Harsco Industrial P-K MACH C1500H Operating instructions

©2010 Harsco Industrial, Patterson-Kelley
Printed : 6/8/2012
MACH®GAS FIRED BOILER
C1500H/C2000H/C2500/C3000/C4000
Natural Gas/Propane/Dual Fuel
Model #:_______ Serial #______________________
Start-Up Date: _______________________
Harsco Industrial, Patterson-Kelley
100 Burson Street
East Stroudsburg, PA 18301
Telephone: [phone]
Toll Free: 877.728.5351
Facsimile: 570.476.7247
www.harscopk.com
MACH®C1500H – C4000
Rev. 1.03 (06/08/2012)
C.S.A Design-Certified
Complies with ANSI Z21.13/CSA 4.9
Gas-Fired Low Pressure Steam and Hot Water
Boilers
ASME Code, Section IV
Certified by Harsco Industrial, Patterson-Kelley
C.S.A Design-Certified
Complies with ANSI Z21.13/CSA 4.9
Gas-Fired Low Pressure Steam and Hot Water
Boilers

MACH®Gas Fired Boiler
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MACH®Gas Fired Boiler
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1.....INTRODUCTION ................................................................................................................................................7
2.....SAFETY..............................................................................................................................................................7
2.1General .............................................................................................................................................7
2.2Training.............................................................................................................................................8
2.3Safety Features ................................................................................................................................8
2.4Safety Labels ....................................................................................................................................8
2.5Safety Precautions ...........................................................................................................................9
3.....INSTALLATION................................................................................................................................................11
3.1Receiving and Storage ...................................................................................................................11
3.2Compliance with Codes..................................................................................................................12
3.3Setup ..............................................................................................................................................12
3.4Electrical Connections ....................................................................................................................13
3.5Inlet Air and Exhaust Venting .........................................................................................................16
3.6Gas Piping ......................................................................................................................................29
3.7Boiler Water Piping .........................................................................................................................31
3.8Pre-Start Check List .......................................................................................................................37
3.9Safety Checks.................................................................................................................................37
3.10Initial Adjustments ..........................................................................................................................39
3.11Fuel/Air Adjustment ........................................................................................................................42
4.....OPERATION.....................................................................................................................................................44
4.1General ...........................................................................................................................................44
4.2Normal Lighting and Shut-Down Procedures .................................................................................45
4.3Emergency Shut-Off .......................................................................................................................46
4.4Typical Boiler Operating Conditions ...............................................................................................46
5.....MAINTENANCE ...............................................................................................................................................47
5.1Maintenance and Inspection Schedule ..........................................................................................47
5.2Cleaning the Burner........................................................................................................................49
5.3Removing the Heat Exchanger.......................................................................................................50
5.4After All Repairs or Maintenance....................................................................................................50
5.5Sequence of Operation...................................................................................................................50
5.6Troubleshooting ..............................................................................................................................51
5.7Manual reset error codes-A##A (OR LOCKING ERROR CODES) ...............................................53
5.8Auto-reset error codes-E## (or blocking error codes) ....................................................................54
6.....PARTS/TECHNICAL SUPPORT .....................................................................................................................55
6.1Wiring Diagrams .............................................................................................................................56
6.2Boiler Parts List...............................................................................................................................69
7.....MACH®BOILER LIMITED WARRANTY.........................................................................................................80
8.....APPENDIX........................................................................................................................................................81
8.1Appendix 1 – MACH®Boiler Fire Test Report................................................................................81
8.2Appendix 2 – MACH®Boiler Maintenance Log ..............................................................................82
8.3Appendix 3 – MACH®Boiler Altitude Derate schedule...................................................................83

MACH®Gas Fired Boiler
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Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
If the information in these instructions are not followed exactly, a fire or explosion may result causing property
damage, personal injury or death.
Do not store or use gasoline or other flammable vapors or liquids in the vicinity of this or any other appliance.
What to do if you smell gas:
Do not try to light any appliance.
Do not touch any electrical switch; do not use any phone in your building.
Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency, or the gas supplier.
AVERTISSEMENT! Assurez-vous de bien suivre les instructions données dans cette notice pour réduire au minimum
le risqué d'incendie ou d'explosion ou pour éviter tout dommage matériel, toute blessure ou la mort.
— Ne pas entreposer ni utiliser d'essence ni d'autres vapeurs ou liquids inflammables dans le voisinage de cet
appareil ou de tout autre appareil.
— QUE FAIRE SI VOUS SENTEZ UNE ODEUR DE GAZ:
• Ne pas tenter d’allumer d’appareils.
• Ne touchez à aucun interrupteur. Ne pas vous servir des téléphones dans le bâtiment où vous vous trouvez.
• Appelez immédiatement votre fournisseur de gaz depuis un voisin. Suivez les instructions du fournisseur.
• Si vous ne pouvez rejoindre le fournisseur de gaz, appelez le service des incendies.
— L’installation et l’entretien doivent être assurés par un installateur ou un service d’entretien qualifié ou par le
fournisseur de gaz.
It is essential to read, understand, and follow the recommendations of this manual
before installing, operating, or servicing this equipment.

