Camus Hydronics TH082 Setup guide

6226 Netherhart Road, Mississauga, Ontario, L5T 1B7
99-0079
Rev. 0.3
INSTALLATION OPERATION
AND SERVICE MANUAL
GAS FIRED RESIDENTIAL AND COMMERCIAL STAINLESS
STEEL TANK HEATERS
TH SERIES
HOT WATER SUPPLY
Models; TH082 ,102, 152, 202, 252,
292, 392, 502
H
HLW
WARNING:
If the information in these instructions is 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
vapours and liquids in the vicinity of this or any
other appliance.
WHAT TO DO IF YOU SMELL GAS
oDo not try to light any appliance,
oDo not touch any electrical switch; do not
use any phone in your building,
oImmediately call your gas supplier from a
neighbour’s phone. Follow the gas
supplier’s instructions,
oIf you cannot reach your gas supplier, call
the fire department.
Qualified installer, service agency or the
gas supplier must perform installation and
service.
To the
I
nstaller:
After installation, these instructions
must be given to the end user or left on or near the
appliance.
To the End User: This booklet contains important
information about this appliance. Retain for future
reference.
CAMUS HYDRONICS LTD.

TABLE OF CONTENTS
PART 1 GENERAL INFORMATION.......................................................................................................1
1.1 INTRODUCTION.......................................................................................................................1
1.2 SPECIAL INSTRUCTIONS TO OWNER...................................................................................1
1.3 CHECKING EQUIPMENT .........................................................................................................1
1.4 DISPLAY UNIT..........................................................................................................................1
1.5 SEQUENCE OF OPERATION ..................................................................................................1
1.5.2 Heat Transfer Process..............................................................................................................2
1.5.3 End of Sequence......................................................................................................................2
1.6 INSTALLATION CODES...........................................................................................................2
1.7 WARRANTY..............................................................................................................................2
1.8 REMOVAL OF EXISTING APPLIANCE.....................................................................................3
1.9 BOILER/FURNACE ROOM OPERATING CONDITION ............................................................3
1.10 LOCATION OF UNIT.................................................................................................................3
1.11 CLEARANCE FROM COMBUSTIBLE MATERIAL....................................................................4
PART 2 AIR INLET AND VENTING .......................................................................................................7
2.1 GENERAL VENTING GUIDE....................................................................................................7
2.2 CATEGORY IV VENTING (TH 082 – 502) ................................................................................7
2.2.1 Approved Venting Materials Category IV ..................................................................................8
2.3 CATEGORY II VENTING (TH 202 - 502)...................................................................................8
2.3.1 Approved Venting Materials Category II....................................................................................8
2.4 COMBINED COMBUSTION AIR INLET....................................................................................9
2.5 VENT TERMINATION AND AIR INLET CLEARANCES............................................................9
2.5.1 Sidewall Venting.......................................................................................................................9
2.5.2 Sidewall Air Inlet.....................................................................................................................10
2.5.3 Sidewall Concentric Vent/ Air..................................................................................................10
2.6 Vertical Direct Venting.............................................................................................................10
PART 3 GAS CONNECTION............................................................................................................... 12
3.1 GAS CONNECTION...............................................................................................................12
3.2 GAS PIPING ...........................................................................................................................12
3.3 INSTALL PIPING.................................................................................................................... 12
3.4 CHECKING GAS SUPPLY PRESSURE..................................................................................13
3.5 HIGH and LOW GAS PRESSURE SWITCHES (Optional)......................................................13
3.6 AIR/GAS RATIO VALVE .........................................................................................................13
3.7 BURNER.................................................................................................................................14
PART 4 WATER CONNECTION..........................................................................................................15
4.1 INLET AND OUTLET CONNECTIONS ...................................................................................15
4.2 MINIMUM PIPE SIZE REQUIREMENTS.................................................................................15
4.3 HEAT EXCHANGER...............................................................................................................15
4.4 LOW WATER TEMPERATURE SYSTEMS.............................................................................15
4.5 PIPING ARRANGEMENTS.....................................................................................................15
4.5.1 Field Supplied Components....................................................................................................15
4.6 FLOW PROVING DEVICE ...................................................................................................... 16
4.7 T&P RELIEF VALVE ............................................................................................................... 16
4.8 STAINLESS STEEL STORAGE TANK...................................................................................16
PART 5 ELECTRICAL & CONTROLS..................................................................................................16
5.1 ELECTRICAL CONECTIONS..................................................................................................16
5.2 HIGH LIMIT............................................................................................................................. 16
5.3 TH CONTROLLER..................................................................................................................16
