Columbia MCB50 Owner's manual

P/N 37612101, Rev. B [02/09]
Co l u m b i a bo i l e r Co m p a n y
Main ofces and Factory: Pottstown, PA
MCB SERIES
Cast Iron Gas Fired Boilers
For Forced Hot Water
INSTALLATION, OPERATION &
MAINTANANCE MANUAL
MODEL NUMBERS:
MCB50 MCB75 MCB100
MCB125 MCB150 MCB175
MCB200 MCB250 MCB300

2
INSTALLATION MANUAL AND OPERATING INSTRUCTIONS
IMPORTANT: Read the following instruc-
tions COMPLETELY before installing!!
TABLE OF CONTENTS
C.S.A. Certied
For Natural Gas Or Propane
Tested For 100 LBS.
ASME
Working Pressure
H
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, could result in death, serious injury
or substantial property damage.
WARNING
!
All installations of boilers and venting should be
done only by a qualied expert and in accordance
with the appropriate manual. Installing or venting
a boiler or any other gas appliance with improper
methodsormaterialsmayresultin seriousinjury or
death due to re or to asphyxiation from poisonous
gases such as carbon monoxide which is odorless
and invisible.
WARNING
!
1. Keepboiler area clear and free from combustible
materials, gasoline and other ammable vapors
and liquids.
2. DO NOT obstruct air openings to the boiler
room.
3. Modication, substitution or elimination of fac-
tory equipped, supplied or specied components
may result in property damage, personal injury or
the loss of life.
4. TO THE OWNER - Installation and service of this
boiler must be performed by a qualied installer.
5. TO THE INSTALLER - Leave all instructions with
the boiler for future reference.
6. When this product is installed in the Common-
wealth of Massachusetts the installation must be
performed by a Licensed Plumber or Licensed
Gas Fitter.
WARNING
!
Indicates a potentially hazardous situation which,
if not avoided, could result in minor or moderate
injury or property damage.
CAUTION
!
KEEP THIS MANUAL NEAR BOILER
RETAIN FOR FUTURE REFERENCE
SAFETY SYMBOLS & WARNINGS
The following dened symbols are used throughout this manual
to notify the reader of potential hazards of varying risk levels.
Ratings & Data - Natural Gas & Propane Gas ...3
Installation Procedure.........................................4
Ventilation & Combustion Air ..............................5
Connecting Supply & Return Piping ...................7
Vent Installation ................................................ 11
Vent System Modication ................................. 11
Vent Damper Installation & Instructions............12
Connecting Gas Service...................................13
Electrical Section..............................................13
Wiring Diagram - 24V Standing Pilot................14
Wiring Diagram - Intermittent Ignition...............15
Lighting Instructions..........................................16
Normal Sequence of Operation........................18
General Instructions .........................................18
Checking Gas Input Rate To Boiler ..................20
Replacement Parts......................................22-27

3
RATINGS & DATA - NATURAL GAS & PROPANE GAS
Boiler No. Natural Gas
Inlet*
Dimensions Pump size Supply &
Return Tappings
A B C D E F
50 ½" 11⅛" 5½" 4" 30¾" 36¼" 6" 1¼"
75 ½" 15 7½" 5" 30¾" 37¾" 6" 1¼"
100 ½" 15 7½" 6" 30¾" 37¼" 6½" 1¼"
125 ½" 18⅞" 9½" 6" 30¾" 37¼" 6½" 1¼"
150 ½" 18⅞" 9½" 7" 30¾" 37¾" 7" 1¼"
175 ½" 22¾"11½" 7" 30¾" 38¾" 7" 1¼"
200 ½" 22¾"11½" 8" 30¾" 38¾" 8" 1¼"
250 ¾" 265
13
⁄
16"13¼" 8" 30¾" 40¾" 8" 1¼"
300 ¾" 30½" 15¼" 9" 30¾" 42¾" 10" 1¼"
* Propane gas inlet, all units, 1/2"
Boiler
No.
(1)
A.G.A. Input
Btu/Hr.
(1)
Heating
Capacity Btu/Hr.
(1) **
I=B=R
NetOutput
Btu/Hr
(2)
NetRating
Sq. Ft. HW
@ 170
o
No.
of
Burners
(3)
Recommended
Air Cushion
Tank
Water
Content
(Gals.)
50 50,000 42,000 37,000 243 1 15 2.4
75 75,000 63,000 55,000 365 2 15 4.0
100 100,000 83,000 72,000 481 2 30 4.0
125 125,000 104,000 90,000 603 3 30 5.6
150 150,000 124,000 108,000 719 3 30 5.6
175 175,000 143,000 124,000 829 4 30 7.2
200 200,000 165,000 143,000 957 4 30 7.2
250 250,000 205,000 178,000 1189 5 30 8.8
300 299,999 243,000 214,000 1368 6 60 10.4
EXPLANATORY NOTES
--All boilers are design certied for installation on noncombustible oor.
--For installation on combustible oors use combustible oor kit.
--Recommended chimney height 20 feet. In special cases where conditions
permit, chimney height may be reduced to 10 feet. Refer to the latest
revision of NFGC part 11.
--Electric service to be 120 Volts, 15 Amps, 60 Hz.
--The MEA number for the this boiler is 19-79-E.
(1) For elevations above 2000 feet, ratings should be
reduced at a rate of 4% for each 1000 feet above sea
level.
(2) Base on 170° temperature in radiators.
(3) Tank sized for non-ferrous baseboard or radiant panel
systems. Increase size for cast iron baseboard and
radiation.
--Net I=B=R ratings include 15% allowance for normal
piping and pick-up load. Manufacturer should be
consulted on installations having other than normal piping
and pick-up requirements.
** For equivalent square feet of radiation, divide I=B=R
output by 150.
STANDARD EQUIPMENT: Boiler Jacket, Cast Iron Boiler
Battery, High Limit Control, Vent Damper Relay, Theraltimeter
Gauge, Circulator With Return Piping To Boiler, Main Gas
Burners, Combination 24 Volt Gas Control (Includes Automatic
Gas Valve, Gas Pressure Regulator, Automatic Pilot, Safety
Shutoff, Pilot Flow Adjustment, Pilot Filter), A.S.M.E. Relief
Valve, Drain Cock, Spill Switch, Rollout Switch, Automatic Vent
Damper. Not Shown Are: Wiring Harness, Thermocouple,
Non-linting Safety Pilot.
OPTIONAL EQUIPMENT: Intermittent Electric Ignition
Pilot System.

