Revision: UB-UD-GC (01-24) 1034364-H
Supersedes: UBX-UBZ-UDX-UDZ-GC (05-23) 1034364-G

GAS CONVERSION KIT INSTALLATION FOR GAS-FIRED
UNIT HEATERS
MODELS UBX, UBXC, UBZ, UDX, UDXC, UDZ, UDAP, UDAS, UDBP, AND UDBS

GENERAL INFORMATION

These gas conversion kits are for gas-fired unit heaters equipped with either a single-stage or two-stage gas valve.
When converting fuels, it is necessary to have the complete heater model. The identifying model number can be found on the heater rating plate. The rating plate identifies only original equipment so also compare the label on the gas valve with the description  listed.

Table 1.  Model Configuration

Model| Configuration| Model| Configuration
UBX, UDBP| Standard power-vent blower-type| UBZ, UDBS| Separated-combustion blower-type
UDX, UDAP| Standard power-vent fan-type| UDZ, UDAS| Separated-combustion fan- type
UBXC| Convertable power-vent blower-type | UDXC| Convertable power-vent fan-type
***** Standard units may be field-converted to separated-combustion units.

Important Safety Information
Refer to the installation manual provided with the heater for important safety information. Pay attention to all dangers, warnings, cautions, and notes highlighted in this manual. Safety markings should not be ignored and are used frequently throughout to  designate a degree or level of seriousness.

 ⚠ DANGER ⚠

• All gas conversion must be done by a qualified service person in accordance with these instructions and in compliance with all codes and requirements. In Canada, gas conversion shall be carried out in accordance with the requirements of the Provincial  Authorities having jurisdiction and in accordance with the requirements of the CAN/CGA-B149.1 and CAN/ CGA-B149.2 installation code.

• The gas burner in this gas-fired equipment is designed to provide safe complete combustion.
  However, if the installation does not permit the burner to receive the proper supply of combustion air, complete combustion may not occur. The result is incomplete combustion, which produces carbon monoxide, a poisonous gas that can cause death.

• Safe operation of indirect-fired gas burning equipment requires a properly-operating vent system that vents all flue products to the outside atmosphere. Failure to provide proper venting will result in a health hazard that could cause serious personal injury  or death.

• For all heater installations, always comply with the combustion air requirements in the installation codes and instructions. Standard power vent heaters installed in a confined space must be supplied with air for combustion as required by code and in the  heater installation manual. On separated-combustion heaters, install either the horizontal or vertical combustion air/vent system using the concentric adapter supplied. Combustion air at the burner should be regulated only by manufacturer-provided  equipment. Never restrict or otherwise alter the supply of combustion air to any heater. Maintain the vent or vent/combustion air system in structurally sound and proper operating condition.

• Improper installation, adjustment, alteration, service, or maintenance can cause property damage, injury, or death. Read the installation, operation and maintenance instructions thoroughly before installing or servicing this equipment.

DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

Heater Component Locations

CONVERSION KIT SELECTION

⚠ DANGER ⚠
The conversion kit is to be selected and installed by a qualified service person in accordance with these instructions and in compliance with all codes and requirements of authorities having jurisdiction. Failure to follow instructions could result in death, serious  injury, and/or property damage. The qualified agency performing this work assumes responsibility for this conversion.

Each conversion kit includes two or three spring kits and burner orifices for multiple unit sizes. Some parts will not be used—carefully select the parts to be used.

Table 2.  Conversion Kit Common Components—All Models

Component| Description| PN
Tape| Conversion| 64391
Disk| Propane (included in all NG to LP kits)| 37752
Natural gas (included in all LP to NG kits)| 1401
Label| High-elevation adjustment (used only at installation elevations >2000 feet (>610 meters))| 197062
Burner orifice| Refer to Table 3
Table 3.  Burner Orifices—All Models

