ECR International UTICA HEATING UH15B-K Instruction manual

Models
UH15B-060K
UH15B-095K
UH15B-120K
UH15B-150K
UH15B-175K
UH15B-205K
UH15B-235K
UH15B-K
With Hydrolevel 4200 Control
Cast Iron Gas Fired Boilers
For Forced Hot Water
INSTALLATION, OPER ATION &
MAINTENANCE MANUAL
Tested For 50 psi
ASME
Working Pressure

For Natural Gas Or Propane
Manufactured by:
ECR International Inc.
2201 Dwyer Avenue, Utica, NY 13501
Tel. [phone]
www.ecrinternational.com
PN 240013259 REV. D [08/15/2021]

KEEP THIS MANUAL NEAR BOILER
RETAIN FOR FUTURE REFERENCE
2
VERIFY CONTENTS RECEIVED
Fully Assembled Boiler Vent Damper Draft Hood Pump (Optional)
*Drain Valve *ASME Safety Relief Valve *Tridicator
*Black Iron Fittings
(see parts list for sizes
and use)
Includes Essential
Documents and Warranty
11x17 Wire Diagrams
Document Package *Junction Box *Circulator Harness
* Items found in parts box included with your
boiler.
Information and specications outlined in this manual in eect at the
time of printing of this manual. Manufacturer reserves the right to
discontinue, change specications or system design at any time without
notice and without incurring any obligation, whatsoever.
For Parts lists see manual 24003260 included with your boiler literature package.
PN 240013259 Rev. D [08/15/2021]
VERIFY CONTENTS RECEIVED

3
TABLE OF CONTENTS
1 - Physical Data ..........................................................................................................4
1 - Dimensions .............................................................................................................4
2 - Safety Symbols And Warnings.................................................................................5
3 - Locating The Boiler .................................................................................................7
3.1 Installation Requirements ...................................................................................... 7
3.2 Minimum Clearances To Combustible Construction .................................................... 7
3.3 Recommended Clearances For Service..................................................................... 7
3.4 Boiler Location Considerations................................................................................ 8
4 - Connecting Supply & Return Piping.........................................................................9
4.1 Connection Locations ............................................................................................ 9
4.2 Safety Relief Valve Installation .......................................................................... 10
4.3 Flush And Rinse System ..................................................................................... 11
4.4 Water Treatment ............................................................................................... 11
4.5 Supply And Return Requirements ......................................................................... 12
4.6 Special Conditions .............................................................................................. 12
5 - Ventilation & Combustion Air ................................................................................19
5.1 Requirements .................................................................................................... 19
6 - Vent System Modication......................................................................................20
6.1 Removal Of Existing Boiler From Venting System .................................................... 20
7 - Vent Installation ...................................................................................................21
7.1 Check Your Chimney ........................................................................................... 21
7.2 Requirements .................................................................................................... 21
7.3 Chimney Inspection ............................................................................................ 21
7.4 Vent Pipe........................................................................................................... 21
8 - Vent Damper Installation & Instructions...............................................................22
8.1 Vent Damper ..................................................................................................... 22
9 - Connecting Gas Service .........................................................................................24
9.1 General ............................................................................................................. 24
9.2 Leak Check Gas Piping ........................................................................................ 24
10 - Electrical .............................................................................................................25
10.1 Electrical Wiring................................................................................................ 25
10.2 Thermostat Installation...................................................................................... 25
11 - Wiring Diagram ...................................................................................................26
12 - Lighting Instructions...........................................................................................28
12.1 Lighting Procedure For Boiler With Intermittent Pilot System................................... 28
12.2 Operating Instructions For Intermittent Pilot System.............................................. 28
 ........................................................................ 28
13 - Normal Sequence Of Operation ...........................................................................29
13.1 General ........................................................................................................... 29
14 - General Maintenance And Care Instructions........................................................30
14.1 Seasonal Startup .............................................................................................. 30
14.2 Clean Flue Gas Passageways ............................................................................. 30
14.3 General Maintenance......................................................................................... 31
14.4 Adjusting Gas Input .......................................................................................... 32
15 - Ratings & Data - Natural Gas & Propane Gas.......................................................33
Appendix A - Control Function ....................................................................................34
A.1 Control ............................................................................................................................34
A.2 Ignition............................................................................................................................35
A.3 Intermittent Pilot................................................................................................ 35
Appendix B - Vent Damper Installation ......................................................................37
B.1 Damper Installation ............................................................................................ 37
B.2 Vent Damper ..................................................................................................... 37
B.3 Vent Damper Harness - Molex Plugs...................................................................... 38
B.4 Vent Damper Troubleshooting Guide ..................................................................... 39
PN 240013259 Rev. D [08/15/2021]
TABLE OF CONTENTS