4
Improper installation, adjustment, alteration, service or maintenance can cause
injury or property damage.
INSTALLATION PROCEDURE
The installation must conform to the requirements of the 1.
authority having jurisdiction or, in the absence of such
requirements, to the latest revision of the National Fuel
Gas Code, ANSI Z223. (Available from the American Gas
Association, 8501 E. Pleasant Valley Road, Cleveland,
Ohio 44134). Reference should also be made to local gas
utility regulations and other codes in effect in the area
in which the installation is to be made. When installed
in Canada: The latest revision of the CAN1-B149.1 and/
or B149.2 Installation Codes for Gas-Burning Equipment
and/or local codes.
Where required by the authority having jurisdiction, the 2.
installation must conform to American Society of Me-
chanical Engineers Safety Code for Controls and Safety
Devices For Automatically Fired Boilers, ANSI/ASME
No.CSD-1.
This boiler series is classied as a Category 1 and the 3.
vent installation shall be in accordance with Part 7 of the
National Fuel Gas Code noted above when installed in
the United States. In Canada refer to the CAN1-B149.1
and or B149.2 Installation Codes for Gas-Burning Equip-
ment. Also refer to applicable provisions of the local build-
ing codes.
This boiler has met safe lighting and other performance 4.
criteria with the gas manifold and control assembly on the
boiler per the latest revision of ANSI Z21.13/CGA 4.9.
The boiler shall be installed such that the gas ignition 5.
system components are protected from water (drip-
ping, spraying, rain, etc.) during appliance operation and
service, (circulator replacement, condensate trap, control
replacement, etc.).
Locate boiler on level, solid base as near the chimney 6.
as possible and centrally located with respect to the heat
distribution system as practical.
Allow 24 inches at the front and right side for servicing 7.
and cleaning.
When installed in a utility room, the door should be wide 8.
enough to allow the largest boiler part to enter, or to
permit replacement of another appliance such as a water
heater.
FOR INSTALLATION ON NON-COMBUSTIBLE
9.
FLOORS ONLY - For installation on combustible ooring
special base must be used. (See Replacement Parts Sec-
tion.) The boiler can not be installed on carpeting. Mini-
mum clearances to combustible construction are:
TOP ........................................................... 18 IN.
FRONT ...............................................ALCOVE *
FLUE CONNECTOR ................................... 6 IN.
REAR........................................................... 4 IN.
CONTROL SIDE.......................................... 9 IN.
OTHER SIDE............................................... 3 IN.
NOTE: Greater clearances for access should supersede
fire protection clearances.
* The denition of an Alcove is a three sided space with no
wall in front of the boiler. The ANSI standard for an alcove is
18 inches from the front of an appliance to the leading edge of
the side walls as shown below.
Minimum Clearances to Combustible Construction (as
seen from above)
3"
4"
BOILER
18"
9"
WARNING
!

