UTICA BOILERS MGB 50 Instruction manual

P/N 37611601, Rev. C [05/2011]
An ISO 9001-2008 Certified Company
MGB SERIES
Cast Iron Gas Fired Boilers
For Forced Hot Water
INSTALLATION, OPERATION &
MAINTENANCE MANUAL
MODEL NUMBERS:
MGB50 MGB75 MGB100
MGB125 MGB150 MGB175
MGB200 MGB250 MGB300
Utica Boilers
2201 Dwyer Avenue •
Utica • New York • 13504 • USA
www.ecrinternational.com

2
IMPORTANT: Read the following instructions
COMPLETELY before installing!!
C.S.A. Certied
For Natural Gas Or Propane
Tested For 100 psi.
ASME
Working Pressure
H
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
Dimensions.........................................................4
Installation Procedure ..........................................5
Ventilation & Combustion Air .................................6
Connecting Supply and Return Piping .....................7
Vent Installation ................................................11
Vent System Modication....................................11
Vent Damper Installation & Instructions................12
Connecting Gas Service......................................13
Electrical Section ...............................................14
Wiring Diagram - 24V Standing Pilot ....................15
Wiring Diagram - Intermittent Ignition .................16
Lighting Instructions ..........................................17
Normal Sequence of Operation ............................19
General Instructions ..........................................19
Checking Gas Input Rate To Boiler .......................21
Replacement Parts ............................................22
InstallatIon, operatIon and MaIntenance Manual
!
DANGER
Indicates a hazardous situation which, if
not avoided, WILL result in death or serious
injury.
!
WARNING
Indicates a hazardous situation which, if
not avoided, could result in death or serious
injury.
!
CAUTION
Indicates a hazardous situation which, if not
avoided, may result in minor or moderate
injury.
NOTICE
Indicates information which should be
followed to ensure proper installation and
operation.
!
WARNING
Keep boiler area clear and free from
combustible materials, gasoline and other
ammable vapors and liquids.
DO NOT obstruct air openings to the boiler
room.
Modication, substitution or elimination
of factory equipped, supplied or specied
components may result in property damage,
personal injury or the loss of life.
TO THE OWNER - Installation and service of
this boiler must be performed by a qualied
installer.
TO THE INSTALLER - Leave all instructions
with the boiler for future reference.
When this product is installed in the
Commonwealth of Massachusetts the
installation must be performed by a Licensed
Plumber or Licensed Gas Fitter.
!
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 methods or materials
may result in serious injury or death due to
re or to asphyxiation from poisonous gases
such as carbon monoxide which is odorless
and invisible.
KEEP THIS MANUAL NEAR BOILER
RETAIN FOR FUTURE REFERENCE

3
Table 1 - Ratings and Capacities
Boiler
No.
(1)
Input
Mbh
(1)
Heating
Capacity Mbh
(2)
**
Net I=B=R
Rating Water
Mbh
No.
of
Burners
(3)
Recommended
Air Cushion
Tank
Water
Content
(Gals.)
High
Altitude
Input
50 50 42 37 115 2.4 45,000
75 75 63 55 215 4.0 67,500
100 100 83 72 230 4.0 90,000
125 125 104 90 3 30 5.6 112,500
150 150 124 108 3 30 5.6 135,000
175 175 143 124 4 30 7.2 157,000
200 200 165 143 4 30 7.2 180,000
250 250 205 178 5 30 8.8 225,000
300 299 243 214 6 60 10.4 270,000
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) Input rating for sea level to 2,000 ft. (610m) above sea level.
United States, over 2000 ft (610m) above sea level. Reduce input rate 4% for every 1000 ft (304m) above sea • level.
Canada, 2000 ft (610m) to 4500 (1350m) above sea level. Reduce input per table.•
Canada, over 4500 ft (1350m) above sea level. Contact Provincial authority having jurisdiction.•
(2) Net I=B=R Water Ratings shown based on piping and pickup allowance of 1.15. Consult manufacturer
before selecting boiler for installations having unusual piping and pickup requirements, such as
intermittent system operation, extensive piping systems, etc.
For forced hot water systems where boiler and all piping within area to be heated, boiler may be selected
on basis of its heating capacity.
(3) Tank sized for non-ferrous baseboard or radiant panel systems. Increase size for cast iron baseboard and
radiation.
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 Valve, Spill Switch, Rollout Switch, Automatic Vent Damper. Not Shown Are:
Wiring Harness, Thermocouple, Non-linting Safety Pilot.
OPTIONAL EQUIPMENT: Intermittent Electric Ignition Pilot System.
ratIngs & data - natural gas & propane gas