4
Model
UH15B-060K UH15B-095K UH15B-120K UH15B-150K UH15B-175K UH15B-205K UH15B-235K
# Sections 3 4 5 6 7 8 9
A Width (Jacket) 13-³/ 13-³/ 16-/ 1921-/ 27-¹/ 27-¹/
340 mm 340 mm 411 mm 483 mm 555 mm 700 mm 700 mm
BWidth W/ External Gas Valve 17- 19-
¹/  24-/ 27 -/" 32- ³/ 33-¹/
448 mm 489 mm 559 mm 632mm 705 mm 832 mm 851 mm
CVent Location (Half Width) 6-
³/ 6- ³/ 8-¹/" 9-/ 10-15/ 13- ³/ 13-
³/ 
171 mm 171 mm 206 mm 241 mm 278 mm 349 mm 349 mm
DHeight 32-¹/" 32-¹/" 32-¹/ 32-¹/ 32-¹/ 32-¹/ 32-¹/
816 mm 816 mm 816 mm 816 mm 816 mm 816 mm 816 mm
EDamper Height 5 ³/" 5 ³/" 6" 6" 6-³/" 6-³/" 6-³/"
146 mm 146 mm 152 mm 152 mm 178 mm 178 mm 178 mm
FDepth w/o Draft Hood
Installed
20" 20" 20" 20" 20" 20" 20"
508 mm 508 mm 508 mm 508 mm 508 mm 508 mm 508 mm
GDepth W/ Draft Hood Installed 24-1/8" 24-1/8" 24-1/8" 24-1/8" 24-1/8" 24-1/8" 24-1/8"
613 mm 613 mm 613 mm 613 mm 613 mm 613 mm 613 mm
H Flue Diameter 4" 5" 6" 6" 7" 7" 7"
102 mm 127 mm 153 mm 153 mm 178 mm 178 mm 178 mm
Supply & Return Tappings 1- ¹/ " NPT 1- ¹/ " NPT 1- ¹/ " NPT 1- ¹/ " NPT 1- ¹/ " NPT 1- ¹/ " NPT 1- ¹/ " NPT
Natural Gas Inlet 1/2" NPT 1/2" NPT 1/2" NPT 1/2" NPT 1/2" NPT 3/4" NPT 3/4" NPT
Relief Valve NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT
Drain Valve NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT 3/4" NPT
Heating Water Content, Gal
(Liter) 1.9 (7.2) 2.3 (8.8) 2.8 (10.5) 3.2 (12.2) 3.7 (13.9) 4.1 (15.6) 4.6 (17.3)
Air Cushion Tank, Gal (Liter) Estimate*
(Actual Based on System Size)
15 (57)* 30 (114)* 30 (114)* 30 (114)* 30 (114)* 30 (114)* 30 (114)*
Weight less pkg lbs (KG) 170 (77) 210 (96) 250 (114) 280 (128) 320 (145) 350 (159) 390 (177)
Shipping Weight lbs (KG) 215 (98) 250 (114) 295 (134) 335 (152) 385 (175) 420 (191) 465 (211)
1 - PHYSICAL DATA
"B"
"A"
"H"
"E"
"C"
"F"
"G"

(50.8 mm)

(549.3 mm)
5¹/
(139.7 mm )

16³/
7¹/
12¹/
(317.5 mm )
"D"
PN 240013259 Rev. D [08/15/2021]
1 - PHYSICAL DATA

5
2 - SAFETY SYMBOLS AND WARNINGS
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 potential personal injury hazards. Obey all
safety messages following this symbol to avoid
possible injury or death.
Become familiar with symbols identifying potential hazards.