MACH®Gas Fired Boiler
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Installation and service must be performed by a qualified and knowledgeable individual
who has been trained on the Harsco Industrial, Patterson-Kelley MACH®boiler. The same features which permit
this boiler to achieve high-efficiency performance make it unlike most other boilers of this general size, so it is
important to understand how this boiler operates.

MACH®Gas Fired Boiler
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MACH®Gas Fired Boiler
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1 INTRODUCTION
This manual describes the installation and operation of MACH® boilers with inputs from 1.5 million through 4 million
BTUH. Natural gas, propane, and dual fuel (natural and propane) units are described. It also includes 208/3/60,
240/3/60, or 480/3/60 voltages for the 3 and 4 million BTUH input boilers. This manual describes the natural gas
design. Information for operation with other fuels is included in the various sections of this manual as applicable. If
you have any questions on the information contained within, or do not fully and completely understand the content,
please contact Harsco Industrial, Patterson-Kelley Technical Service at 570.476.7261 or toll free at 877.728.5351.
The MACH®C1500H/C2000H/C2500/C3000/C4000 gas fired boilers are fully modulating using variable speed
combustion blowers, sophisticated microprocessor controls, modulating gas safety shut off / control valves and a
unique aluminum alloy heat exchanger capable of operating in a fully condensing mode to provide maximum
efficiency in a minimum amount of space. The high quality materials and thoroughly tested design of the boiler should
provide years of trouble free service if the instructions in this manual are followed carefully.
This manual covers the installation of MACH® C1500H/C2000H/C2500/C3000/C4000 natural gas, propane, and dual
fuel (natural gas and propane) boilers. The model number may be followed by a prefix or suffix letter in some cases to
indicate special features or different options.
While details may differ slightly, basic operation is the same for all models. Check the rating plate for correct fuel
usage and gas pressures.
The boiler is only a part of the complete heating system. This boiler may be fully operational and yet because of poor
circulation, control, or other operating characteristics not deliver heat to the desired location. Additional equipment
such as temperature sensors, pumps, flow switches, balancing valves, and check valves will be required for
satisfactory operation of any system. Harsco Industrial, Patterson-Kelley cannot be responsible for the design or
operation of such systems and a qualified engineer or contractor must be consulted.
2 SAFETY
2.1 GENERAL
The MACH®C1500H/C2000H/C2500/C3000/C4000 gas fired boilers must be:
Installed, operated, and serviced in accordance with instructions contained in this manual and other supplemental
manuals.
Installed by qualified personnel in accordance with designs prepared by qualified facility engineers including:
structural, mechanical, electrical, and other applicable disciplines.
Operated and serviced in accordance with a comprehensive safety program determined and established by the
customer. Do not attempt to operate or service until such a program has been established.
Operated and serviced by experienced, qualified, and properly trained personnel in accordance with all applicable
codes, laws, and regulations.
NOTICE! Each safety device must be maintained and checked per the recommended schedule. Refer to Section
5.1 of this manual.

MACH®Gas Fired Boiler
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2.2 TRAINING
Proper training is the best protection against accidents.
It is essential to read, understand, and follow the
recommendations of this manual before installing, operating,
or servicing this equipment. Failure to do so could result in
fire or explosion and serious injury, death, and/or property
damage.
Operating and service personnel must be thoroughly familiar with the basic construction of the MACH®
C1500H/C2000H/C2500/C3000/C4000 boilers, the use and locations of the controls, the operation of the boilers,
adjustment of their various mechanisms, and all applicable safety precautions. If any of the provisions of this manual
are not fully and completely understood, contact Harsco Industrial, Patterson-Kelley Technical Service at
570.476.7261 or toll free at 877.728.5351.
2.3 SAFETY FEATURES
It is the responsibility of the customer to maintain the safety features, such as but not limited to: guards, safety labels,
safety controls, interlocks, lockout devices, in place and operable.
2.4 SAFETY LABELS
The following words are used in this manual to de-note the degree of seriousness of the individual hazards.
Indicates an imminently hazardous situation which, if not avoided, will result in death or
serious injury. This signal word is to be limited to the most extreme situations.
Indicates a potentially hazardous situation which, if not avoided, could result in death or
serious injury.
Indicates a potentially hazardous situation which, if not avoided, may result in minor or
moderate injury. It may also be used to alert against unsafe practices.
NOTICE/NOTE - NOTICE is the preferred signal word to address practices not related to personal injury. The safety
alert symbol is not used with this signal word.