5.3.1 Service Parts .......................................................................................................................... 17
5.3.2 Ignition Module Lockout Functions..........................................................................................17
5.4 ERROR TABLE.......................................................................................................................17
5.4.1 Lockout Codes........................................................................................................................17

5.4.2 Alert Codes............................................................................................................................. 17
PART 6 CONTROL PANEL..................................................................................................................18
6.1 TH CONTROLLER..................................................................................................................18
6.2 SETTING THE TH CONTROLLER..........................................................................................18
6.3 DOMESTIC HOT WATER OPERATION ................................................................................. 18
PART 7 COMPONENTS...................................................................................................................... 18
7.1 DIRECT SPARK IGNITER ...................................................................................................... 18
7.2 FLAME SENSOR....................................................................................................................18
7.3 COMBUSTION AIR FAN.........................................................................................................19
7.4 GAS VALVE............................................................................................................................19
7.5 OUTER JACKET.....................................................................................................................19
PART 8 TH CONTROL PANEL............................................................................................................20
8.1 INTRODUCTION TO THE TH CONTROL PANEL .................................................................. 20
8.2 USER MODE ..........................................................................................................................21
8.3 SETUP MODE.........................................................................................................................22
8.4 DIAGNOSTIC MODE .............................................................................................................. 23
8.5 SETTING THE TANK HEATER HS CONTROLLER................................................................25
PART 9 TROUBLESHOOTING............................................................................................................30
9.1 SETTING THE CORRECT COMBUSTION.............................................................................38
9.2 GAS VALVE ADJUSTMENT PROCEDURE............................................................................38
PART 10 MAINTENANCE...................................................................................................................... 40
10.1 EXAMINE THE VENTING SYSTEM........................................................................................40
10.2 VISUALLY CHECK MAIN BURNER FLAMES.........................................................................40
10.3 CLEANING BOILER HEAT EXCHANGER.............................................................................. 41
10.4 CONDENSATE TREATMENT.................................................................................................41
10.4.1 Condensate Volume ...............................................................................................................41
10.5 IGNITER AND FLAME SENSOR ELECTRODES....................................................................42
10.6 CHECK IGNITER GROUND WIRING .....................................................................................42
10.7 BURNER MAINTENANCE ...................................................................................................... 42
10.7.1 Burner Removal and Cleaning................................................................................................42
10.8 REMOVAL OF COMBUSTION CHAMBER LINING ................................................................42
10.9 COMBUSTION AND VENTILATION AIR.................................................................................43
10.10 CONTROL CIRCUIT VOLTAGE..............................................................................................43
10.11 COMBUSTIBLE MATERIALS..................................................................................................43
10.12 FREEZE PROTECTION FOR INDOOR & OUTDOOR INSTALLATIONS................................43
PART 11 INSTALLATIONS....................................................................................................................44
11.1 CHECKING THE INSTALLATION...........................................................................................44
11.2 CHECKING THE CONSTRUCTION........................................................................................44
11.3 INSPECT & RECHARGE CONDENSATE COLLECTION/NEUTRALIZING RESERVOIR.......44
11.4 WATER CONNECTIONS........................................................................................................44
11.5 SUMMARY..............................................................................................................................44
11.6 TEMPERATURE RISE AT FULL FIRING RATE......................................................................45
11.7 SETTING THE CORRECT COMBUSTION.............................................................................45
11.8 APPLIANCE............................................................................................................................45
11.9 IGNITION CYCLE ...................................................................................................................46
PART 12 SUGGESTED PIPING DIAGRAMS ........................................................................................47
PART 13 EXPLODED VIEW & PARTS LIST..........................................................................................48
PART 14 ELECTRICAL DIAGRAMS...................................................................................................... 52
14.1 TH 82- 502 INTERNALWIRING DIAGRAM.............................................................................52
14.2 DETAILED CONNECTOR DESCRIPTION.............................................................................. 53

1
PART 1 GENERAL
INFORMATION
1.1 INTRODUCTION
The TH Series is a fan assisted heater based on a push
through design which offers several venting options. Heat
output is controlled by a one to one air/gas ratio control gas
valve which provides seamless modulation. The heater
provides domestic hot water at working pressures up to 160
PSI. It is designed for use with a fully pumped and
pressurized water system. The water heater will
automatically modulate to provide heat outputs from 100%
down to approximately 20% of rated input.