2.1. Safety Information
WARNING
Do not tamper with or use this boiler for any
purpose other than its intended use. Failure to follow
these instructions could result in death or serious
injury. Use only manufacturer recommended parts
and accessories.
!
CAUTION
Laceration, burn hazard. Metal edges and parts
may have sharp edges and/or may be hot. Use
appropriate personal protection equipment to
include safety glasses and gloves when installing
or servicing this boiler. Failure to follow these
instructions could result in minor or moderate injury.
!!
NOTICE
Used to address practices not related to personal
injury.
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.
!
FOR YOUR SAFETY READ BEFORE OPERATING
Hot Water Can Scald!
Water heated to temperature for clothes washing,
dish washing and other sanitizing needs can scald and
cause permanent injury.

persons are more likely to be permanently injured by
hot water. Never leave them unattended in bathtub or
shower. Never allow small children to use a hot water
tap or draw their own bath.

description, or if state laws or local codes require
certain water temperatures at hot water taps, you
must take special precautions:
• Use lowest possible temperature setting.
• Install some type of tempering device, such as
an automatic mixing valve, at hot water tap or
water heater. Automatic mixing valve must be
selected and installed according to manufacturer's
recommendations and instructions.
• Water passing out of drain valves may be
extremely hot. To avoid injury:
• Make sure all connections are tight.
• 
DANGER
!
Water
Temperature
Seng
1st Degree Burn
Exposure Time For
An Adult
2nd and 3rd Degree Burn
Exposure Time For An
Adult
120° F 1 minute 5 minutes
130° F 5 seconds 30 seconds
140° F 2 seconds 5 seconds
150° F 1 second 1.5 seconds
160° F Instantaneous 0.5 seconds
Note: Warning for Infants, Children, and Elderly:
Great care must be taken when exposing the
aforementioned groups to warm or hot water as they
can be badly burned in exposure times less than half
of the time for an adult.
PN 240013259 Rev. D [08/15/2021]

6
WARNING
Keep boiler area clear and free from combustible

liquids.
DO NOT obstruct air openings to the boiler room.


result in personal injury or loss of life.
Installation and service of this boiler shall be performed

When this product is installed in the Commonwealth
of Massachusetts the installation shall be performed
by a Licensed Plumber or Licensed Gas Fitter.
!
WARNING
Combustion chamber insulation in this product

can be converted to cristobalite in very high
temperature applications. The International Agency
for Research on Cancer (IARC) has concluded,
Crystalline silica inhaled in the form of quartz
or cristobalite from occupational sources is
carcinogenic to humans (Group1). Avoid breathing
dust and contact with skin and eyes. Use NIOSH

respirator is based on the OSHA requirements
for cristobalite at the time this document was
written. Other types of respirators may be needed
depending on the job site conditions. Current
NIOSH recommendations can be found on the
NIOSH website https://www.cdc.gov/niosh/topics/
silica/. NIOSH approved respirators, manufacturers,
and phone numbers are also listed on this website.

and eye protection. Apply enough water to the
combustion chamber lining to prevent dust. Wash
potentially contaminated clothes separately from
other clothing. Rinse clothes washer thoroughly.
NIOSH stated First Aid. Eye: Irrigate immediately.
Breathing: Fresh air.
!
2 - SAFETY SYMBOLS AND WARNINGS
2.2 For Your Safety2.2 For Your Safety
Manufacturer recommends a carbon monoxide detectorManufacturer recommends a carbon monoxide detector


jurisdictions may, by law, require.jurisdictions may, by law, require.
WARNING
Fire, Explosion, Asphyxiation, Electrical shock
hazard! Flooding will result in damages such as
electrical problems, corrosion, inoperative parts,
mold and other unforeseen issues which can
occur over time. Any equipment determined by

excess of water or other liquid, shall be replaced.
Failure to follow these directions will result in a
Hazardous Situation.
!
WARNING
This prod uct contains Fibrous glass. Fibrous glass


human carcinogen. When disturbed as a result of

and, if inhaled, may be hazardous to your health.
May cause irritation to skin, eyes and respiratory
tract. Adhere to the following precautions and