MACH®Gas Fired Boiler
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The safety labels shown above are affixed to your boiler. Although the labels are of high quality, they may become
dislodged or unreadable over time. Contact Harsco Industrial, Patterson-Kelley at 570.476.7261 or toll-free at
877.728.5351 for replacement labels.
2.5 SAFETY PRECAUTIONS
Provide a suitable location for the boiler, away from normal personnel traffic, with adequate working space, adequate
clearances, proper ventilation and lighting, with a structure sufficiently strong and rigid to support the weight of the
boiler, all piping, and accessories.
2.5.1 Electrical Hazards
Shock hazard! Properly lockout/tag out the electrical service and all other
energy sources before working on or near the boiler.
Shock hazard! Do not spray water directly on this boiler or on any electrical
components.
Electrical hazard! Do not alter wiring connections.
2.5.2 Burn, Fire, and Explosion Hazards
Burn, fire, and explosion hazards! Installation must be in strict conformance to all
applicable codes and standards including NFPA 54, ANSI Z223.1 and CAN/CSA
B.149. Install all required vent lines for gas devices. Refer to Section 3.6.
Hazard from incorrect fuels! Possible fire, explosion, overheating, and damage. Do
not use any fuels except the design fuels for the unit.
Over fire hazards! High pressure in gas supply could result in over firing of this or
other devices supplied from the same source.
Fire and explosion hazards! Close the main gas shutoff before servicing boiler.
Fire and explosion hazards! Do not store or use gasoline or other flammable vapors
or liquids in the vicinity of this or any other gas fired appliance.
Burn hazard! Possible hot surfaces. Do not touch gas vent during firing operation.
Use only factory recommended vent components.
Burn hazard! Pipes, vents, and boiler components could be hot. Do not touch piping
or stack surfaces during operation or immediately after shutdown of the boiler.
Burn hazard! Hot fluids. Use caution when servicing or draining boiler.
Hot Surface
Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241
General Warning
Reorder No. 6020-V2WHPK
Improper use may
result in fire or injury.
Read instructions/safety
manual before installing,
operating or servicing boiler.
c
!
WARNING
1998 HCS, Inc. 800-748-0241

MACH®Gas Fired Boiler
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Fire and explosion hazards! Use caution when servicing burner. Propane (LPG) is heavier than air and may
linger in the combustion chamber, vent lines, or elsewhere.
Gas leak hazard! Make sure the burner is installed correctly and blower/transition is securely fastened following
any maintenance performed on them. These connections may leak gas if assembled incorrectly.
Gas leak hazard! All threaded gas connections must be made using a pipe compound that is resistant to liquefied
petroleum gas. Do not use Teflontape on threaded gas piping.
Gas leak hazard! Check entire gas train for leaks after installation. If there is a smell of gas, shut down the boiler
and obtain immediate assistance from trained service personnel and/or your local fire department.
Over fire hazard! Possible fire and explosion from excess gas pressure. Make sure that gas inlet pressure does
not exceed 14 inches W.C.
Over fire hazard! Possible fire and explosion. Possible malfunction of regulators and/or gas safety shut off /
control valves. Maintain all gas train components in good condition. Do not alter wiring connections. Annual
inspection by factory-trained personnel for proper set-up and operation is recommended.
Over fire and under fire hazards! Possible fire, explosion, overheating, and component failure. Do not attempt to
adjust firing rate of the boiler. The firing rate must be adjusted only by factory trained personnel.
Gas may lose its odor. Proper gas sensing equipment and procedures should be used for
leak checks.
2.5.3 Crush Hazards
Lifting hazards! Use properly rated lifting equipment to lift and position the boiler. The
load is unbalanced. Test balance before lifting 3 ft. above the floor. Do not allow
personnel beneath the lifted load. Refer to approximate weights in the table.
Bump hazard from overhead ductwork and piping. Install components with adequate
vertical clearance.
2.5.4 Chemical Hazards
• Chemical hazards from cleaning products. Use caution when cleaning the system. The
use of professional assistance is recommended. Use safe procedures for the disposal of
all cleaning solutions.
• Combustion Condensate – an acidic pH of approximately 3.0 to 5.0 can be expected.
Use PVC, CPVC, or other corrosion resistant piping for drainage. Collection and disposal
must be in accordance with all applicable regulations. A condensate neutralization kit is
available. Please contact your local Harsco Industrial, Patterson-Kelley representative.
Boiler Size Weight in Pounds
C1500H 1,200 lbs
C2000H 1,400 lbs
C2500 1,550 lbs
C3000 1,600 lbs
C4000 1,900 lbs
General Warning
General Warning