The TH utilizes a negative pressure gas valve. The
operation of the fan will generate a negative pressure in the
venturi, which draws in a matching amount of gas through
the valve.
During operation the TH maintains a steady state efficiency
across the entire range of modulation. Air and gas are
metered in precise proportion (1:1 Ratio) allowing
combustion characteristics which determine efficiency to
remain the same over the entire operating range.
The TH is designed so that all of the sensible heating value
and most of the latent heat is being transferred to the water.
1.2 SPECIAL INSTRUCTIONS TO OWNER
This manual supplies information for the installation,
operation and servicing of the appliance. It is strongly
recommended that this manual be reviewed completely
before proceeding with an installation
CAUTION
It is important that all gas appliances are installed by a
qualified installer/technician that is trained by Camus
Hydronics. It is in your own interest and that of safety to
ensure that all local codes, and all the following “NOTES”
and “WARNINGS” are complied with.
Installing, servicing or adjusting this appliance should be
performed only by a qualified installer/technician that is
trained by Camus Hydronics. The serviceman must utilize a
combustion analyzer with CO
2
, CO to set the appliance
according to Camus Hydronics’ recommendations, prior to
commission
ing.
NOTE
RETAIN THIS MANUAL FOR FUTURE REFERENCE
1.3 CHECKING EQUIPMENT
Check for signs of shipping damage upon receiving
equipment. Pay particular attention to parts accompanying
the boiler, which may show signs of being hit or otherwise
being mishandled. Verify total number of pieces shown on
packing slip with those actually received. In case there is
damage or a shortage, immediately notify carrier.
1.4 DISPLAY UNIT
The display unit will indicate status and will display selected
temperature. Refer to Part 8 TH Control Panel, which
provides details to modes and error codes displayed on the
appliance.
1.5 SEQUENCE OF OPERATION
1) The power switch is placed in the “ON” position.
2) Minimum 120 VAC 60Hz single phase (15A circuit) is
supplied to the Terminal Strip.
3) 24 VAC power is supplied to the TH Controller which
provides all setup and ignition control functions.
4) A heat request is detected by the DHW Sensor.
5) After the appliance water pump starts, flow is proven
by the flow proving device.
6) The TH Controller initiates a start-up sequence once it
receives a heat demand.
7) Voltage is sent to the electrically commutated DC
motor of the combustion fan after the internal safety
checks are satisfied.
8) The fan will run at Pre-Purge speed until the Pre-Purge
timer is satisfied. Once this is complete the TH
Controller provides a signal to modulate down to
ignition fan speed.
9) The TH Controller supplies voltage to the air/gas ratio
control valve. The air/gas ratio control valve senses the
pressure across the venturi and supplies gas to pre-
mix with air.
10) The igniter will continue to spark for 6 seconds, with
the gas valve opened 2 seconds after the initial spark
is generated with the fan running at ignition speed.
11) Spark igniter lights the air/gas mixture. The TH
Controller looks for a minimum flame rectification
signal of 0.8 µA DC from the flame sensor during the
Main Flame Establishing Period. If the signal is present
the TH Controller will allow the gas valve to remain
open. The burner is now firing at starting input rate.
12) The fan is kept at ignition speed until the stabilization
timer is satisfied.
13) The boiler will modulate to the correct fan speed to
meet the heat demand. The modulation rate is
controlled via Pulse Width Modulation (PWM) signals
provided by the TH Controller.
14) The fan speed will slowly decrease as the heat request
nears the heat demand. If the heat demand is
sustained for a long duration of time the boiler will get
to a point of steady-state and the fan will rotate at a
constant speed.
15) When the heat demand is satisfied or is removed the
burner will shut off and the fan speed will ramp up to
the preset Post-Purge speed until the Post-Purge
Timer is satisfied.
16) The pump continues to circulate until the post-pump
time is satisfied.
17) The boiler will then go into Standby as it waits for the
next heat demand.
Figure 1: TH Ignition Cycle

2
Note:
1. If a flame signal is detected at the end of the pre-purge
period a lockout will occur.
2. If at the end of the safety period (6 sec) no flame is
detected the control will go to post-purge to remove the
unburned gas. After this, a re-ignition attempt is started
following the same cycle. The number of re-ignition
attempts is limited to 2 after which a lockout occurs.
3. The burner can only be on continuously for a period of
24 hours. After this the burner is switched off and a
restart sequence follows.