Unit Size (MBTUh)| Model| Natural Gas| Propane
Orifice Size/Marking| PN| Orifice Size/Marking| PN
30| UDAP, UDAS, UDBP, UDBS| #37| 196853| 1.60 mm| 196844
UBX, UBZ, UDX, UDZ| #39| 196852
UBXC, UDXC| #37| 196853| 1.65 mm| 1043044
45| UDAP, UDAS, UDBP, UDBS| #30| 196838| #48| 196845
UBX, UBZ, UDX, UDZ| 3.10 mm| 120144
UBXC, UDXC| 3.20 mm| 196847| #47| 1043047
60| UDAP, UDAS, UDBP, UDBS| 3.70 mm| 196839| 2.30 mm| 196846
UBX, UBZ, UDX, UDZ| #28| 124969| 2.25 mm| 1034350
UBXC, UDXC| 3/32 inch| 1043046
75| UDAP, UDAS, UDBP, UDBS| #19| 196855| #39| 196852
UBX, UBZ, UDX, UDZ| #22| 196361| #40| 120137
UBXC, UDXC| #20| 120153| #39| 196852

100

| UDAP, UDAS, UDBP, UDBS| #10| 120158| 3.00 mm| 196854
UBX, UBZ, UDX, UDZ| #14| 208247| #32| 120141
UBXC, UDXC| #12| 120157

125

| UDAP, UDAS, UDBP, UDBS| #4| 196840| 3.20 mm| 196847
UBX, UBZ, UDX, UDZ| #10| 120158| 3.10 mm| 120144
UBXC, UDXC| #6| 1043045| #30| 196838
150| UDAP, UDAS, UDBP, UDBS| 5.90 mm| 131581| 9/64-inch| 196898
UBX, UBZ, UDX, UDZ| 5.60 mm| 208243| 3.50 mm| 120148
UBXC, UDXC
175| UDAP, UDAS, UDBP, UDBS| E| 196891| #24| 196899
UBX, UBZ, UDX, UDZ| 6.00 mm| 208245| #27| 120149
UBXC, UDXC| C| 120164| #24| 196899
200| UDAP, UDAS, UDBP, UDBS| 6.80 mm| 196892| 4.10 mm| 196900
UBX, UBZ, UDX, UDZ| F| 120167
UBXC, UDXC| #19| 196855
225| UDAP, UDAS, UDBP, UDBS| 6.95 mm| 221121| 11/64 inch| 196901
UBX, UBZ, UDX, UDZ
UBXC, UDXC
250| UDAP, UDAS, UDBP, UDBS| L| 208255| #14| 196902
UBX, UBZ, UDX, UDZ| 4.60 mm| 1034352
UBXC, UDXC
300| UDAP, UDAS, UDBP, UDBS| 8.00 mm| 221122| #8| 196903
UBX, UBZ, UDX, UDZ| 7.80 mm| 208253
UBXC, UDXC
350| UDAP, UDAS, UDBP, UDBS| 8.70 mm| 221123| #3| 196904
UBX, UBZ, UDX, UDZ| 8.50 mm| 1034354| 5.40 mm| 1034353
UBXC, UDXC
400| UDAP, UDAS, UDBP, UDBS| 9.60 mm| 196897| 5.80 mm| 196905
UBX, UBZ, UDX, UDZ| 9.20 mm| 1034355
UBXC, UDXC| 9.60 mm| 196897
Table 4.  NG to LP Kit-Specific Components for UBX, UBXC, UBZ, UDX, UDXC, and UDZ Models