5
VENTILATION & COMBUSTION AIR
COMBUSTION AIR REQUIREMENTS
(Minimum Square Inches Requirement)
Model
No.
Unconned Area* Conned Area**
Inside
Combustion Air
Outside
Combustion Air Outside Combustion Air
1 Sq. In./1000
Btu/Hr.
(Fig. #3)
1 Sq. In./5000
Btu/Hr.
(Fig. #4)
Vertical Ducts
1 Sq. In./4000
BTU/Hr.
Horizontal Ducts
1 Sq. In./2000
BTU/Hr.
50 100 10 13 25
75 100 15 19 38
100 100 20 25 50
125 125 25 32 63
150 150 30 38 75
175 175 35 44 88
200 200 40 50 100
250 250 50 63 125
300 300 60 75 150
* A space whose volume is not less than 50 cubic feet per 1000 BTU per hour of all
appliances installed in that space (cubic feet of space = height x width x length)
** A space whose volume is less than 50 cubic feet per 1000 BTU per hour of all
appliances installed in that space (cubic feet of space = height x width x length)
Air openings to combustion area must not be obstructed. By following the instructions below,
adequate combustion air can be maintained.
WARNING
!
Ventilation of the boiler room must be adequate to provide 1.
sufcient air to properly support combustion per the latest
revision of the National Fuel Gas Code, ANSI Z223.1.
Figure #1
CHIMNEY OR
TYPE B VENT PIPE
When a boiler is located in an unconned space in a 2.
building or conventional construction frame, masonry or
metal building, inltration normally is adequate to provide
air for combustion and ventilation. However, if the equip-
ment is located in a building of tight construction (See the
National Fuel Gas Code, ANSI Z223.1 latest revision), the
boiler area should be considered as a conned space.
In this case air for combustion and ventilation shall be
provided according to Step 5. If there is any doubt, install
air supply provisions in accordance with the latest revision
of the National Fuel Gas Code.
When a boiler is installed in an unconned space in a
3.
building of tight construction, air for combustion and ven-
tilation must be obtained from outdoors or from spaces
freely communicating with the outdoors. A permanent
opening or openings having a total free area of not less
than 1 square inch per 5000 Btu per hour of total input
rating of all appliances shall be provided. Ducts may be
used to convey makeup air from the outdoors and shall
have the same cross-sectional area of the openings to
which they are connected.
When air for combustion and ventilation is from inside 4.
buildings, the conned space shall be provided with two
permanent openings, one starting 12 inches from the
top and one 12 inches from the bottom of the enclosed
space. Each opening shall have a minimum free area
of 1 square inch per 1000 Btu per hour of the total input
rating of all appliances in the enclosed space, but must
not be less than 100 square inches. These openings must
freely communicate directly with other spaces of sufcient
volume so that the combined volume of all spaces meets
the criteria for an unconned space. (Figure #1)
When the boiler is installed in a conned space and all air 5.
is provided from the outdoors the conned space shall be
provided with one or two permanent openings according
to methods A or B. When ducts are used, they shall be
of the same cross sectional area as the free area of the
area of the openings to which they connect. The minimum
dimension of rectangular air ducts shall be not less than 3
x 3 inches or 9 square inches.
When installing two openings, one must commence with-A.
in 12 inches from the top and the other within 12 inches
from the bottom of the enclosure. The openings shall
communicate directly, or by ducts, with the outdoors or
spaces (crawl or attic) that freely communicate with the
outdoors. One of the following methods must be used to
provide adequate air for ventilation and combustion.

6
VENTILATION AND COMBUSTION AIR
When directly communicating with the outdoors, each 1.
opening shall have a minimum free area of 1 square inch
per 4,000 Btu per hour of total input rating of all equip-
ment in the enclosure. (Figure #2)
Figure #2
CHIMNEY OR
TYPE B VENT
PIPE
When communicating with the outdoors by means of 2.
vertical ducts, each opening shall have a minimum free
area of 1 square inch per 4,000 Btu per hour of total input
rating of all appliances in the enclosed space. (Figure #3)
Figure #3
(DUCT ENDS 1 FT.
ABOVE THE FLOOR)
CHIMNEY OR
TYPE B VENT
PIPE
If horizontal ducts are used, each opening and duct shall 3.
have a minimum free area 1 square inch per 2,000 Btu
per hour of total input rating of all appliances in the en-
closed space. (Figure #4)
Figure #4
CHIMNEY OR
TYPE B VENT
PIPE
One permanent opening, commencing within 12 inches A.
of the top of the enclosure, shall be permitted where the
equipment has clearances of at least 1 inch from the
sides, 1 inch from the back, and 6 inches from the front
of the boiler. The opening shall directly communicate
with the outdoors or shall communicate through a verti-
cal or horizontal duct to the outdoors or spaces (crawl
or attic) that freely communicate with the outdoors. The
openings must have a minimum free area of 1 square
inch per 3000 Btu per hour of the total input rating of all
equipment located in the enclosure. The free area must
be no less than the sum of the areas of all vent connec-
tors in the conned space.
In calculating free area using louvers, grilles or screens
4.
for the above, consideration shall be given to their block-
ing effect. Screens used shall not be smaller than 1/4 inch
mesh. If the free area through a design of louver or grill is
known, it should be used in calculating the size opening
required to provide the free area specied. If the design
and free area is not known, it may be assumed that wood
louvers will have 20-25% free area and metal louvers and
grilles will have 60-75% free area. Louvers and grilles
should be xed in the open position or interlocked with the
boiler so they are opened automatically during the boiler
operation.

