges of the
template represent minimum side, top and
bottom clearances to combustible material.
If the template needs to be cut to fit into
a selected location, it would indicate the
minimum clearances to combustible material
are not met.
When positioning the template
in the desired location on the wall insure
that the minimum clearances to combustible
material at adjacent walls and ceiling are
maintained. Consult Figures 2A through 2C
in this manual. Be sure to allow space at the
boiler left side for gas and water connections,
as well as for access to the condensate trap
and boiler controls for servicing.
CAUTION
Vent pipe must be inserted
firmly into vent connector and secured by
tightening the metal strap worm screw.
WARNING
Vent pipe must be inserted
firmly into vent connector and secured by
tightening the metal strap worm screw.
WARNING

103448-10 - 6/18 15
Figure 2E: Access Panel and Gasket Installation
III. Pre-Installation and Boiler Mounting G. General (continued)
H. Boiler Stacking
1. For installations with unusually high space
heating and/or domestic hot water heating
loads, where employing two (2) Alpine boilers
will offer the benefits of greater operational
efficiency, floor space savings and boiler
redundancy, the Alpine boilers may be
installed stacked one on the top of the other.
Refer to Table 3 “Alpine Boiler Model Stacking
Combinations” for details.
Table 3: Alpine Boiler Model Stacking
Combinations
Bottom
Boiler Model Top Boiler Model (2)
ALP080B (1) ALP080B
ALP105B (1) ALP080B or ALP105B
ALP150B (1) ALP080B through ALP150B
ALP210B (1) ALP080B through ALP210B
ALP285B ALP080B, ALP105B, ALP150B & ALP285B
Notes: (1) Floor-mounted builds only
(2) Floor-mounted or wall-mounted build where applicable
2. To field assemble individual Alpine boilers
into a stackable configuration, use the steps
below:
a. Position the bottom boiler first. Refer to
Sections II “Unpacking Boiler” and III “Pre-
Installation & Boiler Mounting” of the manual
for details. Always position higher input
boiler model as bottom boiler.
b. Each Alpine boiler is factory packaged
with two (2) Stacking Boiler Attachment
Brackets (P/N 101679-01) and the bracket
mounting hardware [six (6) self-drilling hex
washer head plated #8 x ½” long screws,
P/N 80860743]. Locate and remove the
brackets and the hardware. The Stacking
Boiler Attachments Bracket has three 7/32”
diameter holes punched in a triangular
pattern. See Figure 3 “Stacking Boiler
Attachment Bracket Placement”.
c. Alpine boiler left and right side panels have
a series of dimples at panel top and bottom.
These dimples are positioning dimples
for Stacking Boiler Attachment Bracket
mounting screws. Side panel bottom
positioning dimples are evenly spaced from
boiler front and back, while side panel top
positioning dimples follow specific pattern
to compensate for Alpine boiler model
variable depth.
d. Position the upper boiler on the top of the
bottom boiler and align boiler front doors
and sides flush with each other.
• Place first Stacking Boiler Attachment
Bracket onto the upper boiler left side
panel, at the panel lower left corner
and align bracket two upper holes
with corresponding side panel lower
dimples.
• The remaining lower bracket hole must
align with a matching bottom boiler left
side panel top positioning dimple.
• Once bracket holes and side panel
dimple alignment is verified, attach the
bracket to top and bottom boiler left
side panels with the mounting screws.
e. Repeat above procedure to install second
Stacking Boiler Attachment Bracket and
secure the stacked boiler right side panels
together at the front right corner.
f. Install the third Stacking Boiler Attachment
Bracket to secure top and bottom boiler left
side panels at the rear left corner. Align
the bracket holes with corresponding
positioning dimples in the top boiler and
bottom boiler left side panels, then secure
bracket with the screws.
g. Repeat above procedure to install the forth
Stacking Boiler Attachment Bracket to
secure stacked boiler right side panels at
the rear right corner.
3. When installing stackable boiler
combinations observe the following
guidelines:
a. Venting - Top and bottom boilers must
have their individual vent piping and vent
terminals.

16 103448-10- 6/18
III. Pre-Installation and Boiler Mounting H. Boiler Stacking (continued)
Figure 3: Stacking Boiler Attachment
Bracket Placement
Terminating individual boiler condensate
lines into common pipe prior to drain
disposal is permissible, providing common
pipe has sufficient flow capacity to handle
combined condensate volume of stackable
combination.
b. Gas Piping - Follow instructions in Section
VII “Gas Piping” of the manual for sizing
and installation of an individual boiler.