4
Table 2 - Dimensions
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" 26
13
⁄
16"13¼" 8" 30¾" 40¾" 8" 1¼"
300 ¾" 30½" 15¼" 9" 30¾" 42¾" 10" 1¼"
* Propane gas inlet, all units, 1/2"
dIMensIons

5
The installation must conform to the requirements of 1.
the authority having jurisdiction or, in the absence
of such requirements, to the National Fuel Gas Code,
ANSI Z223.1/NFPA 54, and/or Natural Gas and Propane
Installation Code, CAN/CSA B149.1.
Where required by the authority having jurisdiction, the 2.
installation must conform to the Standard for Controls
and Safety Devices for Automatically red Boilers,
ANSI/ASME CSD-1.
This boiler series is classied as a Category I. Vent 3.
installation shall be in accordance with "Venting of
Equipment ," of the National Fuel Gas Code, ANSI
Z223.1/NFPA 54, or "Venting Systems and Air Supply
for Appliances," of the Natural Gas and Propane
Installation Code, CAN/CSA B149.1, or applicable
provisions of the local building 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
(dripping, 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 (610mm )at the front and right side for 7.
servicing and cleaning.
When installed in a utility room, the door should be 8.
wide 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 FLOORS
9.
ONLY - For installation on combustible ooring special
base must be used. (See Replacement Parts Section.)
The boiler can not be installed on carpeting. Minimum
clearances to combustible construction are:
TOP ....................................18 IN. (457mm)
FRONT .........................................ALCOVE *
FLUE CONNECTOR ................. 6 IN. (152mm)
REAR ................................... 4 IN. (102mm)
CONTROL SIDE ..................... 9 IN. (229mm)
OTHER SIDE ........................... 3 IN. (76mm)
HOT WATER PIPING .............. 1/2 IN. (13mm)
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"
InstallatIon procedure
!
WARNING
Improper installation, adjustment, alteration,
service or maintenance can cause injury or
property damage.