7
IMPORTANT: Circulators in the following illustrations are mounted on the system supply side, but
mounting on the system return side is also acceptable practice.
CONNECTING SUPPLY & RETURN PIPING
EXPANSION
TANK
CHECK
VALVE
B
D
FEED
WATER
C
RETURN PIPING
FROM HEATING
AND COOLING
ELEMENT
WATER
CHILLER
SUPPLY PIPING
TO HEATING
AND COOLING
ELEMENT
CIRCULATOR
A
PRESSURE
REDUCING
VALVE
PROPER
BACKFLOW
PROTECTION
DEVICE
GATE
VALVE
PURGE
VALVE
Figure #5
Connect supply and return piping as suggested in Figure 1.
#5 when the boiler is used in connection with refrigerated
systems.
The chilled medium MUST BE PIPED IN PARALLEL A.
with the boiler.
Use appropriate valves to prevent the chilled medium B.
from entering the heating boiler.
- During heating cycle open valves A and B, close
valves C and D.
- During cooling cycle, open valves C and D, close
valves A and B.
Maintain a minimum clearance of one inch to hot water C.
pipes.
When the boiler is connected to heating coils located in air
2.
handling units where they may be exposed to refrigerated
air circulation, the boiler piping system MUST BE sup-
plied with ow control valves or other automatic means
to prevent gravity circulation of the boiler water during the
cooling cycle.
Hot water boilers installed above radiation level must be 3.
provided with a low water cut-off device.
When a boiler is connected to a heating system that 4.
utilizes multiple zoned circulators, each circulator must
be supplied with a ow control valve to prevent gravity
circulation.
Hot water boilers and system must be lled with water 5.
and maintained to a minimum pressure of 12 pounds per
square inch.

8
CONNECTING SUPPLY AND RETURN PIPING
BOILER
WATER INLET
ALTERNATE
CIRCULATOR
LOCATION
TO SYSTEM FROM SYSTEM
CIRCULATOR
SHUT-OFF
VALVE
PRESSURE
REDUCER VALVE
CHECK VALVE
BALL VALVE
3 WAY MIXING
VALVE
AIR SEPARATOR
HOSE BIB
EXPANSION
TANK
BOILER ALTERNATE
CIRCULATOR
LOCATION
TO SYSTEM FROM SYSTEM
V2V1
CIRCULATOR
SHUT-OFF
VALVE
PRESSURE
REDUCER VALVE
CHECK VALVE
BALL VALVE AIR SEPARATOR
ZONE VALVE
EXPANSION
TANK
WATER INLET
SYSTEM
CIRCULATOR
BYPASS PIPING -
AUTOMATIC MIXING VALVE
BYPASS PIPING -
FIXED LOW TEMP ONLY
Figure #6
Bypass piping is an option which gives the ability to adjust 6.
the supply boiler water temperature to t the system or
the condition of the installation. This method of piping,
however, is not typically required for baseboard heat-
ing systems. Typical installations where bypass piping is
used are as follows:
This method is used to protect boilers from condensation A.
forming due to low temperature return water. Generally
noticed in large converted gravity systems or other large
water volume systems. (Figure #6)
These methods are used to protect systems using radi-B.
ant panels and the material they are encased in from
high temperature supply water from the boiler and pro-
tect the boiler from condensation.
NOTE#1: When using bypass piping, adjust
valves V1 & V2 until desired system temperature
is obtained.
NOTE#2: Bypass loop must be same size piping
as the supply and return piping.
7. Installation using circulators and zone valves are shown
in Figures #7-#10. For further piping information refer
to the I=B=R Installation and Piping Guide.

9
ZONE 3
ZONE 2
ZONE 1 (PRIORITY ZONE)
BOILER
ZONE 4
DHW CIRCULATOR
WATER INLET
CIRC 2
CIRC 3
CIRC 4
CIRCULATOR
SHUT-OFF
VA LV E
PRESSURE
REDUCER VALVE
CHECK VALVE
BALL VALVE AIR SEPARATOR
ZONE VALVE HOSE BIB FLOW CONTROL
VA LV E
EXPANSION
TANK
BOILER
DHW
CIRCULATOR
CH CIRCULATOR
PRIORITY ZONE
CIRCULATOR
EXPANSION
TANK
WATER INLET
FLOW CONTROL
VAV L E SHUT-OFF
VA LV E
PRESSURE
REDUCER VALVE
CHECK VALVE
BALL VALVE
AIR SEPARATOR
ZONE VALVE
HOSE BIB
SINGLE ZONE SYSTEM WITH
DHW PRIORITY
MULTIZONE SYSTEM WITH CIRCU-
LATORS AND DHW PRIORITY
CONNECTING SUPPLY AND RETURN PIPING
Figure #7
Figure #8

10
ZONE 3
ZONE 2
ZONE 1 (PRIORITY ZONE)
BOILER
WATER INLET
ZONE 4
*USE FULL PORT ZONE
VALVE.
DHW
CIRCULATOR
CH
CIRCULATOR
CIRCULATOR
FLOW CONTROL
VALVE
SHUT-OFF
VALVE
PRESSURE
REDUCER VALVE
CHECK VALVE
BALL VALVE AIR SEPARATOR
ZONE VALVE HOSE BIB
EXPANSION
TANK
ZONE 3
ZONE 2
ZONE 1 (PRIORITY ZONE)
BOILER
WATER INLET
CH & DHW
SYSTEM
CIRCULATOR
*USE FULL PORT ZONE
VALVE. FOR OPTIMUM TANK
PERFORMANCE, CONSIDER
USING ZONE CIRCULATOR
(SEE FIGURE 5)
ZONE 4
CIRCULATOR
SHUT-OFF
VA LV E
PRESSURE
REDUCER VALVE
CHECK VALVE
EXPANSION
TANK
AIR SEPARATOR
ZONE VALVE HOSE BIB
FLOW CONTROL
VA LV E
Figure #9
Figure #10
CONNECTING SUPPLY AND RETURN PIPING
MULTIZONE SYSTEM WITH
ZONE VALVES AND DHW PRIORITY
(WITH CIRCULATOR)
MULTIZONE SYSTEM WITH
ZONE VALVES AND DHW PRIORITY
(WITH ZONE VALVE)