4. Sparking stops 2 seconds before the end of the ignition
period to allow for ionisation detection.
1.5.2 Heat Transfer Process
1) Burner input continues to increase until DHW water
temperature reaches the setpoint temperature.
2) Burner input may stabilize at a fixed rate where
demand equals input.
3) Burner input will decrease when DHW water
temperature approaches temperature setpoint.
1.5.3 End of Sequence
1) Setpoint temperature is satisfied.
2) Power to the gas valve is turned off.
3) Combustion air fan ramps to a stop over the factory
preprogrammed time period.
WARNING
To minimize the possibility of serious personal injury, fire or
damage to your appliance, never violate the following
safety rules.
DO NOT
Do not use this appliance if any part of it has been
under
water. The possible damage to a flooded appliance can be
extensive and present numerous safety hazards. Any
appliance that has been under water must be replaced
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance. • Do not touch any electric
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.
IMPORTANT
Consult and follow local Building and Fire Regulations and
other Safety Codes that apply to this installation. Contact
the local gas utility company to inspect and authorize all
gas and flue connections.
Installation and service must be per
formed by a
qualified technician/installer, and trained by Camus
Hydronics.
WARNING
Should overheating occur or the gas supply fails to shut off,
DO NOT turn off or disconnect the electrical supply to the
pump. Shut off the gas supply at a location external to the
appliance.
•Boilers and water heaters are heat producing
appliances. To avoid damage or injury, do not store
materials against the appliance or the vent-air inlet
system. Use proper care to avoid unnecessary contact
(especially children) with the appliance and vent-air
inlet components.
•Never cover appliance, lean anything against it, store
trash or debris near it, stand on it or in any way block
the flow of fresh air to appliance.
•UNDER NO CIRCUMSTANCES may flammable
materials such as gasoline or paint thinner be used or
stored in the vicinity of this appliance, vent-air inlet
system or any location from which fumes could reach
the appliance or vent-air inlet system.
•A gas appliance that draws combustion air from the
equipment room where it is installed must have a
supply of fresh air circulating around it during burner
operation for proper gas combustion and proper
venting.
1.6 INSTALLATION CODES
The equipment shall be installed in accordance with
those installation regulations enforced in the local area
where the installation is to be made. These shall be
carefully followed in all cases. Authorities having jurisdiction
shall be consulted before installations are made. In the
absence of such requirements, the installation shall
conform to the latest edition or current as amended of the
National Fuel Gas Code, ANSI Z223.1 and/or CAN/CGA-
B149 Installation Code. All electrical wiring must be done in
accordance with the requirements of the authority having
jurisdiction or, in the absence of such requirements, with
national electrical code, ANSI/NFPA70 and/or the Canadian
electrical code part 1 CSA C22.1. Where required by the
authority having jurisdiction, the installation must conform to
American Society of Mechanical Engineers Safety Code for
Controls and Safety Devices for Automatically Fired Boilers,
ASME CSD-1. All boilers must conform to the latest edition
of the ASME Boiler and Pressure Vessel Code, Section II.
Where required by the authority having jurisdiction, the
installation must comply with the CSA International,
CAN/CGA-B149 and/or local codes. This appliance meets
the safe lighting performance criteria with the gas manifold
and control assembly provided, as specified in the ANSI
standards for gas-fired units, ANSI Z21.10.3b-2008.
1.7 WARRANTY
•Factory warranty (shipped with unit) does not
apply to units improperly installed or improperly
operated.
•Factory warranty shall apply only when the
appliance is installed in accordance with local
plumbing and building codes, ordinances and
regulations, the printed instructions provided with it
and good industry practices.
•Excessive water hardness causing a lime build-
up in the stainless steel coils or tubes is not a fault
of the appliance and is not covered by warranty.
Consult the factory for recommendations for use in
hard water areas. (See Water Treatment and
Water Chemistry)
•Using or storing corrosive chemicals in the
vicinity of this appliance will attack the stainless
steel jacket, the stainless steel venting, heat
exchanger coils, wiring and brass fittings and
voids warranty.

3
•Damage caused by freezing or dry firing voids
warranty.
•This appliance is not to be used for temporary
heating of buildings under construction.
•The manufacturer shall NOT be held liable for any
personal injury or property damage due to ice
formation or the dislodging of ice from the vent
system or the vent termination
1.8 REMOVAL OF EXISTING APPLIANCE
When an existing appliance is removed from a common
venting system, the common venting system is likely to be
too large for proper venting of the appliances remaining
connected to it .At the time of removal of an existing
appliance, the following steps must be followed with each
appliance remaining connected to the common venting
system placed in operation, while the other appliances
remaining connected to the common venting system are
not in operation.