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2.5.5 Pressure Hazards
Pressure hazard! Hot fluids. Install isolation valves on boiler water inlet and outlet.
Make sure isolation valves are closed before servicing boiler.
Pressure hazard! Hot fluids. Annually test safety relief valve for proper operation. Do
not operate boiler with faulty relief valve.
2.5.6 Slip, Fall Hazards
Tripping hazard! Do not install piping on floor surfaces. Maintain clear path around
boiler.
Slip and fall hazard! Use drip pan to catch water while draining the boiler. Maintain dry
floor surfaces.
Slip and fall hazard! Do not locate intake or exhaust terminations directly above a
walkway; dripping of condensation can cause icing of the walking surface. (see section
3.5)
Fall hazard! Do not stand on boiler.
3 INSTALLATION
Installation and service must be performed by a qualified installer, service agency, or
gas supplier.
3.1 RECEIVING AND STORAGE
3.1.1 Initial Inspection
Upon receiving the boiler, inspect it for signs of shipping damage. Since some damage may be hidden, unpack
the boiler, open the front, and side doors and inspect the boiler. Verify that the total number of pieces shown on the
packing slip agrees with those actually received.
NOTICE! Note any damage, suspected potential damage, or shortage of materials on the freight bill and immediately
notify the carrier. File all claims for shortage or damage with the carrier. Claims for hidden damages must be filed
with your carrier within 7 days. The boiler carton is equipped with a “Tip (N) Tell”. If "Tip (N) Tell” arrow point is blue,
that indicates that the package has been on its side or tipped over in transit.
3.1.2 Storage Prior to Installation
If the boiler is not installed immediately, it must be stored in a location adequately protected from the weather,
preferably indoors. If this is not possible, then it should remain in the shipping container and be covered by a
tarpaulin or other waterproof covering.
NOTICE! Controls and other equipment that are damaged or fail due to weather exposure are not covered by
warranty.
General Warning
General Warning

MACH®Gas Fired Boiler
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3.2 COMPLIANCE WITH CODES
MACH®boilers with standard components and with many options complies with American National Standard/CSA
Standard ANSI Z21.13/CSA 4.9, latest edition, Gas Fired Low Pressure Steam and Hot Water Boilers.
The heat exchanger is constructed and stamped in accordance with ASME Boiler and Pressure Vessel Code, Section
IV for 125 psig maximum operating pressure.
Installation of the boiler must conform to all the requirements of all national, state and local codes established by the
authorities having jurisdiction or, in the absence of such requirements, to the National Fuel Gas Code, ANSI
Z223.1/NFPA 54 latest edition in the U.S. In Canada, the equipment shall be installed in accordance with the current
Installation Code for Gas Burning Appliances and Equipment, CAN/CSA-B.149, latest edition, and applicable
Provincial Regulations for the class, which should be carefully followed in all cases. Authorities having jurisdiction
should be consulted before installations are made.
Where required by local codes, the installation must conform to American Society of Mechanical Engineers Safety
Code for Controls and Safety Devices for Automatically Fired Boilers (ASME CSD-1).
In the Commonwealth of Massachusetts (a) this unit must be installed by a licensed pipe fitter / plumber, (b) field
installed gas cocks must be “T” handle type, (c) piping of condensate shall conform to the State Plumbing Code, and
(d) refer to the Massachusetts Supplement for further details.
3.3 SETUP
3.3.1 Foundation and Placement
Provide a firm, level foundation, preferably of concrete.
The wheels provided with this boiler are for positioning purposes only. When positioning
this boiler, maintain positive control of it at all times. Do not attempt to move the boiler on surfaces that are not
level. Failure to heed this warning could result in personal injury or death.
Lifting the front of the boiler slightly will allow the boiler to be rolled off the shipping skid onto the concrete foundation.
Once in position, the wheel bolts may be removed allowing the wheels to recess up into the boiler. The base will sit
flat on the provided foundation. All of our boilers are supplied with leveling feet to adjust the boiler to a level position
on the floor. This is very important to maintain proper condensate drainage and correct operation of the boiler. If the
boiler is to be pulled out for maintenance, the wheels may be left attached.
3.3.2 Placement
The boiler must be level to function properly. There are six 9/16” holes in the base that may be used for 3/8” seismic
anchors.
NOTICE! The boiler may be installed on a combustible floor; however, the boiler must never be installed on carpeting.
3.3.3 Clearances
If the boiler is to be installed near combustible surfaces, the minimum clearances shown in the pictures and table
below must be maintained. Failure to provide for the service access clearances, even with non-combustible surfaces,
may cause future problems servicing the boiler. Maintain a clearance from the vent to combustible surfaces of 18” or
as specified in the vent manufacturer’s listed installation instructions. The boiler must be installed in a space large in
comparison to the boiler as described in the National Fuel Gas Code, ANSI Z223.1, latest edition.