11
VENT SYSTEM MODIFICATION
VENT INSTALLATION
When an existing boiler is removed from a common vent-
ing system, the system is likely to be too large for the proper
venting of the appliances still connected to it. If this situation
occurs, the following test procedure must be followed:
REMOVAL OF BOILER FROM VENTING SYSTEM
At the time of removal of an existing boiler, the following steps
shall 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 an unused opening in the common venting system.
1.
Visually inspect the venting system for proper size and 2.
horizontal pitch and determine there is no blockage or re-
striction, leakage, corrosion and other deciencies which
could cause an unsafe condition.
Insofar as is practical, close all building doors and win- 3.
dows and all doors between the space in which the
appliances remaining connected to the common venting
system are located and other spaces of the building. Turn
on clothes dryers and any other appliance not connected
to the common venting system. Turn on any exhaust fans,
such as range hoods and bathroom exhausts, so they
operate at maximum speed. Do not operate a summer
exhaust fan. Close replace dampers.
Place in operation the appliance being inspected. Follow 4.
the lighting instructions. Adjust thermostat so appliance
will operate continuously.
Test for spillage at the draft hood relief opening after 5 5.
minutes of main burner operation. Use the ame of a
match or candle, or smoke from a cigarette, cigar or pipe.
After it has been determined that each appliance remain- 6.
ing connected to a common venting system properly
vents when tested as outlined above, return doors, win-
dows, exhaust fans, replace dampers and any other gas
burning appliances to their previous condition of use.
Any improper operation of the common venting system 7.
All installations of boilers and venting should be done only by a qualied expert and in accordance
with the appropriate manual. Installing or venting a boiler or any other gas appliance with improper
methods or materials may result in serious injury or death due to re or to asphyxiation from poison-
ous gases such as carbon monoxide with is odorless and invisible.
WARNING
!
This boiler shall not be connected to any portion of a mechanical draft system operating under
positive pressure.
WARNING
!
The vent pipe must slope upward from the boiler not less 1.
then ¼ inch for every 1 foot to the vent terminal.
Horizontal portions of the venting system shall be sup- 2.
ported rigidly every 5 feet and at the elbows. No portion of
the vent pipe should have any dips or sags.
This boiler series is classied as a Category 1 and the 3.
vent installation shall be in accordance with latest revision
of the National Fuel Gas Code noted above or applicable
provisions of the local building codes.
Inspect chimney to make certain it is constructed ac- 4.
cording to NFPA 211. The vent or vent connector shall
be Type B or metal pipe having resistance to heat and
corrosion not less than that of galvanized sheet steel or
aluminum not less than 0.016 inch thick (No. 28 Ga).
Connect ue pipe from draft hood to chimney. Bolt or
5.
screw joints together to avoid sags. Flue pipe should
not extend beyond inside wall of chimney. Do not install
manual damper in ue pipe or reduce size of ue outlet
except as provided by the latest revision of ANSIZ223.1.
Protect combustible ceiling and walls near ue pipe with
reproof insulation. Where two or more appliances vent
into a common ue, the area of the common ue must
be at least equal to the area of the largest ue plus 50
percent of the area of each additional ue.

12
VENT DAMPER INSTALLATION & INSTRUCTIONS
VENT SYSTEM MODIFICATION
should be corrected so the installation conforms with
the latest revision of the National Fuel Gas Code, ANSI
Z223.1. When resizing any portion of the common venting
system, the common venting system should be resized to
approach the minimum size as determined using the ap-
propriate tables in the latest revision of the National Fuel
Gas Code, ANSI Z223.
DAMPER INSTALLATION
NOTE: Refer to Figure #11 for steps 1-6.
LOCKNUT
HARNESS
CONN.
DAMPER
CONN.
INSTALLER
HOOK-UP
INSTALLER
HOOK-UP
DAMPER
MOTOR
DAMPER
DAMPER
WIRE
HARNESS
FA C T O R Y
WIRED
VENT OUTLET
AQUASTAT
VENT
Figure #11
Place Vent Damper on or as close to vent outlet of boiler 1.
as possible. (Figure #12)
Remove Vent Damper Motor cover. 2.
Feed damper wire harness connector through bracket 3.
hole on Damper Motor frame.
Tighten locknut onto Damper wire harness connector. 4.
Plug Damper connector into socket on Damper Motor 5.
frame.
Replace Damper Motor cover and wire Damper in accor- 6.
dance with Figure #11.
DAMPER INSTRUCTIONS
Ensure that only the boiler is serviced by the Vent Damp- 1.
er. (Figure #12)
ACCEPTABLE VENT
DAMPER LOCATIONS
UN-ACCEPTABLE
DAMPER LOCATIONS
BOILER
HOT WATER HEATER
CHIMNEY
INSTALLATION
POSITION OF DAMPER
X
MANUFACTURER'S
REFER TO DAMPER
INSTRUCTIONS FOR
CONTROL BOX
Figure #12
Clearance of not less than 6 inches between Vent 2.
Damper and combustible material must be maintained.
Additional clearance should be allowed for service of Vent
Damper.
Vent Damper must be in the open position when appli- 3.
ance main burners are operating.
The Vent Damper position indicator must be in a visible 4.
location following installation.
The thermostat's heat anticipator must be adjusted to
5.
match the total current draw of all controls associated with
the boiler during a heating cycle.

