UTICA BOILERS UB90-50 Instruction manual

P/N# 240010135 Rev. C [05/2013]
An ISO 9001-2008 Certified Company
Models
UB90-50
UB90-75
UB90-100
Manufacturedby:
ECRInternational,Inc.
2201 Dwyer Avenue, Utica NY 13504-4729
web site: www.ecrinternational.com
UB90-50/75/100 Series 4
GAS-FIRED, DIRECT VENT,
CONDENSING,
HOT WATER BOILER
INSTALLATION, OPERATION &
MAINTENANCE MANUAL

2
DIMENSIONS
2
Figure 1 - Boiler Dimensions
NOTICE
Draft inducer (blower) may be
rotated 90° or 180° to orient
vent connection towards right
side or rear.

3
INTRODUCTION
Introduction
• This appliance is a gas-fired direct vent hot water boiler
with cast aluminum boiler sections.
• The heating system water absorbs large amounts of
heat from the cast aluminum heat exchanger, cooling
flue gases and causing condensation.
• Sealed combustion, premix gas burner, and low flame
temperature means reduced CO and NOx emissions,
which contribute to cleaner and healthier environment.
• This appliance takes its combustion air directly from
outdoors (sealed combustion) and does not compete
with building occupants for fresh air.
• Sealed combustion (also known as “direct vent”)
is safest and best way to obtain plenty of clean
combustion air.
Dimensions.................................................................................................................... 2
Introduction................................................................................................................... 3
Important Safety Information...........................................................................................4
Boiler Ratings & Capacities ..............................................................................................5
Boilers For Use At High Altitude - United States Installations ................................................ 6
Before Installing The Boiler .............................................................................................. 8
Boiler Installation ...........................................................................................................9
Near Boiler Piping ......................................................................................................... 11
Combustion Air And Vent Pipe ........................................................................................ 22
Gas Supply Piping......................................................................................................... 28
Electrical Wiring ........................................................................................................... 30
Controls And Accessories ............................................................................................... 34
Start Up ...................................................................................................................... 36
Operating Instructions................................................................................................... 37
Detailed Sequence Of Operation ..................................................................................... 38
Verification Procedure And Adjustment ............................................................................ 42
Differential Air Pressure Switch Check - All Models ............................................................ 45
Negative Pressure Switch Check ..................................................................................... 46
Maintenance And Cleaning ............................................................................................. 47
Troubleshooting............................................................................................................ 49
Troubleshooting - High Limit Control And LWCO ............................................................... 50
Troubleshooting -Hydrostat High Limit Control And LWCO .................................................. 51
Appendix A - Water Quality, Water Treatment And Freeze Protection ........................58
Installation And Check-Out Certificate ............................................................................. 62
• Induced draft fan draws in outside combustion
air, takes cooler flue gases from boiler unit and
provides positive removal of flue gases from the
building through readily available PVC, CPVC and PP
(Polypropylene) pipes.
• These low pressure gas-fired hot water boilers are
design certified by CSA International for use with
natural gas and propane gas.
• Boilers are constructed and hydrostatically tested for
maximum working pressure of 50 psig (pounds per
square inch gage) in accordance with A.S.M.E. Boiler
and Pressure Vessel Code Section IV Standards for
heating boilers.