have been listed by the State of California as a
possible cause of cancer through inhalation. Avoid
breathing dust and contact with skin and eyes. Use

of respirator is based on the OSHA requirements
for Fibrous glass at the time this document was
written. Other types of respirators may be needed
depending on the job site conditions. Current NIOSH
recommendations can be found on the NIOSH
website https://www.cdc.gov/niosh/ approved
respirators, manufacturers, and phone numbers are
also listed on this website. Wear long-sleeved, loose

potentially contaminated clothes separately from
other clothing. Rinse clothes washer thoroughly.
Follow all Local, State and Federal guidlines for
disposal.
NIOSH stated First Aid. Eye: Irrigate immediately.
Breathing: Fresh air.
!
PN 240013259 Rev. D [08/15/2021]

7
WARNING
Fire hazard! Do not install boiler on carpeting.
Failure to follow these instructions could result in
death or serious injury.
!
Minimum Clearances To Combustible Construction
(As Seen From Above)
3 - LOCATING THE BOILER
CAUTION
Boiler weight exceeds 200 pounds (90.7 kg). Do not
lift boiler without assistance.
!!
1. Installation shall conform to the requirements of 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. Where required
by the authority having jurisdiction, the installation
must conform to the Standard for Controls and Safety
Devices for Automatically red Boilers, ANSI/ASME
CSD-1.
2. 
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.
3. Boiler has met safe lighting and other performance
criteria with the gas manifold and control assembly on
the boiler per the latest revision of ANSI Z21.13/CGA
4.9.
4. Install boiler such that gas ignition system components
are protected from water (dripping, spraying, rain,
etc.) during appliance operation and service, (circulator
replacement, condensate trap, control replacement,
etc.).
5. Locate boiler on level, solid base as near chimney as
possible and centrally located with respect to heat
distribution system as practical.
6. Horizontal vent run to chimney shall be as short as
practicable. Refer to NFPA 54 to determine maximum
permissible horizontal run for chimney type and height.
7. 
equipment.
8.  Do not install
boiler on carpeting.
9. 
liquids or vapors will be stored or used. See Table 3-1,
Contaminants.
10. Chimney shall be lined in a manner acceptable to the
authority having jurisdiction.
11. 
3.2 Minimum Clearances to Combustible
Construction
3.1 Installation Requirements


BOILER


Front
Control
Side
1. Minimum clearances to combustible construction are:
Top 10 inches (254 mm)
Front Alcove*
Flue Connector 6 inches (152 mm)
Rear 6 inches (152 mm)
Gas Valve Side (Right Side) 9 inches (229 mm)
Left Side 2 inches (51 mm)
Hot Water Piping Per Local Code

front of boiler. ANSI standard for alcove is 18 inches from
front of appliance to leading edge of side walls as shown
below.
NOTE: Greater clearances for access and servicing should
supersede fire protection clearances.
3.3 Recommended Clearances for Service
1. Allow 24 inches (610 mm) at front and one side for
servicing and cleaning.
2. When installed in utillity room, door should be wide
enough to allow largest boiler part to enter, or to permit
replacement of another applicance such as a water
heater.
PN 240013259 Rev. D [08/15/2021]

8
3.3 Boiler Location Considerations
• Ambient room temperature always above 32°F (0°C) to
prevent the potential of freezing.
• Drainage of water (or water/ antifreeze solution) during
boiler service or from safety relief valve discharge.
• Access to system water piping, gas supply, and
electrical service.
• 
of supporting the weight of the boiler, water, and
equipment.
• 
wet.
• Horizontal run to chimney shall be as short a possible.
3 - LOCATING THE BOILER
Items to Avoid Products Which May Contain These
Items Areas Where These Items May Be Found
Chlorine, Fluorine, and Compounds

Chlorinated waxes/cleaners
Chlorine-based swimming pool chemicals
Calcium chloride used for thawing
Sodium chloride used for water softening
Swimming pool or spa chemicals
De-icing salts or chemicals
Carbon Tetrachloride
Swimming pools and pool storage areas