13
CONNECTING GAS SERVICE
ELECTRICAL SECTION
Connect gas service from meter to control assembly in 1.
accordance with ANSI Z223.1 and local codes or utility.
A ground joint union should be installed for easy removal
of gas control for servicing. A drip leg or trap must be
installed at the bottom of a vertical section of piping at the
inlet to the boiler. A pipe compound resistant to the action
of liquied petroleum gases must be used on all threaded
pipe connections. Check with the local utility for location
of manual shutoff valve if required. ( Figure #13 )
Figure #13
The gas line should be of adequate size to prevent undue 2.
pressure drop and never smaller than the pipe size of the
main gas control valve. (See Chart)
MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS/HOUR
(Gas Pressure = 0.5 psig or less, Pressure Drop = 5 in. w/c)
Length of
Pipe (Feet)
Nominal Iron Pipe Size
½” ¾” 1” 1¼”
10 175 360 680 1400
20 120 250 465 950
30 97 200 375 770
40 82 170 320 660
60 66 138 260 530
80 57 118 220 460
100 50 103 195 400
For additional information refer to the National Fuel Gas Code
Handbook.
To check for leaks in gas piping, use a soap and water 3.
solution or other approved method.
Do not use an open ame!!
WARNING
!
Disconnect boiler from gas supply piping system during 4.
any pressure testing of the gas piping. After reconnecting,
leak test gas connection and boiler piping before placing
boiler back into operation.
Natural Gas Propane
Min. Supply Pressure 5" w.c. 11" w.c.
Max. Supply Pressure 14" w.c. 14" w.c.
Manifold Pressure 3.5" w.c. 10.5" w.c.
ELECTRICAL WIRING
See wiring diagrams on the following two
pages for details.
Electrical wiring must conform with the National Electrical
Code, ANSI/NFPA No 70 latest edition when installed in the
United states, the CSA C22.1 Canadian Electrical Code, Part
1, when installed in Canada, and/or the local authority having
jurisdiction.
When an external electrical source is utilized,
the boiler, when installed, must be electrically
grounded in accordance with these require-
ments.
WARNING
!
IMPORTANT: Install a fused disconnect
switch between boiler and electric panel at a
convenient location.
THERMOSTAT INSTALLATION
Thermostat should be installed on an inside wall about 1.
four feet above the oor.
NEVER install a thermostat on an outside wall. 2.
Do not install a thermostat where it will be affected by 3.
drafts, hot or cold pipes, sunlight, lighting xtures, televi-
sions, a replace, or a chimney.
Check thermostat operation by raising and lowering ther- 4.
mostat setting as required to start and stop the burners.
Instructions for the nal adjustment of the thermostat are 5.
packaged with the thermostat (adjusting heating anticipa-
tor, calibration, etc.)

14
WIRING DIAGRAM - 24V STANDING PILOT
VR8200
OR
VR8300

15
WIRING DIAGRAM - INTERMITTENT IGNITION

16
Before lighting any type of pilot burner (standing
or intermittent), make certain the hot water boiler
and system are full of water to minimum pressure
of 12 lbs. per square inch in the system, and also
make certain that the system is vented of air. Set
the operating control of thermostat to a “below”
normal setting. Refer to the following appropriate
lighting instruction.
IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY, A FIRE OR EXPLOSION MAY RESULT,
CAUSING PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.
Before any procedures are attempted on this appliance, it is necessary to determine if the ignition system
is electric or standing pilot. If you are uncertain, contact the manufacturer before proceeding.
LIGHTING INSTRUCTIONS
WARNING
!
WARNING
!
LIGHTING PROCEDURE FOR BOILER WITH
INTERMITTENT PILOT SYSTEM
For Your Safety, Read Before Operating!!
A. This appliance is equipped with an ignition device 1.
which automatically lights the pilot. Do not try to light the
appliance by hand.
B. Before operating, smell all around the appliance area 2.
for gas. Be sure to smell next to the oor because some
gas is heavier than air and will settle on the oor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electrical switches; do not
use any phones in your building.
• Immediately call your gas supplier from a
neighbor’s phone. Follow the gas supplier's
instructions.
• If you cannot reach your gas supplier, call
the re department.
CAUTION
!
C. Use only your hand to push in or turn the gas control
knob. Never use tools. If the knob will not push in or turn
by hand, don’t try to repair it. Call a qualied service
technician. Force or attempted repair may result in a re
or explosion.
D. Do not use this appliance if any part has been under
water. Immediately call a qualied service technician
to inspect the appliance and to replace any part of the
control system and any gas control which has been under
water.
OPERATING INSTRUCTIONS FOR INTERMITTENT
PILOT SYSTEM
STOP! Read the safety information in the User’s Informa- 1.
tion Manual.
Set the thermostat to lowest setting. 2.
Turn off all electric power to the appliance. 3.
This appliance is equipped with an ignition device which 4.
automatically lights the pilot. Do not try to light the pilot by
hand. (Figure #14)
INLET OUTLET
Figure #14
Turn gas control knob clockwise 5. to “OFF.”
Wait (5) minutes to clear out any gas. If you then smell 6.
gas, STOP! Follow “What To Do If You Smell Gas” in the
safety information above. If you don’t smell gas, go on to
the next step.
Turn gas control knob counterclockwise 7. to “ON.”
Turn on all electric power to the appliance. 8.
Set thermostat to desired setting. 9.
If the appliance will not operate, follow the instructions 10.
“ To Turn Off Gas To Appliance ” and call a qualied
service technician or your gas supplier.

