Install Instructions
Table Of Contents
- UNIT HEATER INSTALLATION/OPERATION/MAINTENANCE: (MODEL UBX: STANDARD POWER VENT BLOWER TYPE, MODEL UBZ: SEPARATED-COMBUSTION BLOWER TYPE, MODEL UDX: STANDARD POWER VENT FAN TYPE, MODEL UDZ: SEPARATED-COMBUSTION FAN TYPE)
- TABLE OF CONTENTS
- GENERAL INFORMATION
- INSTALLATION
- CONTROLS
- OPERATION
- ADJUSTMENTS
- MAINTENANCE
- Service Checklist
- Maintenance Procedures
- Burner Maintenance
- Burner Orifice Maintenance
- Heat Exchanger Maintenance
- Ignition System Maintenance
- Maintenance of Fan Motor, Fan Blades, and Fan Guard
- Venter Motor and Wheel Assembly Maintenance
- Operating Gas Valve Maintenance
- Pressure Switch Maintenance
- High Temperature Limit Control Maintenance
- Flame Rollout Switch Maintenance (Model UDZ Unit Sizes 030–125 Only)
- Interlock Door Switch Maintenance (Models UBZ and UDZ Only)
- Transformer Maintenance
- Disconnect Switch Replacement (Models UBZ and UDZ Only)
- Vent or Vent/Combustion Air System Maintenance
- TROUBLESHOOTING
- INSTALLATION RECORD (TO BE COMPLETED BY INSTALLER)
- FIGURES
- Figure 1. Heater Throw Patterns (Refer to Table 2 and Table 3)
- Figure 2. Dimensions—Models UBX and UBZ (Refer to Table 4)
- Figure 3. Dimensions—Models UDX and UDZ (Refer to Table 5)
- Figure 4. Confined Space Combustion Air Openings (Refer to Table 8)
- Figure 5. Plugging Unused Suspension Points (Models UBZ and UDZ Only)
- Figure 6. Option CK8 or CK10 Hanger Kit
- Figure 7. Option CK22 Hanger Kit
- Figure 8. Heater Suspension Using Field-Supplied Threaded Rods
- Figure 9. Gas Connections
- Figure 10. Supply Wiring Entrance and Control Connection Terminal Strip
- Figure 11. Circuit Board (DSI Control Module)
- Figure 12. Component Locations (Typical)
- Figure 13. Gas Valve ON/OFF Control
- Figure 14. Pressure Switch
- Figure 15. Gas Valves
- Figure 16. Typical Burner Assembly
- Figure 17. Ignitor Spark Gap
- Figure 18. Fan Blade Positioning and Spacing
- Figure 19. Venter Motor and Wheel Assembly
- Figure 20. Replaceable Components
- Figure 21. DSI Control Module Troubleshooting Flowchart
- TABLES
- Table 1. Related Technical Manuals Available from Factory Distributor
- Table 2. Heater Throw Distances with Standard Horizontal Louvers at Mounting Heights of 5 to 18 Feet
- Table 3. Heater Throw Distances with Standard Horizontal Louvers at Mounting Heights of 1.5 to 5.5 Meters
- Table 4. Dimensions—Models UBX and UBZ
- Table 5. Dimensions—Models UDX and UDZ
- Table 6. Clearances to Combustibles
- Table 7. Unit Weights
- Table 8. Determining Confined Space Combustion Air Requirements
- Table 9. Technical Data for UBX and UBZ Models (Unit Sizes 030–125)
- Table 10. Technical Data for UBX and UBZ Models (Unit Sizes 150–400)
- Table 11. Technical Data for UDX and UDZ Models (Unit Sizes 030–125)
- Table 12. Technical Data for UDX and UDZ Models (Unit Sizes 150–400)
- Table 13. Field-Installed Options
- Table 14. Gas Supply Line Sizes
- Table 15. Gas Connection Sizes
- Table 16. Pressure Switch Settings
- Table 17. Circuit Board (DSI Control Module) Display Codes
- Table 18. Operating Sequence (Normal Heat Cycle)
- Table 19. Operating Sequence (Abnormal Heat Cycle)
- Table 20. Fault Modes
- Table 21. Required Manifold (Outlet) Gas Pressure
- Table 22. Inputs and Capacities by Elevation in US
- Table 23. Inputs and Capacities by Elevation in Canada
- Table 24. Fan Blade Spacing
- Table 25. General Troubleshooting
29
I-UBX-UBZ-UDX-UDZ (04-21) 1034344-0
Operating Sequences
Table 18 describes the heater’s normal operating sequence. Table 19 describes the heater’s abnormal heat cycle
functions. Table 20 describes the heater’s fault modes. Refer to Table 17 for LED indications.
Table 18. Operating Sequence (Normal Heat Cycle)
Step Condition Action
1. Call for
heat
Terminal W is energized
Thermostat calls for heat by energizing terminal W
Control determines whether limit switch is open or closed and if pressure switch is open
Limit switch is open
Control deenergizes gas valve, turns fan/blower motor onto heat speed, and runs venter motor
SSD displays “5”
Control is in soft lockout “L” before returning to normal operation
Pressure switch is closed
SSD displays “4”
Control waits indefinitely for pressure switch to open
Pressure switch is open Control proceeds to step 2
2. Prepurge
Venter motor is energized Control waits for pressure switch to close
Pressure switch not closed
within 30 seconds of venter
motor energizing
SSD displays “3”
Control maintains venter motor energized indefinitely as long as call for heat remains and
pressure switch is open
Pressure switch is proven
closed
Control begins prepurge
Flame is present at any time
during prepurge
Prepurge is restarted
Flame is present long
enough to cause lockout
Control runs venter motor and runs fan/blower motor on heat speed
When flame is no longer sensed, venter motor runs through post-purge and fan/blower motor
runs through selected delay OFF time
Control proceeds to soft lockout but still responds to open limit and flame
SSD displays “6” when lockout is due to undesired flame
Venter motor runs for
20-second prepurge time
Control proceeds step 3
3. Ignition
trial period
Spark and main gas valve
are energized
The venter remains energized
Flame is sensed during first
16 seconds
Control deenergizes spark and proceeds to heat fan/blower on delay
Flame is not sensed during
first 16 seconds
Control deenergizes spark and maintains gas valve energized for additional 1-second flame-
proving period
Flame is not present after
flame-proving period
Control deenergizes gas valve and proceeds with ignition retries as specified in Table 19:
abnormal function Ignition Retry
Flame is present after flame-
proving period
Control proceeds to step 4
4. Fan/blower
ON delay
30 seconds after gas valve
has opened
Control energizes fan/blower motor
Gas valve and venter motor
remain energized
Control proceeds to step 5
5. Steady
heat
Limit switch is closed
Control continuously monitors inputs
Pressure switch is closed
Flame is established
Thermostat call for heat
remains
Thermostat call for heat is
removed
Control deenergizes gas valve and proceeds to steps 6 and 7
6. Post-purge
Thermostat is satisfied
Venter motor remains on for 45-second post-purge period
7. Fan/blower
OFF delay
Fan/blower motor is deenergized after selected fan/blower OFF delay