MACH®Gas Fired Boiler
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Minimum Clearances from Adjacent Walls, Ceiling, and Obstructions
Type of Surface Dimensions (inches)
A B C† D
Combustible Surfaces
Minimum Clearances
18 6 12 6
Recommended Clearances
for Service Access
30 12* 12 18**
† "C" Space required for pipes, ducts, etc. in this area above the boiler.
* “B” Clearance depends upon exhaust vent configuration.
** Do not put pipes, ducts, vents, etc in this space. Electrical conduit must be installed vertically so that the side
doors can be opened.
Bumping hazard from overhead ducts! Install all components with adequate vertical
clearances.
3.4 ELECTRICAL CONNECTIONS
Be sure to check the nameplate on the boiler before connecting electrical supply.
A
C
B D D D

MACH®Gas Fired Boiler
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Power Input Junction Box
For the C3000 and C4000
NOTICE! A dedicated earth ground (green wire) is required to avoid nuisance shutdowns. Do not ground through
the conduit.
MACH©C1500H/C2000H/C2500 boilers require 120 volts, single phase, 60 hertz electrical service.
The MACH©C3000/C4000 boilers require either 208VAC/ 240VAC OR 480VAC three phase, 60 hertz
NOTE: MACH®C3000/C4000 boilers must be ordered as either 208/240VAC or 480VAC THIS IS NOT FIELD
CONFIGURABLE.
If 208 VAC is used the step down transformer must be reconfigured for 208VAC by changing the connection on the
transformer located inside of the power input junction box (see MACH® boiler transformer wiring diagrams for proper
configuration).
The total operating amperage is indicated on the rating nameplate. Before starting the boiler, check to ensure that the
proper electrical service is connected to the boiler.
An external electrical disconnect (not supplied with the boiler) is required. The boiler electrical service must be
installed and grounded in accordance with local codes or in the absence of such requirements, in the U.S. with
National Electrical Codes, ANSI/NFPA No. 70 latest edition or, in Canada, to the Canadian Electrical Code, Part I,
CSA C22.1, latest edition. Installed conduit must not block openings and must allow the side doors to be opened.
The electrical junction boxes are located at the upper front sides of the boiler.
The MACH®C3000/C4000 boilers have an added electrical junction box at the
lower front left side.
3.4.1 Power Input Junction Box MACH© C3000/C4000 Boilers
The main power connections are connected to the over current safety device
rated for a 20 Amp 3 phase circuit (for either 208-240 or 480VAC) and ground
terminal located in the main power connection box. This box is located at the
lower front left side of the boiler. The power connection has four points of
contact: Terminals 1, 3, 5 and G. Connect the three wires supplying the three
phase power to terminals 1, 3 and 5. Connect the main boiler ground wire to
G.
The MACH©C3000/C4000 boilers internal control transformer is pre-wired
from the factory for operation with 240 VAC or 480VAC. If 208 VAC three
phase power is used on the 240VAC model, the internal control transformer
must be wired for operation at this lower voltage. The wire in terminal X3 on
the load side of the internal control transformer must be moved to terminal X4.
This supplies the 120 VAC power to the controls from the 208 VAC main
voltage. Refer to Sections 6.1.4 and 6.1.5 for proper wiring and configuration
of the internal control transformer.
3.4.2 Power Input Junction Box or Terminal Block 2 (TB2) MACH© C1500H/C2000H/C2500 Boilers
The main power connection is made within the TB2/HV terminal block to terminals:
1 - 120VAC LINE L1+
2 - 120VAC NEUTRAL N1 -
8 - GROUND G