17
LIGHTING INSTRUCTIONS
LIGHTING PROCEDURE FOR BOILER WITH
CONTINUOUS PILOT
For Your Safety, Read Before Lighting!!
Read the warning at the beginning of " 1. Lighting Instruc-
tions ."
This appliance has a pilot which must be lighted by hand. 2.
When lighting the pilot, follow these instructions exactly.
Before lighting, smell all around the appliance area for 3.
gas. Be sure to smell next to the oor because some gas
is heavier than air and will settle on the oor. See section
" What To Do If You Smell Gas ."
Use only your hand to push in or turn gas control knob or 4.
reset button. Never use tools. If the knob or reset button
will not push in or turn by hand, don’t try to repair it, call
a qualied service technician. Force or attempted repair
may result in a re or explosion.
Do not use this appliance if any part has been under wa- 5.
ter. Immediately call a qualied service technician to in-
spect the appliance and to replace any part of the control
system and any gas control which has been under water.
LIGHTING INSTRUCTIONS FOR CONTINUOUS PILOT
STOP! 1. Read the safety information at the beginning of
these instructions.
Set the thermostat to the lowest setting.
2.
Turn off all electric power to the appliance. 3.
Remove access panel and burner door. 4.
Turn gas control knob clockwise 5. to "OFF." (Fig-
ures #15 and #16)
INLET
Figure #15
GAS CONTROL KNOB
PRESSURE REGULATOR
ADJUSTMENT BENEATH
COVER SCREW
PILOT FLOW ADJ. SCREW
BENEATH COVER SCREW
OUTLET
PRESSURE
TAP
TAP
PRESSURE
INLET
GAS
INLET
GAS
OUTLET
TH/TR
ON
OFF
PILOT
Figure #16
NOTE: Some gas control knobs cannot be turned from "PILOT"
to "OFF" unless knob is pushed in slightly. DO NOT FORCE.
Wait (5) minutes to clear out any gas. If you then smell 6.
gas, STOP! Follow " What To Do If You Smell Gas ." If
you don't smell gas, go to the next step.
Find pilot. Follow metal tube from gas control. Depending 7.
on the model of the boiler, pilot is either mounted on the
base or on one of the burner tubes.
Turn gas control knob counterclockwise 8. to "PI-
LOT."
Push in gas control knob or reset button if so equipped, 9.
all the way in and hold. Immediately light the pilot with a
match. Continue to hold the gas control knob or reset but-
ton in for about 1 minute after the pilot is lit. Release knob
or button, and it will pop up back up. Pilot should remain
lit. If it goes out, repeat steps 5 through 9.
If knob or button does not pop up when released, stop •
and immediately call a qualied service technician or
your gas supplier.
If the pilot will not stay lit after several tries, turn the gas •
control knob clockwise to "OFF." Call a qualied
service technician or your gas supplier.
Replace burner door.
10.
Turn gas control knob counterclockwise 11. to "ON."
Replace access panel. 12.
Turn on all electric power to the appliance. 13.
Set thermostat to desired setting. 14.
TO TURN OFF GAS TO THE APPLIANCE
Set the thermostat to lowest setting. 1.
2. Turn off all electric power to the appliance if service is 2.
to be performed.
3. Push in gas control knob slightly and turn clockwise 3.
to "OFF." DO NOT FORCE.
4. Call a qualied service technician. 4.