6
VentIlatIon & coMbustIon aIr
Provide combustion air and ventilation air in accordance
with the section “Air for Combustion and Ventilation,” of the
National Fuel Gas Code, ANSI Z223.1/NFPA 54, or Sections
8.2, 8.3 or 8.4 of Natural Gas and Propane Installation
Code, CAN/CSA B149.1, or applicable provisions of local
building codes.
Provide make-up air where exhaust fans, clothes dryers,
and kitchen ventilation equipment interfere with proper
operation.
National Fuel Gas Code recognizes several methods
of obtaining adequate ventilation and combustion air.
Requirements of the authority having jurisdiction may
override these methods.
Engineered Installations. Must be approved by •
authority having jurisdictions.
Mechanical Air Supply. Provide minimum of 0.35 •
cfm per Mbh for all appliances located within space.
Additional requirements where exhaust fans installed.
Interlock each appliance to mechanical air supply
system to prevent main burner operation when
mechanical air supply system not operating.
All Indoor Air. Calculate minimum volume for all •
appliances in space. Use a different method if
minimum volume not available.
Standard Method. Cannot be used if known air о
inltration rate is less than 0.40 air changes per
hour. See Table 3 for space with boiler only. Use
equation for multiple appliances.
Volume ≥ 50 ft3 x Total Input [Mbh]
Known Air Inltration Rate. See Table 3 for о
space with boiler only. Use equation for multiple
appliances. Do not use an air inltration rate
(ACH) greater than 0.60.
Volume ≥ 21 ft3/ACH x Total Input [Mbh]
Refer to National Fuel Gas Code for opening о
requirements between connection indoor spaces.
All Outdoor Air. Provide permanent opening(s) •
communicating directly or by ducts with outdoors.
Two Permanent Opening Method. Provide opening о
commencing within 12 inches of top and second
opening commencing within 12 inches of bottom
enclosure.
Direct communication with outdoors or 
communicating through vertical ducts. Provide
minimum free area of 1 in2 per 4 Mbh of total
input rating of all appliances in enclosure.
Communicating through horizontal ducts. 
Provide minimum free area of 1 in2 per 2
Mbh of total input rating of all appliances in
enclosure.
One Permanent Opening Method. Provide opening о
commencing within 12 inches of top of enclosure.
Provide minimum clearance of 1 inch on sides
and back and 6 inches on front of boiler (does not
supersede clearance to combustible materials).
Combination Indoor and Outdoor Air. Refer to о
National Fuel Gas Code for additional requirements
for louvers, grilles, screens and air ducts.
Combination Indoor and Outdoor Air. Refer to •
National Fuel Gas Code for application information.
National Gas and Propane Installation Code Requires pro-
viding air supply in accordance with:
Section 8.2 and 8.3 when combination of appliances •
has a total input of up to and including 400 Mbh (120
kW).
Section 8.4 when combination of appliances has total •
input exceeding 400 Mbh (120 kW).
Refer to Natural Gas and Propane Installation Code •
for specic air supply requirements for enclosure
or structure where boiler is installed, including air
supply openings and ducts.
Table 3
Input Mbh Standard
Method Known Air Inltration Rate Method (Air Changes Per Hour)
0.1 0.2 0.3 0.4 0.5 0.6
50 2500 10500 5250 3500 2625 2100 1750
75 3750 15750 7875 5250 3938 3150 2625
100 5000 21000 10500 7000 5250 4200 3500
125 6250 26250 13125 8750 6563 5250 4375
150 7500 31500 15750 10500 7875 6300 5250
175 8750 36750 18375 12250 9188 7350 6125
200 10000 42000 21000 14000 10500 8400 7000
250 12500 52500 26250 17500 13125 10500 8750
300 15000 63000 31500 21000 15750 12600 10500

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.
AIR
SEPARATOR
The boiler, when used in connection with a refrigeration 1.
system, must be installed so the chilled medium is
piped in parallel with the boiler with appropriate valves
to prevent the chilled medium from entering the boiler.
See Figure 5.
The boiler piping system of a hot water boiler 2.
connected to heating coils located in air handling
units where they may be exposed to refrigerated air
circulation must be equipped 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 or 3.
as required by authority having jurisdiction must be
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 psi.
Bypass piping is an option which gives the ability to
6.
adjust 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 base-
board heating systems. Typical installations where
bypass piping is used are as follows:
This method is used to protect boilers from con-A.
densation forming due to low temperature return
water. Generally noticed in large converted grav-
ity systems or other large water volume systems.
Figure 6 & 7.
These methods are used to protect systems using B.
radiant panels and the material they are encased in
from high temperature supply water from the boiler
and protect 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.
connectIng supply and return pIpIng
Figure 5 - Circulators Mounted on System Supply

8
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
7. Installation using circulators and zone valves are
shown in Figures8-11. For further piping information
refer to I=B=R Installation and Piping Guide.
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions.
!
8. Install discharge piping from safety relief valve.
Use ¾" or larger pipe.•
Use pipe suitable for temperatures of 375°F (191°C) •
or greater.
Individual boiler discharge piping shall be independent
•
of other discharge piping.
Size and arrange discharge piping to avoid reducing •
safety relief valve relieving capacity below minimum
relief valve capacity stated on rating plate.
Run pipe as short and straight as possible to location •
protecting user from scalding and properly drain
piping.
Install union, if used, close to safety relief valve outlet.•
Install elbow(s), if used, close to safety relief valve •
outlet and downstream of union (if used).
Terminate pipe with plain end (not threaded).•
connectIng supply and return pIpIng
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
Figure 6 - Bypass Piping Automatic Mixing Valve
Figure 7 - Bypass Piping - Fixed Low Temp Only Automatic Mixing Valve