MACH®Gas Fired Boiler
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3.4.3 High Voltage (TB2) Terminal Block
For MACH®C3000/C4000 boilers, the high voltage (TB2) terminal block is for 120VAC
output pilot duty loads only. Do not connect any 120VAC supply voltage to the high voltage (TB2) terminal block.
Connecting a 120VAC supply voltage to TB2 can result in serious injury or death.
120 VAC Neutral- These terminals provide the neutral wires for the boiler 120 VAC outputs.
120VAC Switched Output- This contact closes when the boiler is switched on. This provides 120 VAC, 0.5 Amp
service to TB2-10. The neutral for this circuit is provided on TB2-3. When the boiler is switched off, this terminal is
switched off as well.
3 Way Valve- This output is normally energized, keeping the three way valve open, providing heat to the building.
The Domestic Hot Water (DHW) call for heat de-energizes this circuit, causing the 3 way valve to self close, thereby
providing heat to the DHW loop. This output provides 120 VAC, 0.5 Amp service to TB2-11. The neutral for this
circuit is provided on TB2-4. Note: the 3 way valve is a field sourced part.
DHW Pump Relay w/ Delay Off - This output is enabled when there is a call for DHW. When the call for heat is
removed, the output remains enabled for the post pump time parameter within the DHW settings. This output
provides 120 VAC, 0.5 Amp service to TB2-12. The neutral for this circuit is provided on TB2-5.
Circ Pump Relay w/ Delay Off - This output is enabled when there is a call for heat. When the call for heat is
removed, the output remains enabled for the post pump time parameter within the CH settings. This output provides
120 VAC, 0.5 Amp service to TB2-13. The neutral for this circuit is provided on TB2-6.
Damper Relay - This output is enabled when the call for heat is enabled. This output provides 120 VAC service to
TB2-14. The neutral for this circuit is provided on TB2-7. This circuit is for pilot duty only.
Master Alarm Relay – This is a dry set of contacts that are normally open and will close in the event of an alarm
output from the boiler control, connecting TB2-15 and TB2-16.
Flame Detected Relay – This is a dry set of contacts that are normally open and will close whenever the boiler
control is reading a flame, connecting TB2-17 and TB2-18.
TB2 high voltage terminal block
TB1 low voltage terminal block

MACH®Gas Fired Boiler
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3.4.4 Low Voltage (TB1) Terminal Block
Enable/Disable– TB1-1 and TB1-2 are used for enabling the boiler. Closing this circuit allows the boiler to run.
Opening this circuit prevents the boiler from running. This circuit is energized by the boiler. It has a 24 VAC potential.
Devices connected to these terminals must be rated for 24 VAC
Note: This circuit will become unusable in certain CH modes and Cascade Master Modes dealing with 0-
10vdc.
External Interlock – TB1-3 and TB1-4 are used for attachment of an additional field safety device to the boiler control
circuit. Closing this circuit allows the boiler to run. Opening this circuit prevents the boiler from running. This circuit is
energized by the boiler with a 5 V potential. Devices connected to these terminals must be rated for 5 V.
Outdoor Temp Sensor – TB1-5 and TB1-6 are connected to the outdoor temperature sensor. The temperature
control must be programmed to run an outdoor air schedule. The outdoor air sensor and programming help are
available from the local Harsco Industrial, Patterson-Kelley Representative. This circuit is energized by the boiler with
a 5 V potential. The temperature sensor must be a NTC having 12 k @ 77°F.
DHW Stat/Sensor – TB1-7 and TB1-8 are connected to the DHW temperature sensor or thermostat. This circuit is
energized by the boiler with a 5V potential. The temperature sensor must be a NTC having 12 k @ 77°F.
Header Temp Sensor – TB1-9 and TB1-10 are connected to the header temperature sensor. This circuit is
energized by the boiler with a 5 V potential. The temperature sensor must be a NTC having 12 k @ 77°F.
DHW Flow Switch – TB1-11 is energized by the boiler with a 5 V potential. This circuit connects through a flow
switch on the domestic side of a domestic hot water system. The flow switch should close upon flow to provide a
closed circuit back to TB1-12.
Analog Input– Remote signal for controlling the boiler. The boiler can be operated in a remote setpoint or a remote
firing rate control mode. Input 0-10 VDC+ signal on TB1-13 only. The 0 VDC- Analog Input is provided on TB1-14.
The temperature control must be programmed to run with the analog input. (See the ENVI®Control Advanced Users
Guide for more information)
MODBUS® – TB1-17 and TB1-18 are used for connecting a MODBUS® building management system. (See the
ENVI®Control Advanced Users Guide for more information)
Cascade – TB1-19 and TB1-20 are used to connect between boilers that are part of a Master/Member Network. Up to
24 boilers may be connected together. (See the ENVI®Control Advanced Users Guide for more information)
3.5 INLET AIR AND EXHAUST VENTING
3.5.1 Applicable Codes & Standards
CODES
United States:
NFPA 54/ANSI Z223.1 National Fuel Gas Code
NFPA/ANSI 211 Chimneys, Fireplaces, Vents and Solid Fuel Burning Appliances
Canada
CAN/CSA B149.1 Installation Codes for Gas Burning Equipment
STANDARDS
UL 1738 Venting Systems for Gas-Burning Appliances, Categories II, III, and IV
ULC S636-95 Standard for Type BH Venting Systems
Sheet Metal and Thermoplastic Duct Construction Manual
Air Conditioning Contractors National Association (SMACNA)