4
Installation shall conform to requirements of
authority having jurisdiction or in absence of such
requirements:
• United States
• National Fuel Gas Code, ANSI Z223.1/NFPA 54
.
• National Electrical Code, NFPA 70.
• Canada
• Natural Gas and Propane Installation Code, CAN/CSA
B149.1.
• Canadian Electrical Code, Part I, Safety Standard for
Electrical Installations, CSA C22.1
Where required by authority having jurisdiction,
installation shall conform to Standard for Controls
and Safety Devices for Automatically Fired Boilers,
ANSI/ASME CSD-1.
Additional manual reset low water cutoff and/or manual
reset high limit may be required.
Requirements for Commonwealth of
Massachusetts:
Boiler installation must conform to Commonwealth of
Massachusetts code 248 CMR which includes but is not
limited to:
• Installation by licensed plumber or gas fitter.
Installers - Follow local regulations with respect to
installation of CO (Carbon Monoxide) Detectors. Follow
maintenance recommendations“Maintenance And Cleaning”
on page 47.
NOTICE
Used to address practices not related to personal
injury.
CAUTION
Indicates a hazardous situation which, if not avoided,
could result in minor or moderate injury.
!
!
WARNING
Indicates a hazardous situation which, if not avoided,
could result in death or serious injury.
!
DANGER
Indicates a hazardous situation which, if not avoided,
WILL result in death or serious injury
!
This is the safety alert symbol. Symbol alerts you to
This is the safety alert symbol. Symbol alerts you to
potential personal injury hazards. Obey all safety messages
potential personal injury hazards. Obey all safety messages
following this symbol to avoid possible injury or death.
following this symbol to avoid possible injury or death.
Become familiar with symbols identifying
Become familiar with symbols identifying
potential hazards.
potential hazards.
General
Boiler installation shall be completed by qualified agency.
See glossary for additional information.
WARNING
Fire, explosion, asphyxiation and electrical shock
hazard. Improper installation could result in death
or serious injury. Read this manual and understand
all requirements before beginning installation.
!
IMPORTANT SAFETY INFORMATION
Keep this manual near boiler
Retain for future reference

5
Table 1 - SEA LEVEL RATINGS – NATURAL AND PROPANE GASES
Model Input
*(MBH) ++ Heating Capacity
*(MBH) Net AHRI Rating *(MBH) Shipping Weight (lbs.) AFUE
90-50 50 45 39 220 90.0
90-75 75 68 59 220 90.0
90-100 100 90 78 220 90.0
* 1 MBH = 1,000 Btuh Btuh = British Thermal Units Per Hour
BOILER RATINGS & CAPACITIES
++ AFUE (Annual Fuel Utilization Efficiency) and Heating Capacity is based on the D.O.E. (Department of Energy) test
procedure.
Heating Capacity indicates the amount of heat available after subtracting losses up the stack. Most of this heat is available
to heat water. A small portion is heat from jacket and surfaces of the boiler, and it is assumed that this heat stays in the
structure.
Net AHRI rating represents portion of remaining heat that can be applied to heat radiation or terminal units (i.e. finned
tube baseboard, cast iron radiators, radiant floor, etc.). The difference between Heating Capacity and Net AHRI Rating,
called piping and pickup allowance, establishes reserve for heating volume of water in system and offsetting heat losses
from piping.
Net AHRI ratings shown are based on piping and pickup factor of 1.15 in accordance with AHRI Standard as published
by Hydronics Institute. Net AHRI rating of boiler selected should be greater than or equal to the calculated peak heating
load (heat loss) for building or area(s) served by boiler and associated hot water heating systems. Consult manufacturer
before selecting a boiler for installations having unusual piping and pickup requirements.
Boilers for use at high altitude
Canada - Boilers are factory equipped for operation at altitudes ranging from 0-4,500 feet above sea level. Contact
Provincial authority having jurisdiction for installations above 4,500 feet (1,350m) above sea level.
United States - See “Boilers For Use At High Altitude” on page 6.