•Seal any unused openings in the common venting
system.
•Visually inspect the venting system for proper size
and horizontal pitch and determine that there is no
blockage, restriction, leakage, corrosion or other
deficiency, which could cause an unsafe condition.
•Insofar as is practical, close all building doors and
windows and all doors between the spaces in
which the appliances remaining connected to the
common venting system are located and other
spaces of the building. If applicable turn on the
clothes dryers and any appliances not connected
to the common venting system. Turn on any
exhaust fans, such as range hoods and bathroom
exhausts, so they will operate at maximum speed.
Do not operate a summer exhaust fan. Close
fireplace dampers.
•Place in operation the appliance being inspected.
Follow the lighting instructions. Adjust thermostat
so that appliance operates continuously.
•Test for spillage at the draft control device relief
opening after 5 minutes of main burner operation.
•After it has been determined that each appliance
remaining connected to the common venting
system properly vents when tested as outlined
above, return doors, windows, exhaust fans,
fireplace dampers and any other gas-burning
appliance to their previous condition of use.
•Any improper operation of the common venting
system should be corrected so that the installation
conforms to the National Fuel Gas Code, ANSI
Z223.1 and/or CAN/CGA B149, Installation Codes.
When resizing any portion of the common venting
system, the common venting system should be
resized to approach the minimum size as
determined using the appropriate tables in Part 11
of the National Fuel Gas Code, ANSI Z223.1 and
/or CAN/CGA B149, Installation Codes.
Heat exchanger surfaces and vent piping should be
checked every six months for deterioration and carbon
deposits. Remove all soot or other obstructions from the
chimney and flue, which might impede draft action. Replace
any damaged or deteriorated parts of the venting system.
A qualified service technician should follow this procedure
when inspecting and cleaning the heat exchanger and vent
pipe.
1) Turn off electrical power and main manual gas shut-off
and allow appliance to cool down.
2) Remove the vent pipe at connection to heat exchanger
and check heat exchanger and vent for obstruction and
clean as necessary.
3) Remove burner from appliance and carefully clean as
required. Never brush or wipe the knitted metal fiber
surface. Use a garden hose or gently wash under the
tap. Vacuum out any deposits found in the heat
exchanger.
CAUTION
Never use a pressure washer or compressed air to clean
the burner.
4) Reinstall parts removed in steps 2 and 3. Be sure that
vent pipe has proper pitch and is properly sealed.
Replace any damaged gasket or refractory. Tighten fan
flange mounting nuts to 3 ft-lb.
5) Restore electrical power and gas supply to appliance.
6) Place appliance in operation using lighting instructions
provided.
7) Confirm proper operation of all safety devices
8) Check for gas leaks and proper vent operation.
NOTE
Experience has shown that improper installation
or
system design, rather than faulty equipment, is the
cause of most operating problems
1.9 BOILER/FURNACE ROOM OPERATING
CONDITION
•Due to low jacket losses from the appliance,
temperatures in the vicinity of the boiler room may drop
significantly; supplemental heat is required to maintain
ambient temperature at minimum of 40ºF.
1.10 LOCATION OF UNIT
Install this appliance in a clean, dry location with adequate
service clearance.
•Do not locate this appliance in an area where it will be
subject to freezing unless precautions are taken.
Radiant losses from the TH are minimal and should not
be relied on to keep the appliance room warm.
•Do not locate this appliance where it may be exposed
to a corrosive atmosphere.
•The appliance should be located close to a floor drain
in an area where leakage from the appliance or
connections will not result in damage to the adjacent
area or to lower floors in the structure, it is
recommended that a suitable drain pan, adequately
drained, be installed under the unit. Under no
circumstances is the manufacturer to be held
responsible for water damage in connection with this
unit, or any of its components.
•If the appliance is installed above the level of the
building’s radiation system, a low water cut-off device
must be installed in the appliance outlet at a minimum
of 3 ft (1M) above the heat exchanger inlet/outlet
connections. Some local codes require the installation
of a low water cut-off on all systems
•When placing the appliance beware that a minimum
clearance of 24” must be provided at the front to allow
easy access to the heat exchanger.

4
•The appliance must be installed so that the ignition
system components are protected from water
(dripping, spraying, etc.) during appliance operation
and service (circulator replacement, control
replacement, etc.)