18
NORMAL SEQUENCE OF OPERATION
On a call for heat, the thermostat will actuate,
completing the circuit to the control. The completed
circuit to the control will rst activate the circulator
and damper which will close an end switch inside
the damper. This action will complete the circuit to
the ignition system and ignition will take place.
In the event the boiler water temperature exceeds
the high limit setting on the boiler mounted high
limit control, power will be interrupted between the
control system and the ignition system. The power
will remain off until the boiler water temperature
drops below the high limit setting. The circulator
will continue to operate under this condition until
the thermostat is satised.
In the event the ow of combustion products through
the boiler venting system becomes blocked, the
blocked vent safety switch will shut the main burner
gas off. Similarly, if the boiler ueway becomes
blocked, a ame rollout safety switch will shut the
main burner gas off. (Figure #17) If either of these
conditions occur, DO NOT ATTEMPT TO PLACE
THE BOILER BACK INTO OPERATION. CON-
TACT A CERTIFIED SERVICE AGENCY.
BURNERS
ORIFICES
GAS VALVE
INTEGRAL DRAFT
HOLD DOWN
BOLT
BLOCKED VENT
SAFETY SWITCH
BURNER DOOR
BLOCKED VENT
SAFETY SWITCH
JACKET BASE
PANEL ROLL-OUT SAFETY
SWITCH
MANIFOLD
BASE
HOOD
Figure #17
GENERAL INSTRUCTIONS
Before seasonal start-up, have a certied service agency
check the boiler for soot and scale in the ues, clean the burn-
ers and check the gas input rate to maintain high operating
efciency.
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation.
CAUTION
!
Verify proper operation after service.
The service agency or owner should make certain the system
is lled with water to minimum pressure and open air vents, if
used, to expel any air that may have accumulated in the sys-
tem. Check the entire piping system and, if any leaks appear,
have them repaired.
Circulators need to be checked and maintained. Refer
to the circulator manufacturer's instructions.
The venting system should be inspected at the start of each
heating season. Check the vent pipe from the boiler to the
chimney for signs of deterioration by rust or sagging joints.
Repair if necessary. Remove the vent pipe at the base of the
chimney or ue and using a mirror, check vent for obstruction
and make certain the vent is in good working order.
The boiler ue gas passageways may be inspected by a light
and mirror. Remove the burner door. (
Figure #20 ) Place a
trouble lamp in the ue collector through the draft relief open-
ing. With the mirror positioned above the burners, the ue gas
passageways can be checked for soot or scale.
The following procedure should be followed to clean the ue
gas passageways:
Remove the burners from the combustion chamber by
1.
raising the burners up from the manifold orices and pull-
ing toward the front of the boiler. ( Figure #20 )
Disconnect the vent pipe from the draft hood. 2.
Remove the top jacket panel. 3.
Remove the combination ue collector and draft hood 4.
from the boiler castings by loosening the nuts on the hold
down bolts located on each side of the collector. ( Figure
#17 )
Place a sheet of heavy paper or similar material over the 5.
bottom of the base and brush down the ue passage-
ways. The soot and scale will collect on the paper and is
easily removed with the paper.

19
GENERAL INSTRUCTIONS
With the paper still in place in the base, clean the top of 6.
the boiler castings of the boiler putty or silicone used to
seal between the castings and ue collector. Make certain
that chips are not lodged in the ue passageways.
When the cleaning process is complete, restore the boiler
components to their original position. Use IS-808 GE silicone
(available from a distributor) to seal around the ue collector
and boiler castings.
A visual check of the main burner and pilot ames should be
made at the start of the heating season and again in mid-
season. The main burner ame should have a well dened
inner blue mantel with a lighter blue outer mantel. Check the
burner throats and burner orices for lint or dust obstruction.
(
Figures #19 and #20 )
Figure #19
GAS VALVE
KNOB
ORIFICES
BURNERS
Figure #20
BURNER
DOOR
The pilot ame should envelop ⅜ to ½ inch of the tip of the
pilot thermocouple, ignition/sensing electrode or mercury sen-
sor. ( Figure #21 )
IGNITION ELECTRODE
3/8” TO 1/2”
IN FLAME
Figure #21
To adjust the pilot ame, remove the pilot adjustment cover
screw (Figures #14 - #16 on previous pages) and turn the
inner adjustment screw counterclockwise to increase
or clockwise to decrease pilot ame. Be sure to replace
cover screw after adjustment to prevent possible gas leakage.
The burners and pilot should be checked for signs of corro-
sion, rust or scale buildup. The area around the boiler must
be kept clear and free of combustible materials, gasoline and
other ammable vapors and liquids.
The free ow of combustion and ventilating air to the boiler
and boiler room must not be restricted or blocked.
It is recommended that a qualied service agency be em-
ployed to make an annual inspection of the boiler and heat-
ing system. They are experienced in making the inspections
outlined above, and, in the event repairs or corrections are
necessary, trained technicians can make the proper changes
for safe operation of the boiler.

20
CHECKING GAS INPUT RATE TO BOILER
Gas input to the boiler can be adjusted by removing the
protective cap on the pressure regulator (Figures #14-#16)
and turning the screw clockwise to increase input and
counterclockwise to decrease input. The manifold
pressures are taken at the outlet side of the gas valve.
( Figure #15 and #16 ) To check for proper ow of natural
gas to the boiler, divide the input rate shown on the rating
plate by the heating value of the gas obtained from the
local gas company. This will determine the number of cubic
feet of gas required per hour. With all other gas appliances
off, determine the ow of gas through the meter for two
minutes and multiply by 30 to get the hourly rate. Make
minor adjustments to the gas input as described above.
Burner orices should be changed if the nal manifold
pressure varies more than plus or minus 0.3 inches water
column from the specied pressure.
Primary air adjustment is not necessary, therefore air
shutters are not furnished as standard equipment. Air
shutters can be furnished on request where required by
local codes or conditions.
CHECK SAFETY CONTROL CIRCUIT after burner
adjustments are made for satisfactory operation.
1. Pilot: With main burner operating, turn the pilot
gas adjusting screw clockwise until pilot gas
is turned off. (Figures #14-#16 on previous pages)
Within 90 seconds the main gas control should close,
shutting off the gas to the main burner.
2. High Limit Control (Figure #22): Remove cover and
note temperature setting. Decrease this setting to
minimum and operate boiler. When the boiler water
temperature exceeds the control temperature setting,
the control will open the circuit, closing the automatic
main gas valve.
GAS VALVE
BURNER ACCESS
DOOR
HIGH LIMIT
AND OPERATING
CONTROL
Figure #22