Instructions / Assembly
Table Of Contents
- Part 1 - General Safety Information
 - Part 2 - Before You Start
 - Part 3 - Prepare the Boiler
- A. Locating the Boiler
 - B. Structure
 - C. Leveling
 - D. Clearances for Service Access
 - E. Wall Mounting Considerations
 - F. Wall Mounting Instructions
 - G. Residential Garage and Closet Installations
 - H. Exhaust Vent and Intake Pipe
 - I. Carbon Monoxide Detectors
 - J. Prevent Combustion Air Contamination
 - K. Removing a Boiler from a Common Vent System
 - K. Water Chemistry Requirements*
 - L. Technical Specifications
 
 - Part 4 - Piping
- A. General Plumbing Information
 - B. Relief Valve
 - C. Backflow Preventer
 - D. Potable Expansion Tank
 - E. Circulators
 - F. Hydronic Piping with Circulators, Zone Valves, and Multiple Boilers
 - G. Circulator Sizing
 - H. Check / Control Water Chemistry
 - I. Plumbing
 - J. Fill and Purge Heating System
 - K. Glycol Antifreeze Solutions
 - L. Zoning with Zone Valves
 - M. Zoning with Circulators
 - N. Multiple Boilers
 - O. Applications*
 
 - Part 5 - Venting
 - Part 6 - Condensate Removal
 - Part 7 - Wiring
- A. Installation Must Comply With
 - B. Field Wiring Terminations
 - C. Field Wiring
 - D. Line Voltage Wiring for Standard Boiler
 - E. Alarm Connections
 - F. Low Voltage Connections for Standard Boiler
 - G. Thermostat
 - H. Outdoor Sensor
 - I. Indirect Sensor
 - J. Optional 0-10 Volt Building Control Signal
 - K. Optional UL353 Low Water Cut-Off Interface Kit
 - L. Wiring of Cascade System Communication Bus
 - M. Cascade Master Pump and Sensor Wiring
 - N. Cascade Follower Pump and Sensor Wiring
 
 - Part 8 - Gas Connections
 - Part 9 - Start-Up Preparation
- A. Check / Control Water Chemistry
 - B. Check for Gas Leaks
 - C. Freeze Protection (When Used)
 - D. Fill and Test Water System
 - E. Purge Air from Water System
 - F. Check Thermostat Circuit(s)
 - G. Condensate Removal
 - H. Final Checks Before Starting Boiler
 - I. Setting Up a Single Boiler
 - J. Setting Up a Cascaded System
 - K. Lockout Condition
 - L. Cascade System Programming
 
 - Part 10 - Start-Up Procedure
 - Part 11 - Start-Up Procedures for the Installer
 - Part 12 - Troubleshooting
 - Part 13 - Maintenance
 - Part 14 - Shutdown
 - Part 15 - Installation Checklist
 - Part 16 - Maintenance Report
 - Part 17 - Replacement Parts
 

LP-387 Rev. 011 Rel. 006 Date 6.28.19
9
Do not mount the boiler to a hollow wall. Mount to the studs only.
Use extreme care not to drop the boiler or cause bodily injury 
while lifting or mounting the boiler onto the wall mount bracket.
Failure to follow these instructions could result in property 
damage, severe personal injury, or death.
Figure 3 - Recommended Service Clearances
This boiler must be installed upright in the vertical position as 
described in this manual. DO NOT attempt to install this boiler 
in any other orientation. Doing so will result in improper boiler 
operation and property damage, and could result in serious 
personal injury or death.
Always take future maintenance into consideration when locating 
the boiler. If the boiler is located in an installation location with 
limited clearances, it may be necessary to remove the boiler 
from the space to perform maintenance. Failure to consider 
maintenance when determining installation location could result 
in property damage.
All boilers eventually leak. Locate the boiler where any leakage 
from the relief valve, related piping, tank, or connections will 
not result in damage to surrounding areas or lower oors of the 
building. Any boiler should be installed in such a manner that if 
it should leak the resulting ow of water will not cause damage 
to the area in which it is installed. If the boiler is installed in 
a location where a leak could cause damage, it is required to 
provide containment measures. Such measures include but are 
not limited to: a properly sized drain pan installed beneath the 
boiler and piped to an open drain line, or installing the boiler on 
a concrete oor pitched to a free owing drain. Failure to provide 
containment measures is the sole responsibility of the owner and/
or installer. Leakage damages ARE NOT covered by warranty. 
In addition, water leak detection devices and automatic water 
shuto valves are readily available at plumbing supply houses. IT 
IS HIGHLY RECOMMENDED BY THE MANUFACTURER TO INSTALL 
WATER LEAK DETECTION DEVICES AND AUTOMATIC SHUTOFF 
VALVES IN ANY BOILER INSTALLATION WHERE A LEAKAGE OF 
WATER COULD RESULT IN PROPERTY DAMAGES. 
The space must be provided with combustion / ventilation air 
openings correctly sized for all other appliances located in the same 
space as the boiler. The boiler cover must be securely fastened to 
prevent the boiler from drawing air from the boiler room. This is 
particularly important if the boiler is in a room with other appliances. 
Failure to comply with the above warnings could result in substantial 
property damage, severe personal injury, or death.
E. Wall Mounting Considerations
These boilers are wall mounted. Use only the wall mounting 
instructions included in this manual.
Ensure the wall that the boiler is intended to be mounted on is 
comprised of cement, brick, block, or wooden studs spaced 16” apart 
from center. Ensure the wall is capable of supporting at least 250 lbs 
(115 kg) for 55 – 110 models, 300 lbs (136 kg) for 155 – 285 models, and 
500 lbs (227 kg) for 399 model.
If ooding is possible, elevate the boiler to prevent oodwater from 
reaching the boiler.
Ensure the boiler is installed in a location that minimizes the risk of 
water damage due to leaking valves, pumps, unions, etc.
The mounting location must be capable of carrying the weight of the 
boiler and its related components. If the mounting location cannot 
support a minimum of 250 lbs. (115 kg), it is recommended to locate 
the boiler in a mounting location that can support the minimum 
weight. Failure to comply with the above and properly mount the 
boiler could result in substantial property damage, severe personal 
injury, or death.
This boiler is too heavy for one person to lift. It is highly recommended 
to install the boiler with two people. Use caution as to not drop the 
boiler, which could damage the boiler and cause property damage 
and/or severe personal injury. Verify that the boiler is properly and 
securely mounted before leaving unsupervised. Failure to comply 
with the above and properly mount the boiler could result in 
substantial property damage, severe personal injury, or death.
F. Wall Mounting Instructions
Minimum Clearances from Combustible Materials
•  Hot water pipes - at least 1” from combustible materials
•  Exhaust vent pipe - at least 1” from combustible materials