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
VALVE
PRESSURE
REDUCER VALVE
CHECK VALVE
BALL VALVE AIR SEPARATOR
ZONE VALVE HOSE BIB FLOW CONTROL
VALVE
EXPANSION
TANK
BOILER
DHW
CIRCULATOR
CH CIRCULATOR
PRIORITY ZONE
CIRCULATOR
EXPANSION
TANK
WATER INLET
FLOW CONTROL
VAVLE SHUT-OFF
VALVE
PRESSURE
REDUCER VALVE
CHECK VALVE
BALL VALVE
AIR SEPARATOR
ZONE VALVE
HOSE BIB
connectIng supply and return pIpIng
Figure 8 - Single Zone System With DHW Priority
Figure 9 - Multi Zone System With Circulators And DHW Priority

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
VALVE
PRESSURE
REDUCER VALVE
CHECK VALVE
EXPANSION
TANK
AIR SEPARATOR
ZONE VALVE HOSE BIB
FLOW CONTROL
VALVE
connectIng supply and return pIpIng
Figure 10 - Multi Zone System With Zone Valves And DHW Priority (With Circulator)
Figure 11 - Multi Zone System With Zone Valves And Dhw Priority (With Zone Valve)

11
When an existing boiler is removed from a common
venting system, the system is likely to be too large for the
proper venting of the appliances sill connected to it. If
this situation occurs, the following test procedure must be
followed:
The vent pipe must slope upward from the boiler not 1.
less then ¼ inch for every 1 foot (21mm/m) to vent
terminal.
Horizontal portions of the venting system shall be 2.
supported 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 I. Vent 3.
installation shall be in accordance with "Venting of
Equipment," of the National Fuel Gas Code, ANSI
Z223.1/NFPA 54, or "Venting Systems and Air Supply
for Appliances," of the Natural Gas and Propane
Installation Code, CAN/CSA B149.1, or applicable
provisions of the local building codes.
Inspect chimney to make certain it is constructed 4.
according 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
ANSI Z223.13 or CAN/CSA B149.1. 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.
Vent InstallatIon
!
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 methods or materials
may result in serious injury or death due to
re or to asphyxiation from poisonous 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.
Vent systeM ModIfIcatIon
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 1.
system.
Visually inspect the venting system for proper size and 2.
horizontal pitch and determine there is no blockage or
restriction, leakage, corrosion and other deciencies
which could cause an unsafe condition.
Insofar as is practical, close all building doors and 3.
windows 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 6.
remaining connected to a common venting system
properly vents when tested as outlined above, return
doors, windows, 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.
should be corrected so the installation conforms with
the National Fuel gas Code, ANSI Z223.1/NFPA 54,
and/or the Natural Gas and Propane Installation Code,
CAN/CSA B149.1. When re-sizing any portion of the
common venting system, the common venting system
should be re-sized to approach the minimum size
determined using the appropriate tables in Chapter 13
of the National Fuel Gas Code, ANSI Z223.1/NFPA 54,
and/or the Natural Gas and Propane Installation Code,
CAN/CSA B149.1.

12
DAMPER INSTALLATION
NOTE: Refer to Figure 11 for steps 1-6.
Place Vent Damper on or as close to vent outlet of 1.
boiler as possible. Figure 13.
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 6.
accordance with Figure 12.
DAMPER INSTRUCTIONS
Verify only boiler is serviced by Vent Damper. 1. Figure
13.
Clearance of not less than 6 inches (152mm) between 2.
Vent 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 3.
appliance 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.
Vent daMper InstallatIon & InstructIons
Figure 12 - Damper Motor Wiring Figure 13 - Vent Damper Placement