Airborne Particulates
Drywall dust
Road or gravel dust
Dryer lint
Cat litter


Acids, Solvents, etc.
Paint, Varnish, Turpentine, etc.
Cleaning Solvents
Hydrochloric acid/muriatic acid
Cements, adhesives and glues
Photo processing plants
Garages with workshops

establishments
Laundry Chemicals
Laundry detergents, bleaches, fabric
softeners, etc.
Antistatic fabric softeners (dryer sheets)
Dry cleaning/laundry areas and
establishments
Other
Permanent wave solutions
Refrigerants (Freon, etc) (only where
the refrigerant may be leaking from the
appliance)
Beauty shops
Refrigeration repair shops
Notes:


passages possibly resulting in unsafe operation. In this case, unit servicing shall include


the room be generously ventilated (well in excess of combustible air requirements), and
homeowner seal laundry supply containers, and minimize room vapors.
. Piping allowing fresh air in should also be considered. See Section 5-1.
t
Table 3-1: CONTAMINANTS
• System piping exposed to freezing conditions: Use

manufacturer for use with closed water heating system.
Do not use automotive or ethylene glycol.
Maximum recommended mixture 50% gylcol.
PN 240013259 Rev. D [08/15/2021]

9
4 - CONNECTING SUPPLY & RETURN PIPING
4.1 Connection Locations
• Boiler has one supply and one return tapping on each
side (4 total). Boiler supplied with dust caps. Remove

water.
WARNING
Burn and scald hazard. Boiler supplied with dust caps
on supply and return tappings (4). Remove all four

Failure to follow these instructions could result in
death or serious injury.
!• Supply and return may be piped to either side of boiler,
as desired. Both supply and return shall be on same
side of boiler. Do not "cross pipe" as boiler may not
deliver adequate heat with cross piping. See Figure 4-1.
• ASME relief valve may be located o unused
supply tapping IN UPRIGHT POSITION ONLY.
• Drain valve may, as an option, be located on the return
line using a contractor supplied tee, piped right or left.
See Figure 4-3.
• Unused supply and return tappings may be capped, as
desired.
Figure 4-1 Piping Options
PIPING OPTIONS
THIS BOILER HAS TWO SUPPLY (OUTLET) AND TWO RETURN (INLET) TAPPINGS.
PIPE SUPPLY AND RETURN ON THE SAME SIDE (FIG. 1 & 2)
DO NOT CROSS PIPE! (FIG 3 & FIG 4)
FIG 1.
FIG. 2
FIG 3.
FIG 4.
FRONT
FRONT
FRONT
FRONT
RETURN
RETURN
SUPPLY
SUPPLY
. A . B
. C . D
PIPING OPTIONS
THIS BOILER HAS TWO SUPPLY (OUTLET) AND TWO RETURN (INLET) TAPPINGS.
PIPE SUPPLY AND RETURN ON THE SAME SIDE (SEE FIG. A AND B)
DO NOT CROSS PIPE - (SEE FIG. C AND D)
PN 240013259 Rev. D [08/15/2021]

10
WARNING
Burn and scald hazard. Safety relief valve could
discharge steam or hot water during operation.
Install discharge piping per these instructions. Failure
to follow these instructions could result in death or
serious injury.
!
WARNING
Burn and scald hazard. Safety relief valve shall be
installed with spindle in upright position only,
following ASME BPV code. Failure to follow these
instructions could result in death or serious injury.
!
4.2 Safety Relief Valve Installation
See Figure 4-2
Discharge line shall be installed to relief valve outlet
connection to avoid burns, scalding, or water damage due
to discharge of steam and/or hot water during operation.
Discharge line shall:
A. connect to relief valve outlet and piped down to safe
point of disposal. Check local codes for maximum

discharge.
B. be of pipe size equal to or greater than that of
the relief valve outlet over the entire length of
discharge line;
C. 
relief valve and discharge to atmosphere (do not
plug or place any obstruction in discharge line.
D. terminate freely to atmosphere where any discharge
will be clearly visible and at no risk of freezing;
E. allow complete drainage of the valve and the
discharge line;
F. be independently supported and securely anchored
to avoid applied stress on the relief valve;
G. be as short and straight as possible;
H. terminate with plain end (not threaded);
I. be constructed of material suitable for exposure to
temperatures of 375° F (191°C); or greater.
Refer to local codes and appropriate ASME Boiler
and Pressure Vessel Code for additional installation
requirements.
Do Not Install
Pressure
Relief Valve
Horizontally
4 - CONNECTING SUPPLY & RETURN PIPING
Figure 4-2 Safety Relief Valve
Check local codes
for maximum