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These codes and standards contain information for the venting of gas fired appliances, including, but not limited to
vent sizing, location, clearance to combustibles, and safe installation practices. The installation must comply with
both the above Federal Codes and with state, provincial and local codes.
Design and installation of venting systems should be done only by qualified and
knowledgeable venting systems personnel and in accordance with vent system manufacturer’s installation
instructions. Installing a boiler or vent system using improper installation methods or materials can result in serious
injury or death due to fire or asphyxiation.
Before connecting a boiler to a venting system, it must be determined whether the boiler
is to be installed in a conventional or Direct Vent configuration. In the US, provisions for combustion and ventilation
air must be in accordance with NFPA 54/ANSI Z223.1, National Fuel Gas Code, latest edition, or applicable
provisions of the local building codes. In Canada, combustion and ventilation air openings shall comply with
CAN/CSA B-149.1 Natural Gas and Propane Installation Code.
For correct installation of vent system, read all of these instructions and refer to vent
manufacturer’s instructions.
Failure to use a proper vent system (types and materials), as described in this manual will void the boiler warranty
and may result in rapid deterioration of the venting system, creating a health or life safety hazard.
Faulty vent installation can allow toxic fumes to be released into living areas. This may cause property damage,
serious bodily injury or death.
Table of Required Stainless Steel Vent Adapters and Category II Motorized Dampers
NOTICE! This table is for information only. Combustion air dampers and vent adapters are listed for use of design
and may or may not be specific to your application.
The optional, but required for Category II venting, normally-closed motorized combustion air damper operates on 120
VAC and features an end limit switch wired into the boiler’s external interlock circuit. Upon a call for heat, the boiler’s
Boiler
Size Nominal vent Size
Stainless
Vent Adapter Vent adapter
size
Boiler air
inlet for
combustion
air
Combustion
air Normally-
Closed
Motorized
Damper
A
C300 4” 2600000593
4” 6”
1004906943 6”
C450 5” 2600000594
5” 6”
1004906943 6”
C750 6” 2620000181
8”x6” 6”
1004906943 6” size
C900 8” 2620000366
8” 6”
1004906944 8” as
C1050 8” 2620000366 8” 6” 1004906945 10” needed
C1500 10” 2630000226
10”x8” 10”
1004906945 10” size
C2000 10” 2630000225
10”x8” 10”
1004906945 10” as
C2500 10” 2640000133 10” 12” 1004906946 12” need
C3000 10” 2640000133 10” 12” 1004906946 12”
C4000 10” 2640000133 10” 12” 1004906989 14”

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combustion air damper relay will energize and drive the damper open. Once the damper reaches the fully-open
position, the end limit switch makes contact and closes the external interlock circuit allowing the boiler to fire. The
diagram below shows the wiring necessary to install the normally-closed motorized damper.
Use caution if installing a barometric damper in the exhaust vent. The vent pressure must
be negative from the barometric to the vent termination (Category II) at all times to prevent leakage of harmful flue
gases into the room. Leakage of flue gases can cause serious injury or death. Note: this applies to Category II
venting only.
3.5.1.1 Gas Vent Categories
Several codes and standards have categorized appliances in accordance with the flue gas temperature and pressure
produced by the appliance. The applicable categories are defined as follows:
Category II An appliance that operates with a non-positive vent static pressure and with a vent temperature
that may cause excessive condensate production in the vent.
Category IV An appliance that operates with a positive vent static pressure and with a vent temperature that
may cause excessive condensate production in the vent.
Direct Vent An appliance that is constructed and installed so that all air for combustion is derived directly
from outdoors and all flue gases are discharged to the outdoors.
3.5.1.2 Venting Materials for Flue/Exhaust Systems
The MACH®C1500H/C2000H/C2500/C3000/C4000 boilers are dual certified as a Category II and Category IV
appliance, which vents with a temperature that is likely to cause condensation in the vent. Therefore, any venting
system used with the MACH®boiler must comply with the requirements for either Category II or Category IV venting
systems as specified in the latest edition of NFPA 54/ANSI Z223.1 in the US or the latest edition of CAN/CSA B-149.1
in Canada.
The venting materials listed below are intended for the venting of gas burning
appliances only. Do not use these venting materials for venting liquid or solid fuel (such as oil, kerosene, wood or
coal) appliances
Maintain clearances to combustibles as listed in the vent manufacturer’s installation instructions or as set forth in
the codes and standards listed in this section.
Do not use these vent pipes for incinerators of any sort.