13
General
Use piping materials and joining methods acceptable •
to authority having jurisdiction. In absence of such
requirements:
USA - National Fuel gas Code, ANSI Z223.1/NFPA 54•
Canada - Natural Gas and Propane Installation Code, •
CAN/CSA B149.1
Size and install gas piping system to provide sufcient •
gas supply to meet maximum input at not less than
minimum supply pressure. See Table 5.
Support piping with hooks straps, bands, brackets, •
hangers, or building structure components to prevent or
dampen excessive vibrations and prevent strain on gas
connection. Boiler will not support piping weight.
Use thread (joint) compound (pipe dope) suitable for •
liqueed petroleum gas.
Install eld sourced manual main shutoff valve, ground •
joint union, and sediment trap upstream of gas valve.
See Figure 14.
Table 5 Natural Gas Propane
Min. Supply Pressure 5" w.c. 11" w.c.
Max. Supply Pressure 13.5" w.c. 13.5" w.c.
Manifold Pressure 3.5" w.c. 10.5" w.c.
!
DANGER
Fire Hazard. Do not use matches, candles,
open ames, or other methods providing
ignition source. Failure to comply will result in
death or serious injury.
Leak Check Gas Piping
Pressure test boiler and gas connection before placing
boiler in operation.
Pressure test over 1/2 psig (3.5 kPa). Disconnect •
boiler and its individual gas shutoff valve from gas
supply system.
Pressure test at 1/2 psig (3.5 kPa) or less. Isolate •
boiler from gas supply system by closing manual gas
shutoff valve.
Locate leakage using gas detector, noncorrosive •
detection uid, or other leak detection method
acceptable to authority having jurisdiction. Do not
use matches, candles, open ames, or other methods
providing ignition source.
Correct leaks immediately and retest. •
connectIng gas serVIce
MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS/HOUR
(Gas Pressure = 0.5 psig or less, Pressure Drop = 5 in. w/c)
Table 4
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.
Figure 14 - Gas Piping
!
CAUTION
WHAT TO DO IF YOU SMELL GAS
Do not try to light any appliance.•
Do not touch any electrical switch; do not •
use any phones in your building.
Immediately call your gas supplier from
•
a neighbor’s phone. Follow gas supplier’s
instructions.
If you cannot reach your gas supplier, call
•
the re department.

14
electrIcal sectIon
ELECTRICAL WIRING
See wiring diagrams on the following two pages for
details.
Electrically bond boiler to ground in accordance with
requirements of authority having jurisdiction. Refer to:
USA- National Electrical Code, ANSI/NFPA 70.•
Canada - Canadian Electrical Code, Part I, CSA C22.1: •
Safety Standard for Electrical Installations.
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 3.
by drafts, hot or cold pipes, sunlight, lighting xtures,
televisions, a replace, or a chimney.
Check thermostat operation by raising and lowering 4.
thermostat setting as required to start and stop the
burners.
Instructions for the nal adjustment of the thermostat 5.
are packaged with the thermostat (adjusting heating
anticipator, calibration, etc.)
!
WARNING
Electrical shock hazard. Turn OFF electrical
power supply at service panel before making
electrical connections. Failure to do so could
result in death or serious injury.

15
VR8200
OR
VR8300
WIrIng dIagraM - 24V standIng pIlot

16
WIrIng dIagraM - InterMIttent IgnItIon

17
LIGHTING PROCEDURE FOR BOILER WITH
INTERMITTENT PILOT SYSTEM
For Your Safety, Read Before Operating!!
This appliance is equipped with an ignition device which A.
automatically lights the pilot. Do not try to light the
appliance by hand.
Before operating, smell all around the appliance area B.
for gas. Be sure to smell next to the oor because
some gas is heavier than air and will settle on the oor.
!
CAUTION
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 re department.
Use only your hand to push in or turn the gas control C. 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.
Do not use this appliance if any part has been under
D.
water. Immediately call a qualied service technician
to inspect appliance and to replace any part of control
system and any gas control which has been under
water.
OPERATING INSTRUCTIONS FOR INTERMITTENT PI-
LOT SYSTEM
STOP! Read the safety information to the left. 1.
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 15 - Intermittent Pilot
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 to the left. 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 ” on next page, and
call a qualied service technician or your gas supplier.
lIghtIng InstructIons
!
WARNING
If you do not follow these instructions exactly,
a re or explosion may result, causing
property damage, personal injury or loss of
life.
Before any procedures are attempted on this
appliance, determine if ignition system is
electric or standing pilot. If you are uncertain,
contact manufacturer before proceeding.
!
WARNING
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 psi in the system,
and also verify system is vented of air. Set
operating control of thermostat to “below”
normal setting. Refer to following appropriate
lighting instruction.