or allowable safe
point of discharge.
Discharge Line
Safety Relief Valve
Alternate Location
Piped in Supply Line
(Contractor Supplied
Fittings)
Figure 4-3 Optional Locations for Drain Valve
Left Side Drain
Valve Location With
Standard
Manufacturer Supplied
Hardware
Optional Right side Drain
Valve Location with
Contractor Supplied Tee
Gas Valve Location
Connection
PN 240013259 Rev. D [08/15/2021]

11
4 - CONNECTING SUPPLY & RETURN PIPING
4.3 Flush and Rinse System
Flush the entire system and rinse thoroughly to ensure no
sludge will be introduced into the heating body of the boiler.

connected to the high point of the heating system.
WARNING
• Poison hazard. Ethylene glycol is toxic. Do not
use ethylene glycol.
• Never use automotive or standard glycol
antifreeze, even ethylene glycol made for hydronic
systems.
• Ethylene glycol can attack gaskets and seals used
in hydronic systems.
• Do not use petroleum based cleaning or sealing
compounds boiler system.
• 
water.
• Use only inhibited propylene glycol solutions

use with closed water heating system.
• 
glycol before installing new Boiler.
• Provide user with Material Safety Data Sheet

!
NOTICE
If damage due to frozen pipes is a possibility, install
appropriate safeguards and alarms on the heating
system to prevent property damage due to frozen
and burst pipes should the boiler heating system
become inoperative due to a power outage, safety
lockout or component failure.
4.4 Water Treatment
Manufacturer recommends a water analysis be done on

based on the analysis results. For hard water or pH below
7.0 consult your local water treatment company.
• If CH water is very hard or full of impurities, it must be

or malfunction could be caused. Recommended water
quality is :
o Hardness Less than 150 mg/L
o Acidity level 7-8 pH
o Sediments Particle size less than 50 micron
• If the water quality is outside these ranges, consult a local
water treatment specialist for recommendations.
• If the water is treated, do not use petroleum based
products or products containing mineral oil or hydrocarbons
in order to avoid likely damage to parts made from rubber
compounds (o-rings).
PN 240013259 Rev. D [08/15/2021]

12
4 - CONNECTING SUPPLY & RETURN PIPING
4.5 Supply and Return Requirements
1. Boiler used in connection with refrigeration system,
install so chilled medium is piped in parallel with boiler
with appropriate valves to prevent chilled medium from
entering boiler. See Figure 4-4 page 13.
2. Boiler piping system of hot water boiler connected to
heating coils located in air handling units where they
may be exposed to refrigerated air circulation must be

means to prevent gravity circulation of boiler water
during cooling cycle.
3. Hot water boilers installed above radiation level or
as required by authority having jurisdiction must

installed).
4.6 Special Conditions
• System piping exposed to freezing conditions: Use

manufacturer for use with closed water heating
system. Do not use automotive or ethylene glycol.
• Boiler installed above radiation level (or as required by

is provided in boiler.
• Boiler used in connection with refrigeration system.
Install piping in parallel with boiler, with appropriate
valves to prevent chilled medium from entering boiler.
• System piping connected to heating coils located in air
handling unit exposed to refrigerated air circulation.

to prevent gravity circulation of boiler water during
cooling cycle.
Do not expose boiler and piping to freezing
temperatures.
Note
WARNING

resulting from condensate induced corrosion may
block boiler passages, resulting in carbon monoxide

temperature is under 130°F. Failure to follow these
instructions could result in death or serious injury.
!
4. Boiler connected to heating system utilizing multiple
zoned circulators, each circulator must be supplied with