When common gas piping is sized, insure it
will have adequate capacity for combined
input (CFH gas flow) of the selected
stackable boiler combination.
c. Water Piping and Trim - Follow instructions
in Section VI “Water Piping and Trim” of
the manual for system piping and boiler
secondary piping selection/sizing based
on combined heating capacity and/or
gross output of the selected stackable
boiler combination.Follow instructions of
Section VI “Water Piping and Trim” for each
individual boiler trim installation.
d. Electrical - Follow instructions in Section VIII
“Electrical” of the manual to wire individual
boilers.
For side-wall venting individual model vent
terminals must terminate not closer than
12 inches horizontally and three (3) feet
vertically from each other in order to prevent
combustion air contamination. For vertical
through the roof venting, individual vertical
vent terminals, if level with each other,
must be spaced no closer than 12 inches
horizontally. If vertical terminals cannot
end in one plane, they must be spaced no
closer than three (3) feet horizontally.
If vertical vent terminals cannot end in one
plane, they must be spaced no closer then
three (3) feet horizontally.
Follow instructions in Section IV “Venting”
of the manual for specifics of individual
boiler vent termination. Follow instructions
in Section V “Condensate Disposal” for
each individual boiler flue gas condensate
line construction and condensate disposal.
Asphyxiation Hazard. No
common manifold venting is permitted. Each
boiler must have its own individual vent and
combustion air pipes and terminals.
WARNING

103448-10 - 6/18 17
IV. Venting
Figure 4: Location of Vent Terminal Relative to Windows, Doors, Grades, Overhangs, Meters and Forced Air
Inlets - Two-Pipe System Vent Terminal (Shown) Two-Pipe System Air Intake Terminal (Not Shown)
Asphyxiation Hazard. Failure to vent this boiler in accordance with these instructions
could cause products of combustion to enter the building resulting in severe property damage, personal
injury or death.
Do not use a barometric damper, draft hood or vent damper with this boiler.
Do not locate vent termination under a deck.
Do not locate vent termination where exposed to prevailing winds.
Do not locate combustion air termination where chlorines, chlorofluorocarbons (CFC’s), petroleum
distillates, detergents, volatile vapors or other chemicals are present. Severe boiler corrosion and failure
will result.
Use outdoor air for combustion. Do not obtain combustion air from within the building.
Use specified vent and combustion air pipe diameters. Do not reduce specified diameters of vent and
combustion air piping.
Do not interchange vent systems or materials unless otherwise specified.
Do not apply thermal insulation to vent pipe or fittings.
Moisture and ice may form on surface around vent termination. To prevent deterioration, surface must be
in good repair (sealed, painted, etc.).
Do not allow low spots in the vent where condensate may pool.
The CPVC vent materials supplied with this boiler do not comply with Natural Gas and Propane
Installation Code, CAN/CSA B149.1.S1-07 and are not approved for use in Canadian jurisdictions that
require vent systems be listed to ULC S636-2008. In these jurisdictions, vent this boiler using either
stainless steel Special Gas vent or a listed ULC S636 Class IIB venting system.
WARNING
•
•
•
•
•
•
•
•
•
•
•

18 103448-10- 6/18
IV. Venting A. General Guidelines
A. General Guidelines
1. Listed Vent/Combustion Air Systems
a. Install vent system in accordance with “Venting of Equipment” of the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 or “Venting Systems and Air Supply for Appliances” of the Natural Gas and Propane
Installation Code, CAN/CSA B149.1, or applicable provisions of local building codes. Contact local
building or fire officials about restrictions and installation inspection in your area.
b. The Alpine is a Direct Vent (sealed combustion) boiler. Install vent system in accordance to these
instructions. Combustion air must be supplied directly to the burner enclosure from outdoors and flue
gases must be vented directly outdoors.
c. The following combustion air/vent system options are listed for use with the Alpine boilers (refer to Table
4):
i. Two-Pipe CPVC/PVC Vent/Combustion Air System - Separate CPVC/PVC pipe serves to expel products
of combustion and separate PVC pipe delivers fresh outdoor combustion air. Refer to Part B for
specific details.
ii.Two-Pipe Polypropylene Vent/Combustion Air System - Separate rigid or flexible polypropylene pipe
serves to expel products of combustion and separate rigid polypropylene or PVC pipe delivers fresh
outdoor combustion air. Refer to Part C for specific details.
iii. Two-Pipe Stainless Steel Vent/Combustion Air System - Separate stainless steel pipe serves to expel
products of combustion and separate PVC or galvanized steel pipe delivers fresh outdoor combustion
air. Refer to Part D for specific details.
d. Vent connectors serving appliances vented by natural draft shall not be connected into any portion of
mechanical draft systems under positive pressure.