6
Table 2 - NATURAL GAS
MODEL 90-50
Stock Factory Btu Value of Natural Gas++
Settings 750 850 950 1000 1050
Altitude in Ft. 0-5,000 5,000-10,000
Normal Input (MBH) 50 – – – – –
Combustion Setting (CO
2
)8.7 - 9.7% (CO <100 ppm)
Orifice 43331094 43331094
MODEL 90-75
Stock Factory Btu Value of Natural Gas++
Settings 750 850 950 1000 1050
Altitude in Ft. 0-5,000 5,000-10,000
Normal Input (MBH) 75 – – – – –
Combustion Setting (CO
2
)8.7 - 9.7% (CO <100 ppm)
Orifice 43331092 43331092
MODEL 90-100 /
Stock Factory Btu Value of Natural Gas++
Settings 750 850 950 1000 1050
Altitude in Ft. 0-5,000 5,000-10,000
Normal Input (MBH) 100 – – – – –
Combustion Setting (CO
2
)8.7 - 9.7% (CO <100 ppm)
Orifice 43331090 43331090
++Contact local gas utility or distributor for Btu value of gas.
BOILERS FOR USE AT HIGH ALTITUDE - UNITED STATES INSTALLATIONS
• Boilers (with exception of 90-75 propane (LP) product)
are factory equipped for operation at altitudes ranging
from 0-10,000 feet above sea level.
• No changes to factory settings are required for
installations from 0-5,000 feet above sea level.
• For altitudes from 5,000-10,000 feet above sea level
gas manifold pressure needs to be adjusted based upon
calorific (Btu) value of supply gas (contact local gas
utility or distributor for this value).
• For specific settings refer to Table 2 for natural gas
applications and
Table 3, Page 7 for propane (LP) gas
applications.
• Instructions on how to adjust gas manifold pressure
settings see
Figure 25 and Figure 26, Page 44 .
Note 90-75 propane (LP) applications for 5,000 - 10,000
feet above sea level require orifice change as well as gas
manifold pressure adjustment based upon calorific (Btu)
value of supply gas.
Refer to
Table 2 and Table 3 for high altitude orifice
part numbers. For replacing an orifice refer to specific
instructions included with conversion kit.

7
Table 3 - PROPANE GAS
MODEL 90-50
Stock Factory Btu Value of Propane Gas++
Settings 2300 2350 2400 2450 2500
Altitude in Ft. 0-5,000 5,000-10,000
Normal Input (MBH) 50
–– – – –
Combustion Setting (CO
2
)
10.0 -11.1% (CO < 100 ppm)
Orifice 43331095 43331095
MODEL 90-75*
Stock Factory Btu Value of Propane Gas++
Settings 2300 2350 2400 2450 2500
Altitude in Ft. 0-5,000 5,000-10,000
Normal Input (MBH) 75
–– – – –
Combustion Setting (CO
2
)
10.0 -11.1% (CO < 100 ppm)
Orifice 43331093
43331096*
* For model 90-75 Propane units only at altitudes above 5,000 ft., install 90-75 High Altitude Orifice Kit #550002629 For all other
altitudes use sea level orifice. MODEL 90-100 **
Stock Factory Btu Value of Propane Gas++
Settings 2300 2350 2400 2450 2500
Altitude in Ft. 0-5,000 5,000-10,000
Normal Input (MBH) 100
–– – – –
Combustion Setting (CO
2
)
10.0 -11.1% (CO < 100 ppm)
Orifice 43331091
43331091
++Contact local gas utility or distributor for Btu value of gas.
BOILERS FOR USE AT HIGH ALTITUDE - UNITED STATES INSTALLATIONS
Model 90-75 propane (LP) units only at altitudes
above 5,000 ft., install 90-75 High Altitude Orifice Kit
#550002629*.
For all other altitudes use sea level orifice

8
Boiler Sizing
Check to be sure you have selected boiler with proper
capacity before starting installation. AHRI Rating of boiler
selected should be greater than or equal to calculated
peak heating load (heat loss) for building or area(s) served
by boiler and associated hot water heating systems. See
Table 1, Page 5.
Heat loss calculations should be based on approved
industry methods.
Boiler Location Considerations
Before selecting boiler location consider following.
• Supplied with correct type of gas (natural gas or
propane).
• Connected to suitable combustion air intake piping
system to supply correct amounts of fresh (outdoor)
air for combustion, refer to “Combustion Air and Vent
Pipe” on page 22 for details.
• Connected to suitable venting system to remove
hazardous products of gas combustion, refer to
“Combustion Air and Vent Pipe” on page 22 for details.
• Connected to suitable hot water heating system.
• Supplied with suitable electrical supply for all boiler
motors and controls.
• Connected to properly located thermostat or operating
control. Not included with boiler.
• Placed on level surface.
• Condensate drain line must be pitched down to floor
drain or external condensate pump with reservoir at ¼”
per foot (wood frame or blocks may be used to raise
boiler).
1. Boiler is equipped for residential installations. If used
for commercial applications, any additional code
requirements must be adhered to for installation.
This may require additional controls including but not
limited to an additional low water cut off, a manual
reset high temperature limit, and wiring and/or piping
modifications.
2. Before servicing boiler - allow boiler to cool. Shut off
electricity and gas supply connected to boiler prior to
servicing.
3. Inspect gas line for leaks.
4. Verify gas input rate is correct. Over firing may result
in early failure of boiler sections. This may cause
dangerous operation. Under firing may result in too
much air for pre-mix burner causing poor or loss of
combustion.
5. Never vent products of combustion from this boiler to
enclosed space. Always vent to outdoors. Never vent to
another room or to inside building.
6. Be sure there is adequate outdoor air supply to boiler
for complete combustion.
7. Follow regular service and maintenance schedule for
efficient and safe operation.
8. Keep boiler area clean of debris and free of combustible
and flammable materials.
9. Proper through wall or through roof combustion venting
shall be in accordance with materials and methods
described in this manual. Installation must comply with
local codes.
10. Boiler and related hot water heating systems are not do
it yourself items they must be installed and serviced by
qualified professionals.
BEFORE INSTALLING THE BOILER
Minimum Clearances To Combustible Construction
8”
Boiler
Rear
Front
Control Side
Opposite Side
1”
(26MM) 11”
(280MM)
1”
(26MM)
1”
(26MM)