5. Bypass piping gives ability to adjust supply boiler water

This method of piping, however, is not typically
required for baseboard heating systems. Typical
installations where bypass piping is required are as
follows:
A. This method is used to protect boilers from
condensation forming due to low temperature return
water ( Below 130° F). Generally noticed in large
converted gravity systems or other large water
volume systems. Figures 4-5 and 4-6 pages 14-15.
B. These methods are used to protect systems using
radiant panels and material they are encased in
from high temperature supply water from boiler and
protect 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 supply and return piping.
6. Installation using circulators and zone valves are
shown in Figures 4-4 through 4-9. For further piping
information refer to AHRI Installation and Piping
Guide.
7. Install discharge piping from safety relief valve. See
Warning, Page 10 and Figure 4-2.
PN 240013259 Rev. D [08/15/2021]

13
4 - CONNECTING SUPPLY & RETURN PIPING
Circulators in following illustrations are mounted on system supply side, mounting on system return side is also
acceptable practice.
Figure 4-4 - Circulators Mounted on Supply System, Boiler Used In Conguration with Chiller
System. See Special Conditions, Page 10
DRAIN
BACK FLOW VALVE
PIPING LEGEND:
4.6 Special Conditions
• System piping exposed to freezing conditions: Use

manufacturer for use with closed water heating
system. Do not use automotive or ethylene glycol.
Do not expose boiler and piping to freezing
temperatures.
Note
• Boiler installed above radiation level (or as required
by authority having jurisdiction). Integral low water
switch is provided in boiler.
• Boiler used in connection with refrigeration system.
Install piping in parallel with boiler, with appropriate
valves to prevent chilled medium from entering boiler.
• System piping connected to heating coils located in air
handling unit exposed to refrigerated air circulation.

to prevent gravity circulation of boiler water during
cooling cycle.
PN 240013259 Rev. D [08/15/2021]

14
4 - CONNECTING SUPPLY & RETURN PIPING
Figure 4-5 - Bypass Piping With Automatic Mixing Valve
BACK FLOW VALVE
PIPING LEGEND:
PURGE
VALVE
DRAIN
VALVE
ASME
RELIEF
VALVE
Back Flow
Valve
PN 240013259 Rev. D [08/15/2021]

15
4 - CONNECTING SUPPLY & RETURN PIPING
Figure 4-6 - Bypass Piping - Fixed Low Temp Only With Zone Valve
BACK FLOW VALVE
PIPING LEGEND:
ASME
RELIEF
VALVE
**
*Manually adjust until proper system
temperature is reached.
Drain
Valve
Drain
Valve
PN 240013259 Rev. D [08/15/2021]

16
4 - CONNECTING SUPPLY AND RETURN PIPING
Figure 4-7 - Bypass Piping (4-Way Valve Option With Circulator On Supply side)
BACK FLOW VALVE
PIPING LEGEND:
ASME
RELIEF
VALVE
Back Flow
Valve
Drain
Valve
PN 240013259 Rev. D [08/15/2021]

17
Figure 4-8 - Single Zone System With DHW Priority
BACK FLOW VALVE
PIPING LEGEND:
4 - CONNECTING SUPPLY AND RETURN PIPING
ASME
RELIEF
VALVE
Back Flow
Valve
Drain
Valve
Purge
Valve
PN 240013259 Rev. D [08/15/2021]

18
T & P Relief
Valve to
Drain
Cold
Water
Supply
Optional
Indirect
DHW Tank
Make-up
Water
Supply
Tank
Sensor
CH /System
Pump
ASME
Relief
Valve
1
DHW Pump
* Hot
Water
Supply
Tempered
TO SYSTEM
FROM SYSTEM
Drain
Valve
12” (305mm) Recommended
distance. Do not exceed 12".
Note
Note * Manufacturer requires all domestic
hot water (DHW) installations use
an anti-scald valve. Local codes
may require additional equipment
(expansion tank, relief valves,
etc.) Select and size equipment
to suit installation and meet code
requirements.
Note
Refer to pump manufacturer
literature for proper pump sizing.
1
4 - CONNECTING SUPPLY AND RETURN PIPING
BACK FLOW VALVE
PIPING LEGEND:
Figure 4-9 - Multi Zone System With Zone Valves And DHW Priority (With Zone Valve)
Back Flow Valve
PN 240013259 Rev. D [08/15/2021]