2. Vent/Combustion Air Piping
a. Do not exceed maximum vent/combustion air lengths listed in Table 5A. Vent/combustion air length
restrictions are based on equivalent length of vent/combustion air pipe (total length of straight pipe plus
equivalent length of fittings). Table 6A lists equivalent lengths for fittings. Do not include vent/combustion
air terminals in equivalent feet calculations. Use vent/combustion air equivalent length worksheet provided
in Table 6B.
b. Maintain minimum clearance to combustible materials. See Figure 2A or 2B for details.
c. Enclose vent passing through occupied or unoccupied spaces above boiler with material having a fire
resistance rating at least equal to the rating of adjoining floor or ceiling.
Note: For one or two family dwellings, fire resistance rating requirement may not need to be met, but is
recommended.
d. Slope horizontal vent pipe minimum 1/4 in/ft (21 mm/m) downward towards the boiler.
Les chaudières de catégories I, II et IV doivent présenter des tronçons horizontaux dont la pente montante
est d’au moins 1/4 po par pied (21 mm/m) entre la chaudière et l’évent.
e. If possible, slope horizontal combustion air pipe minimum 1/4 in/ft (21 mm/m) downward towards terminal.
If not, slope towards boiler.
f. Use noncombustible ¾ in. pipe strap to support horizontal runs and maintain vent location and slope
while preventing sags in pipe. Do not restrict thermal expansion or movement of vent system. Maximum
support spacing is 4 ft. (1.2 m). Avoid low spots where condensate may pool. Do not penetrate any part
of the vent system with fasteners.
Les instructions d´installation du système d´évacuation doivent préciser que les sections horizontales
doivent être supportées pour prévenir le fléchissement. Les méthodes et les intervalles de support
doivent être spécifiés. Les instructions divent aussi indiquer les renseignements suivants:les chaudières
de catégories II et IV doivent être installées de façon à empêcher l´accumulation de condensat: et si
nécessaire, les chaudières de catégories II et IV doivent être pourvues de dispositifs d´évacuation du
condensat.
g. For multiple boiler installations with vertical roof terminals, separate vent pipes from multiple boilers may
be piped through a common conduit or chase so that one roof penetration may be made.

103448-10 - 6/18 19
3. Vent/Combustion Air Terminals
Install venting system components on exterior of building only as specifically required by these instructions
(refer to Figure 4).
a. Use only listed vent/combustion air terminals.
i. Horizontal Sidewall Venting: For models ALP080B thru ALP285B, use coupling for vent terminal and
90° elbow for combustion air intake terminal as shown in Figure 5). Alternate staggered and snorkel
terminations are shown in Figure 6A and Figure 6B.
ii. Vertical Roof Venting: Use straight coupling on vent and two 90° elbows turned downwards for
combustion air as shown in Figure 7A. and Figure 8).
iii.For Alpine boilers factory build prior to January 2016, US Boiler provided PVC tees (3” or 4” as
applicable to specific boiler model) to be used either as vent or air intake terminals.
For Alpine boilers factory build after January 2016, US Boiler provides PVC coupling (2”, 3” or 4” as
applicable to specific boiler model) to be used as vent terminal and PVC 90° elbow (2”, 3” or 4” as
applicable to specific boiler model) to be used as air intake terminal.
Both above listed combinations of vent/air intake terminations are approved/permissible to use per
Intertek Alpine Listing Report No. 3132672CRT-04.
b. Maintain correct clearance and orientation between vent and combustion air terminals.
i. Space center lines of vent and combustion air terminals minimum 12 in. (300 mm) apart. Spacing of
more than 12 in. (300 mm) is recommended.
ii. If possible, locate vent and combustion air terminals on the same wall to prevent nuisance shutdowns.
If not, boiler may be installed with roof vent terminal and sidewall combustion air terminal.
iii. When installed on the same wall, locate vent terminal at same height or higher than combustion air
terminal.
iv. When using tee terminals, do not locate vent terminal directly above air intake as dripping condensate
may freeze on and block intake.
c. Locate bottom of vent and combustion air terminals at least 12 in. (300 mm) [18 in. (460 mm) in Canada]
above the normal snow line and at least 12 in. (300 mm) above grade level.
d. Locate vent and combustion air terminals at least 12 in. (300 mm) from any door, window, or gravity inlet
into the building.
e. Do not install vent terminal directly above windows or doors.
f. Locate bottom of vent terminal at least 3 ft. (900 mm) above any forced air inlet located within 10 ft. (3.0
m).
g. If window and/or air inlet is within 4 ft. (1.2 m) of an inside corner, maintain at least 6 ft. (1.8 m) spacing
between terminal and adjoining wall of inside corner.
h. Locate bottom of vent terminal at least 7 ft. (2.1 m) above a public walkway.
i. Maintain minimum clearance of at least 4 ft. (1.22 m) [6 ft. (1.83 m) in Canada] horizontally from, and in no
case above or below electric meters, gas meters, regulators, and relief equipment.