18
LIGHTING PROCEDURE FOR BOILER WITH
CONTINUOUS PILOT
For Your Safety, Read Before Lighting!!
Read the warning at the beginning of "
1. Lighting
Instructions ."
This appliance has a pilot which must be lighted by 2.
hand. 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 " on previous
page
Use only your hand to push in or turn gas control knob 4.
or 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
5.
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.
LIGHTING INSTRUCTIONS FOR CONTINUOUS PILOT
STOP! 1. Read the safety information above.
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."
(Figures 16 and 17)
Figure 16 - Gas Control Knob
INLET
Figure 17 - Continuous Pilot
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 "
on previous page. If you don't smell gas, go to the
next step.
Find pilot. Follow metal tube from gas control. Depend- 7.
ing 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 button 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 techni-
cian 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.
Turn off all electric power to the appliance if service is 2.
to be performed.
Push in gas control knob slightly and turn clockwise 3.
to "OFF." DO NOT FORCE.
Call a qualied service technician. 4.
lIghtIng InstructIons

19
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
ue-way becomes blocked, a ame rollout safety
switch will shut the main burner gas off. Figure
18. If either of these conditions occur, DO
NOT ATTEMPT TO PLACE THE BOILER BACK
INTO OPERATION. CONTACT A CERTIFIED
SERVICE AGENCY.
BURNERS
ORIFICES
GAS VALVE
INTEGRALDRAFT
HOLD DOWN
BOLT
BLOCKED VENT
SAFETY SWITCH
BURNER DOOR
BLOCKED VENT
SAFETY SWITCH
JACKET BASE
PANEL ROLL-OUT SAFETY
SWITCH
MANIFOLD
BASE
HOOD
Before seasonal start-up, have a certied service agency
check the boiler for soot and scale in the ues, clean the
burners and check the gas input rate to maintain high
operating efciency.
!
CAUTION
Label all wires prior to disconnection when
servicing controls. Wiring errors can cause
improper and dangerous operation.
Verify proper operation after servicing
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 system. 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 21 . Place
a trouble lamp in the ue collector through the draft relief
opening. 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
pulling toward the front of the boiler. Figure 21 .
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 5.
the bottom of the base and brush down the ue
passageways. The soot and scale will collect on the
paper and is easily removed with the paper.
With the paper still in place in the base, clean the top 6.
of 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.
norMal sequence of operatIon
general InstructIons
Figure 18 - Blocked Vent Safety Switch, Roll-out
Safety Switch

20
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 20 and 21 .
Figure 20 - Gas Burner Orices
The pilot ame should envelop ⅜ to ½ inch of the tip of the
pilot thermocouple, ignition/sensing electrode or mercury
sensor.
Figure 21.
To adjust the pilot ame, remove the pilot adjustment
cover screw 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. Figures 15 -
17 on previous pages.
The burners and pilot should be checked for signs of
corrosion, 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.
Inspect eld sourced low water cutoffs annually, or as
recommended by low water cutoff manufacturer. Flush
oat type low water cutoffs per manufacturer's instructions.
It is recommended that a qualied service agency be
employed to make an annual inspection of the boiler and
heating 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.
general InstructIons
IGNITION ELECTRODE
3/8” TO 1/2”
IN FLAME
Figure 19 - Gas Burner Flame
Figure 21 - Gas Burner Pilot