19
5 - VENTILATION & COMBUSTION AIR
Room Cubic Feet Volume
#
Sections
Input
[(BTU/HR)/1,000]
Standard
Method
Known Air Inltration Rate Method (ACH - Air Changes Per Hour)
0.1 0.2 0.3 0.4 0.5 0.6
3 59,000 2950 12390 6195 4130 3098 2478 2065
4 92,500 4625 19425 9712.5 6475 4856 3885 3238
5 120,000 6000 25200 12600 8400 6300 5040 4200
6 149,000 7450 31290 15645 10430 7823 6258 5215
7 175,000 8800 36960 18480 12320 9240 7392 6160
8 205,000 10250 43050 21525 14350 10763 8610 7175
9 235,000 11750 49350 24675 16450 12338 9870 8225
Table 5-1 - Space With Boiler Only
5.1 Requirements
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. If inadequate makeup air is suspected it is
always acceptable to add additional ventilation.
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 jurisdiction.
• Mechanical Air Supply. Provide minimum of 0.35 cfm
per [(BTU/HR)/1,000]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

minimum volume not available.
A. Standard Method. Cannot be used if known air

Table 3 for space with boiler only. Use equation for
multiple appliances.
3x Total Input [(BTU/HR)/1,000]
B. 
space with boiler only. Use equation for multiple

 21 ft3
[(BTU/HR)/1,000].
C. Refer to National Fuel Gas Code for opening
requirements between connected indoor spaces.
• All Outdoor Air. Provide permanent opening(s)
communicating directly or by ducts with outdoors.
A. Two Permanent Opening Method. Provide opening
commencing within 12 inches of top and second
opening commencing within 12 inches of bottom of
enclosure.
Direct communication with outdoors or
communicating through vertical ducts. Provide
minimum free area of 1 in² per 4 [(BTU/
HR)/1,000] of total input rating of all appliances
in enclosure.
Communicating through horizontal ducts.
Provide minimum free area of 1 in² per 2 [(BTU/
HR)/1,000] of total input rating of all appliances
in enclosure.
B. One Permanent Opening Method. Provide opening
commencing within 12 inches of top of enclosure.
Provide minimum clearance of 1 inch on sides/back
and 6 inches on front of boiler (does not supersede
clearance to combustible materials).
• Refer to 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
providing 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 [(BTU/
HR)/1,000] (120 kW).
• Section 8.4 when combination of appliances has total
input exceeding 400 [(BTU/HR)/1,000] (120 kW).
• Refer to Natural Gas and Propane Installation Code

or structure where boiler is installed, including air
supply openings and ducts.
WARNING
Asphyxiation Hazard! Provide enough air openings

and allow for consistent, guality combustion.
Do not obstruct air openings. Follow instructions
below, to maintain adequate combustion air.
Failure to follow these instructions good result in
ignition failure, overheating, carbon monoxide, and

!
PN 240013259 Rev. D [08/15/2021]

20
6 - VENT SYSTEM MODIFICATION
Figure 6-1 - Typical Masonry Chimney Requirements
When an existing boiler is removed from a common venting
system, the system is likely too large for proper venting of
appliances still connected to it. If this occurs, follow this
test procedure:
At 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 an unused opening in the common venting
system.
2. Visually inspect the venting system for proper size and
horizontal pitch and determine there is no blockage or

which could cause an unsafe condition.
3. Insofar 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 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

dampers.
4. Place in operation the appliance being inspected. Follow
the lighting instructions. Adjust thermostat so appliance
will operate continuously.
5. Test for spillage at the draft hood relief opening after

a match or candle, or smoke from a cigarette, cigar or
pipe.
6. Minimum draft should be -.02 w.c.
7. After it has been determined that each appliance
remaining connected to a common venting system
properly vents when tested as outlined above, return

any other gas burning appliances to their previous
condition of use.
8. Any improper operation of the common venting system
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.
9. Draft pressure must be negative under all conditions
with all aplliances operating.
6.1 Removal Of Existing Boiler From Venting System

Type B Vent Masonry Chimney Requirements
PN 240013259 Rev. D [08/15/2021]