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
42
5. Connect the boilers in a daisy chain conguration as shown 
below. It is best to wire the boilers using the shortest wire runs 
rather than trying to wire them in the order that they are addressed. 
The communication bus jacks on the customer connection panel 
are interchangeable so you can use either one or both in any order 
to connect the cable.
If you have connected the boilers to each other properly, there will 
be no open communication connection ports.
M. Cascade Master Pump and Sensor Wiring
1. Connect the system pump hot wire to the terminal marked 8. 
2. Connect the system pump neutral to the 2 terminal and the pump 
ground wire to the 3 terminal. 
3. Connect a jumper wire from the 120 VOLT terminal to the 9 
terminal. 
4. Connect the boiler pump to the terminals marked 1 (HOT), 2 
(NEUT) and 3 (GND).
5. Connect system pipe sensor to terminals marked 10 and 11.
6. In cascaded systems where the ENTIRE set of boilers provides 
DHW supply, connect the DHW pump to the terminals marked 4 - 
HOT, 5 - NEUT, 6 - GND on the master boiler.
N. Cascade Follower Pump and Sensor Wiring
1. Connect the boiler pump to the terminals labeled 1 (HOT), 2 (NEUT), 
and 3 (GND). 
2. In cascaded systems where ONLY ONE boiler provides DHW supply, 
connect the DHW pump to the terminals marked 4 - HOT, 5 - NEUT, 6 - 
GND on the boiler that will meet DHW demand. 
3. An alarm bell or light can be connected to the alarm contacts of the 
follower boiler. The normally closed alarm contact may be used to turn 
a device o if the boiler goes into lockout mode. The alarm contacts 
are rated 5 amps at 120 VAC.
To connect an alarm device, connect the power for the device to 
the ALARM COM terminal. Connect the alarm device hot wire to the 
ALARM NO terminal. Connect the neutral or return of the alarm device 
to the neutral or return of the power for the alarm device. 
To connect a device that should be powered o during a boiler lockout 
condition, follow the same instructions as above except use the ALARM 
NC terminal rather than the ALARM NC terminal.
Note that in a cascade system the alarm output of the boiler addressed 
as #1 will also be active if the master boiler has a lockout condition. The 
alarm output of boilers addressed as 2-7 will only activate an alarm if a 
lockout condition occurs on that specic boiler.
See Figure 32 for Cascade Master and Follower Wiring detail.
Figure 32 - Cascade Master and Follower Wiring