•Appliances located in a residential garage and in
adjacent spaces that open to the garage and are not
part of the living space of a dwelling unit must be
installed so that all burners and burner ignition devices
have a minimum clearance of not less than 18" (46cm)
above the floor. The appliance must be located or
protected so that it is not subject to physical damage
by a moving vehicle.
•DO NOT install this appliance in any location where
gasoline or flammable vapors are likely to be present.
•Appliance must be installed on a level floor. Maintain
required clearances from combustible surfaces.
•The appliance designed for indoor installation (Indoor
Models) must be installed indoors where it is protected
from exposure to wind, rain and weather.
•The appliance designed for outdoor installation
(Outdoor Models) must be installed outdoors. For
outdoor installations, always consider the use of a
shelter such as a garden shed in lieu of direct
exposure of the appliance to the elements. The
additional protection afforded by the shelter will help to
minimize nuisance problems with electrical
connections and will allow easier servicing of the
appliance under severe weather conditions.
1.11 CLEARANCE FROM COMBUSTIBLE
MATERIAL
This appliance is suitable for alcove (a closet without a
door) installation with minimum clearances to combustibles
as follows:
Table 2: Clearance from Combustibles
Clearances from Combustibles
TOP:
0"
SIDES:
0"
REAR:
12"
VENT (Vent Adapter/
Stainless Steel):
1"
VENT (PVC/CPVC):
0"
FRONT:
6”
Figure 1: TH Clearance from Combustibles
NOTE
Clearances from combustible construction are noted on the
appliance rating plate

5
Table 3: TH Service Clearances
Input [BTU/hr] Service Clearance, Inches (cm)
Front Top Right Side Left Side Rear
80,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61cm) 12” (31 cm)
100,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61cm) 12” (31 cm)
150,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61 cm) 12” (31cm)
199,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61 cm) 12” (31 cm)
250,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61 cm) 12” (31 cm)
299,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61 cm) 12” (31cm)
399,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61 cm) 12” (31 cm)
500,000 24” (61cm) 18” (46cm) 0” (0cm) 24” (61 cm) 12” (31 cm)
Figure 2: TH Model Dimensions
Table 4: Appliance Dimensions and Specifications
Input
[BTU/hr]
Dim.
"A"
[in.]
Dim.
"B"
[in.]
Dim.
“C”
[in.]
Dim.
“D”
[in.]
Dim.
“E”
[in.]
Dim.
“F”
[in.]
Dim.
“G”
[in.]
Dim.
“H”
[in.]
Equivalent
Length of Vent &
Air Intake Pipes at
Recommended Diameter, [in.] Water
Conn.
at
Boiler
[in.]
NPT
Gas
Conn.
at
Boiler
[in.]
NPT
Category IV
CAT.II
Comb.
Vents
Over
25'
and
up to
100'
Over
15'
and
up to
25'
Up
to
15'
80,000 53 22 1/4 46 1/4 46 3/8 47 1/2 8 3/4 9 7/8 7 3/8 3 3 2 - 1 1/2
100,000 53 22 1/4 46 1/4 46 3/8 47 1/2 8 3/4 9 7/8 7 3/8 3 3 2 - 1 1/2
150,000 53 22 1/4 46 1/4 46 3/8 47 1/2 8 3/4 9 7/8 7 3/8 3 3 2 - 1 1/2
199,000 53 31 1/4 37 3/4 46 3/8 47 1/2 12 1/8 9 7/8 7 3/8 3 3 2 4 1 1/2
250,000 53 31 1/4 37 3/4 46 3/8 47 1/2 12 1/8 9 7/8 7 3/8 3 3 2 4 1 1/4 1/2
299,000 65 1/2 31 1/4 37 1/2 58 3/8 53 7/8 12 1/8 11 3/8 8 7/8 4 3 3 5 1 1/4 3/4
399,000 65 1/2 31 1/4 37 1/2 58 3/8 53 7/8 12 1/8 11 3/8 8 7/8 4 3 3 5 1 1/2 1
500,000 65 1/2 31 1/4 37 1/2 58 3/8 53 7/8 12 1/8 11 3/8 8 7/8 4 3 3 6 1 1/2 1

6
Maintain minimum specified clearances for adequate operation. All installations must allow sufficient space for servicing the vent
connections, water pipe connections, circulating pump, bypass piping and other auxiliary equipment, as well as the appliance
Figure 3: TH Service Clearances