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This boiler is not certified for use with PVC venting. Use of PVC vent may result in vent failure and possible
serious injury or death.
Table of Acceptable Materials for Venting Systems
Table of Applicable Vent Materials
Model Country AL29-4C 316L SS PVC CPVC POLYPROPYLENE
C1500H US X X No X NOTE 3
C2000H US X X No X NOTE 3
C2500 US X X No X NOTE 3
C3000 US X X No X NOTE 3
C4000 US X X No X NOTE 3
C1500H Canada X X No
NOTE 2 NOTE 2
C2000H Canada X X No
NOTE 2 NOTE 2
C2500 Canada X X No
NOTE 2 NOTE 2
C3000 Canada X X No
NOTE 2 NOTE 2
C4000 Canada X X No
NOTE 2 NOTE 2
Note 2: When this material is used for venting, it must be listed to ULC-S636.
Note 3: When this material is used for venting, it must be listed to UL-1738.

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3.5.2 Combustion Air Materials and Sizes
Air Requirements – SCFM
The air intake duct can be fabricated from PVC, CPVC, single wall
galvanized steel, or other suitable materials. The duct must be rigid
enough to maintain the full required cross sectional area under all
operating conditions. Proper sealing of the intake ductwork is necessary
to prevent infiltration of air from conditioned space. Joints in PVC or
CPVC must be cemented. For galvanized duct, wrap each joint and
seam with adhesive aluminum tape or other sealant. The installation of a
bird screen on the intake termination is recommended. Ensure that the
screen does not become blocked with snow, ice, insects etc. Combustion
air duct should be designed with .22”W.C. friction loss per 100’ of duct.
Combustion air must be free from dust, lint, etc. The presence of such materials in the air supplied to the burner
could cause nuisance "Low Air" shutdowns or premature burner failure. The boiler should not be operated during
construction while the possibility of drywall dust, demolition dust, etc. exists.
The combustion air supply must be completely free of chemical fumes which may be corrosive when burned in the
boiler. Common chemicals which must be avoided are fluorocarbons and other halogenated compounds, most
commonly present as refrigerants or solvents, such as Freon, trichloroethylene, perchloroethylene, chlorine, etc.
These chemicals, when burned, form acids which quickly attack the boiler and the boiler stack. The result is improper
combustion and premature boiler failure.
Under no circumstances shall the boiler room ever be under a negative pressure.
Particular care should be taken when exhaust fans, compressors, air-handling units or other equipment may rob air
from the boiler. Note that this equipment might be in rooms other than the boiler room. This applies to both sealed
combustion and atmospheric room combustion air applications.
3.5.2.1 Air Inlet Requirements – United States (NFPA 54/ANSI Z223.1 & NFPA/ANSI 211)
When air is supplied from inside the building, the total required volume shall be the sum of the required volume for all
the appliances located in the mechanical room. Adjacent rooms furnished with fixed openings communicating directly
with the mechanical room are considered part of the required volume. The minimum volume is 50 ft3per 1000 Btu/hr
(4.8 m3/kW) of installed appliance input capacity.
Openings used to connect indoor spaces to obtain the required minimum volume shall be sized as follows:
When rooms are on the same floor, each opening shall have an area equal to 1 square inch for each 1000 Btu/hr
(2200 mm2/ kW) of installed appliance input capacity, but not less than 100 square inches. One opening should
commence less than 12 inches above the floor and the other less than 12 inches below the ceiling. The minimum
dimension of air openings shall be 3 inches.
When rooms are on different floors, each opening shall have an area equal to 2 square inches for each 1000
Btu/hr (4400 mm2/ kW) of installed appliance input capacity.
MACH®Boiler MODEL Required SCFM
C1500H 350
C2000H 467
C2500 584
C3000 629
C4000 839