9
Table 4 - Required Clearances
Unit Combustible
Clearance
Accessibility,
Cleaning, and
Servicing
Top 1” (26mm) 8” (204mm)
Left Side 1 “ (26mm) -
Right Side 11” (280mm) -
Base 1” (26mm) -
Front 1” (26mm) 24” (610mm)
Back 1” (26mm) -
Intake/Vent Piping 0 (0) -
All distances measured from the cabinet of the boiler.
Locating The Boiler
1. Place crated boiler as close to selected location as
possible and un-crate boiler. Boiler may be moved into
position with appliance dolly or 2 wheel hand truck.
Insert dolly or hand truck under left hand side of
boiler. It is possible to slide boiler for short distance on
smooth floor or surface.
2. Select level location central to piping systems served
and as close to vent and air intake terminals as
possible.
3. Accessibility clearances, if more stringent (i.e. larger
clearances) than required fire protection clearances,
must be used for boiler installation. Accessibility
clearances may be achieved with the use of removable
walls or partitions.
4. Boiler is approved for installation in closets and on
combustible floors. This boiler shall NOT be installed on
carpeting.
5. Clearances shown in Table 4 indicate required
clearances. Maintain minimum 1” clearance between
combustible construction and each of left, top and
back surfaces of the boiler. Minimum 11” clearance is
required on right side, to allow room for induced draft
blower. Allow 24” at front and 8” at top for servicing.
No clearances are required to venting or combustion air
intake piping.
6. Install equipment in location which facilitates operation
of venting and combustion air intake piping systems
as described in this manual. Draft inducer (blower)
may be rotated 90° or 180° to orient vent connections
towards right side or rear. Remove blower mounting
screws. Orient blower and install mounting screws. Do
not overtighten screws.
7. Advise owner to keep venting and combustion air
intake passages free of obstructions. Both venting
and combustion air intake piping systems connected
to outdoors must permit flow through piping systems
without restrictions for boiler operation.
8. Install boiler such that the automatic gas ignition
system components are protected from water
(dripping, spraying, rain, etc.) during operation and
service (circulator replacement, condensate trap,
control replacement, etc.).
9. Keep boiler area clean of debris and free of flammable
and combustible materials, vapors and liquids.
10. Locate boiler where minimum possible room
temperature where boiler is installed, assuming boiler
is not in operation and therefore contributes no heat
to space, is always at or above 32°F (0°C) to prevent
freezing of liquid condensate.
Combustion Air And Vent Pipe Requirements
This boiler requires a dedicated direct vent system. In a
direct vent system, all air for combustion is taken directly
from outside atmosphere, and all flue products are
discharged to outside atmosphere.
Terminate combustion air and vent pipe connections in
same atmospheric pressure zone, through roof or sidewall
(roof termination preferred). See Figure 12 thru Figure 14,
pages 24 and 25 for required clearances.
WARNING
Solvent cements are combustible. Keep away from
heat, sparks, and open flame. Use only in well
ventilated areas. Avoid breathing in vapor or allowing
contact with skin or eyes. Failure to follow these
instructions could result in fire, serious injury, or death.
!
• Combustion air must be clean outdoor air. Combustion
air must not be taken from inside structure because
that air frequently is contaminated by halogens, which
include fluorides, chlorides, phosphates, bromides
and iodides. These elements are found in aerosols,
detergents, bleaches, cleaning solvents, salts, air
fresheners, paints, adhesives and other household
products.
• Locate combustion air inlet as far away as possible
from swimming pool and swimming pool pump house.
• All combustion air and vent pipes must be airtight and
watertight. Combustion air and vent piping must also
terminate as shown in “Combustion Air and Vent
Pipe” section.
• Vent connections serving appliances vented by
natural draft shall not be connected into any portion
of mechanical draft systems operating under positive
pressure.
BOILER INSTALLATION