j. Do not locate the vent terminal under decks or similar structures.
k. Top terminal must be at least 24 in. (609.6 mm) below ventilated eves, soffits and other overhangs. In no
case may the overhang exceed 48 in. (1219.2 mm). Where permitted by the authority having jurisdiction
and local experience, the terminal may be located closer to unventilated soffits. The minimum vertical
separation depends upon the depth of the soffit. See Figure 4 for details.
l. Maintain minimum 12 in. (300 mm) horizontal spacing between vent terminal and a building corner.
m. Under certain conditions, water in the flue gas may condense, and possibly freeze, on objects around the
terminal including on the structure itself. If these objects are subject to damage by flue gas condensate,
they should be moved or protected.
n. If possible, install the vent and combustion air terminals on a wall away from the prevailing wind. Reliable
operation of this boiler cannot be guaranteed if terminals are subjected to winds in excess of 40 mph (64
km/hr).
o. Do not locate combustion air terminal in areas that might contain combustion air contaminates, such as
near swimming pools.
IV. Venting A. General Guidelines (continued)

20 103448-10- 6/18
Table 4: Vent/Combustion Air Intake System Options
IV. Venting A. General Guidelines (continued)
Vent & Intake Materials Option Penetration Through
Structure Termination Figures Component Table
Reference
Section
Standard CPVC/PVC
Two-Pipe, CPVC/PVC
Vent and PVC Air Intake
1Intake Horizontal Sidewall 90° Elbow w/ Screen 5, 6A, 6B 7A, 7B
A.B
Vent Horizontal Sidewall Coupling w/ Screen
2Intake Horizontal Sidewall Ipex Low Profile 6D, 6E 7D
Vent Horizontal Sidewall
3Intake Horizontal Sidewall Ipex FGV Concentric 6G, 6H, 6J 7F
Vent Horizontal Sidewall
4Intake Horizontal Sidewall DiversiTech (HVENT) 6D, 6F 7E
Vent Horizontal Sidewall
5Intake Horizontal Sidewall DiversiTech (CVENT)
Concentric 6G, 6H, 6J 7G
Vent Horizontal Sidewall
6Intake Horizontal Sidewall 90° Elbow w/ Screen 6C 7A, 7B
Vent Vertical Roof Coupling w/ Screen
7Intake Vertical Roof (2) 90° Elbows w/ Screen 7A, 8 7C
Vent Vertical Roof Coupling w/ Screen
8Intake Vertical Roof Ipex FGV Concentric 7B, 6H 7F
Vent Vertical Roof
9Intake Vertical Roof DiversiTech (CVENT)
Concentric 7C, 6H 7G
Vent Vertical Roof
Optional Polypropylene
Two-pipe, Rigid PP
Vent or Flexible PP
Vent (Vertical Only) and
Rigid PP or PVC Air
Intake
10
Intake Horizontal Sidewall UV Resistant 90° Elbow
w/Screen 5, 6A, 6B
8, 9A, 9B,
9C, 9D A, C
Vent Horizontal Sidewall UV Resistant Straight Pipe
w/Screen
11
Intake Horizontal Sidewall UV Resistant 90° Elbow
w/Screen 6C
Vent Vertical Roof UV Resistant Straight Pipe
w/Screen
12
Intake Vertical Roof (2) UV Resistant 90° Elbows
w/Screen 7A, 8
Vent Vertical Roof UV Resistant Straight Pipe
w/Screen
13
Intake Horizontal Sidewall UV Resistant 90° Elbow
w/Screen
16A, 16B
Vent Vertical Roof
Polypropylene Flex Terminal
(B-vent Chase
used for vent only)
14 Intake Vertical Roof Polypropylene Flex Terminal (B-vent Chase used for vent
and air intake)
16D, 16E
Vent Vertical Roof
Optional Stainless Steel
Two-pipe, SS Vent and
Galvanized Steel or
PVC
Air Intake
15
Intake Horizontal Sidewall 90° Elbow w/Screen
5, 6A, 6B
10A, 10B A, D
Vent Horizontal Sidewall Straight Termination
w/Screen
16
Intake Horizontal Sidewall 90° Elbow w/Screen
6C
Vent Vertical Roof Straight Termination
w/Screen
17
Intake Vertical Roof (2) 90° Elbows w/Screen
7A, 8
Vent Vertical Roof Straight Termination
w/Screen
p. For multiple boiler installations with horizontal wall terminals, maintain minimum 12 in. (300 mm) horizontal
distance between adjacent boiler vent terminals. Maintaining greater spacing is recommended to avoid
frost damage to building surfaces where vent terminations are placed.
q. For multiple boiler installations with vertical roof terminals, maintain minimum 12 in. (300 mm) horizontal
distance between adjacent boiler vent terminals.