10
Condensate Drain Requirements
• Pitch condensate drain line down to floor drain at
minimum of ¼” per foot. External condensate pump
(not furnished) may be used if floor drain is not
available. Installation shall conform to requirements
of authority having jurisdiction, check local codes for
requirements.
• Condensate pump must be designed for flue gas
condensate application.
• Condensate trap provided with boiler, an additional trap
is not required and should not be used.
• Wood frame or blocks may be used to raise boiler
to maintain drain pitch or to be above external
condensate pump reservoir.
Foundation Requirements
• Install boiler on level surface.
WARNING
Fire hazard. Do not install boiler on carpeting.
Failure to follow these instructions could result in
death or serious injury.
!
• Boiler is NOT to be installed on carpeting.
• If boiler is not level condensate drain lines will not
function properly. Adjustable feet are located on the
boiler to make up for minor surface irregularities or tilt.
• Wood frame or blocks may be used to raise boiler
to maintain drain pitch or to be above external
condensate pump reservoir.
Removal of Existing Boiler From Common Vent
System
When an existing boiler 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 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.
1. Seal any unused openings in the common venting
system.
2. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage, or
restrictions, leakage, corrosion and other deficiencies
which could cause an unsafe condition.
BOILER INSTALLATION
3. In-so-far as is practical, close all building doors and
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 dryer and any appliance not connected
to the common venting system. Turn on any exhaust
fans, such as range hoods and bathroom exhaust, so
they will operate at maximum speed. Do not operate a
summer exhaust fan. Close fire dampers.
4. Place in operation the appliance being inspected.
Follow the lighting instructions. Adjust thermostat so
appliances will operate continuously.
5. Test for spillage at the draft hood relief opening after 5
minutes of main burner operation. Use the flame of a
match or candle, or the smoke from a cigarette, cigar
or pipe.
6. 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, fire place dampers,
and any other gas-burning appliance to their previous
condition of use.
7. Any improper operation of the common venting system
should be corrected so the installation conforms with
the National Fuel Code, NFPA-54/ANSI -Z223.1 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 as
determined using the appropriate of the National Fuel
Gas Code, NFPA-54/ANSI- Z223.1 and/or the Natural
Gas and Propane Installation Code, CAN/CSA B149.1.

11
Near Boiler Piping
• When boiler installation is for new heating system,
install all of radiation units (panels, radiators,
baseboard, or tubing) and supply and return mains.
• After all heating system piping and components
have been installed, make final connection of system
piping to boiler. Hot water boiler installed above
radiation level, or as required by the Authority having
jurisdiction, must be equipped with low water cut off
device.
• Periodic inspection is necessary for flushing of float
type devices, per low water cut off manufacturers
specific instructions.
Clean System First
Before connecting boiler to heating system, clean and flush
system thoroughly. Verify system is free of sediment, flux
and any residual boiler water additives.
Systems having antifreeze not recommended must be
completely flushed to insure no old antifreeze remains.
In older systems obviously discolored, murky or dirty
water; or pH reading outside acceptable range (between
7.0 and 8.0) are indications the system should be cleaned
or treated. Thoroughly flush system with clean water to
remove any sediment or contaminants. Sludge and iron
oxide deposits can cause rapid breakdown of inhibitors.
Flushing with clean water. If chemical cleaners are used,
use only those recommended for use with aluminum
boilers. Follow chemical cleaner manufacturer’s instructions
completely. DO NOT mix different manufacturer’s
products.
NEAR BOILER PIPING
Supply And Return Lines
• Boiler is set up to receive 1¼” NPT supply and return
piping from top access.
• Boiler may be piped from left side by turning supply
elbow.
• Install furnished dielectric unions at boiler supply and
return lines prior to making system piping connections
• Do not install copper supply and return piping directly
into aluminum boiler section casings due to galvanic
corrosion between dissimilar metals.
• Must use provided dielectric unions between copper
system piping and boiler to make final connection to
boiler.
• Circulator pump can be installed at installer preferred
location.

12
NEAR BOILER PIPING
Figure 2 - Single Zone Boiler Piping
SAFETY RELIEF VALVE - SEE PAGE 18
FOR REQUIREMENTS

13
Figure 3 - Two Zone Boiler Piping With Zone Valves
NEAR BOILER PIPING
Multi-Zone Systems
Multi-zone systems with two zones are typically piped as
shown in Figures 3 or 4. Multi-zone systems with more than
two zones are likely to have small zones with very low heat
and flow requirements compared to full heating capacity of
the boiler. This can result in very low flow in the boiler if
only one small zone is calling for heat.
Primary Secondary Piping is recommended for multi-zone
systems with more than two zones to insure proper water
flow through the boiler at all times. See Figures 5, 6 and 7
for typical primary secondary piping configurations.
SAFETY RELIEF VALVE - SEE PAGE 18
FOR REQUIREMENTS

14
Figure 4 - Two Zone Boiler Piping With Circulators
NEAR BOILER PIPING
SAFETY RELIEF VALVE - SEE PAGE 18
FOR REQUIREMENTS

15
NEAR BOILER PIPING
Figure 5 - Primary/Secondary Piping With Circulators And Domestic Hot Water

16
NEAR BOILER PIPING
Figure 6 - Piping Primary/Secondary Multi Zone System Piping With Zone Valves And
Domestic Hot Water (With Zone Valve)

17
NEAR BOILER PIPING
Figure 7 - Piping Primary/Secondary Piping With Zone Valves And Domestic Hot Water
(With Circulator)

18
Safety Relief Valve
Installation of safety relief valve shall conform to ANSI/
ASME Boiler and Pressure Vessel Code, Section IV.
• Install furnished safety relief valve using 3/4” x 4½”
pipe provided with boiler. See Figure 8.
• Install safety relief valve with spindle in vertical
position.
• Do not install shutoff valve between boiler and safety
relief valve.
• Install discharge piping from safety relief valve. See
Figure 8.
• 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).
Expansion Tank And Make-Up Water
Determine required system fill pressure, system design
temperature, and system water content.
• Boiler contains 2.6 gallons (U.S.). Size expansion tank
accordingly. Consult expansion tank manufacturer for
proper sizing information.
• Connect properly sized expansion tank (not furnished).
Diaphragm type expansion tank see Figure 9, Page 19.
See Figure 10, Page 20 for conventional closed type
expansion tanks.
• For diaphragm type expansion tanks, adjust tank
air pressure to match system fill pressure. Install
furnished air vents shown for diaphragm type
expansion tank system only.
• Install make-up water connections as shown per local
codes.
• If pressure reducing valve is used, adjust to match
system fill pressure.
• Verify clean water supply is available. When water
supply is from well or pump, install sand strainer at
pump
Figure 8 - Relief Valve Boiler Piping
NEAR BOILER PIPING
RELIEF VALVE
DISCHARGE
LINE
Check local
codes for
maximum
distance
from floor
or allowable
safe point of
discharge.
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions.
!

19
Figure 9 - Diaphragm Type Expansion Tank Piping
NEAR BOILER PIPING
SAFETY RELIEF VALVE - SEE PAGE 18
FOR REQUIREMENTS

20
Figure 10 - Conventional (Closed Type) Expansion Tank Piping
NEAR BOILER PIPING
SAFETY RELIEF VALVE
SEE PAGE 18 FOR
REQUIREMENTS