Component| Description| Gas Valve (Honeywell Model No.)
1/2-Inch, Single- Stage (VR8105K2942, VR8205K2957,
or
VR8215T1239)| 1/2-Inch, Single- Stage (VR8105K2942, VR8205K2957,
or
VR8215T1239)
or
1/2-Inch, Two-Stage (VR8105N2949 or VR8205N2921)| 1/2-Inch, Single-Stage (VR8205K2957
or
VR8215T1239)
or
1/2-Inch, Two-Stage (VR8205N2921)| 1/2-Inch, Single-Stage  (VR8205K2957
or
VR8215T1239), 3/4- Inch Single-Stage (VR8305K4241),
or
1/2-Inch, Two-Stage  (VR8205N2921
or
VR8305N4297)| 3/4-Inch Single-Stage
(VR8305K4241)
or
3/4-Inch, Two-Stage  (VR8305N4297)
Unit Size (MBTUh)
30, 45| 60, 75| 100, 125| 150, 175| 200, 225, 250| 300, 350, 400
Model
UBX, UBZ| UDX, UDZ| UBX, UBZ| UDX, UDZ| UBX, UBZ, UDX, UDZ
Kit PN
1036541R| 1036536R| 1036542R| 1036537R| 1036538R| 1036539R| 1036540R| 1036543R
Model
UBXC, UDXC
Kit PN
1043184| 1043185| 1043186| 1043187| 1043188| 1043189
Component PN

Spring kit

| #393691 for single- stage valve VR8105, VR8205, or VR8305| 98720| 98720| 98720| 98720

396221 for single- stage valve VR8215| 260605| 260605| 260605| 260605| —

396021 for two- stage valve VR8105, VR8205, or VR8305| —| 197207| 197207|

197207
Air restrictor plate| 1-3/16-inch (30 mm) opening| 203078| —| —| —| —
1-3/8-inch (35 mm) opening| —| 196687
1-9/16-inch (40 mm) opening| —| 202051| —
1-3/4-inch (44 mm) opening| —| 196688| 196688
Table 5.  LP to NG Kit-Specific Components for UBX, UBZ, UDX, and UDZ Models

Component| Description| Gas Valve (Honeywell Model No.)
1/2-Inch, Single- tage (VR8105K2959, VR8205K2965, or VR8215T5214)| 1/2-Inch, Single-Stage (VR85K2959, VR8205K2965, or VR8215T5214) or
1/2-Inch, Two-Stage (VR8105N2931 or VR8205N2913)| 1/2-Inch, Single-Stage (VR85K2959,
VR8205K2965, or  VR8215T5214),
3/4-Inch Single-Stage
(VR8305N4258),
1/2-Inch, Two-Stage (VR8105N2931 or  VR8205N2913), or
3/4-Inch, Two-Stage (VR8305N4289)| 3/4-Inch Single-Stage
(VR8305N4258)
or 3/4-Inch, Two- Stage (VR8305N4289)
Unit Size (MBTUh)
30, 45| 60, 75| 100, 125| 150, 175| 200, 225, 250| 300, 350, 400
Kit PN
1036544R| 1036545R| 1036546R| 1036547R| 1036548R| 1036549R
Component PN
Spring kit| #394588 for single-stage valve VR8105, VR8205, or VR8305| 98721| 98721| 98721

396222 for single-stage valve VR8215| 261651| 261651| 261651| —

396205 for two-stage valve VR8105, VR8205, or VR8305| —| 197208| 197208|

197208
Table 6.  NG to LP Kit-Specific Components for UDAP, UDAS, UDBP, and UDBS Models

Component| Description| Gas Valve (Honeywell Model No.)
1/2-Inch, Single-Stage (VR8105K2942, VR8205K2957, or
VR8215T1239)| 1/2-Inch, Single-Stage (VR8105K2942, VR8205K2957, or VR8215T1239) or
1/2-Inch, Two-Stage (VR8105N2949 or VR8205N2921)| 1/2-Inch, Single-Stage (VR8205K2957 or VR8215T1239) or
1/2-Inch, Two-Stage (VR8205N2921)| 1/2-Inch, Single- Stage
(VR8205K2957 or VR8215T1239),
3/4-Inch Single- Stage
(VR8305K4241), or  1/2-Inch, Two-Stage (VR8205N2921 or
VR8305N4297)| 3/4-Inch Single- Stage
(VR8305K4241) or 3/4-Inch, Two-Stage  (VR8305N4297)
Unit Size (MBTUh)
30, 45| 60, 75| 100, 125| 150, 175| 200, 225, 250| 300, 350, 400
Model
UDAP,| UDBP,| UDAP,| UDBP,| All
UDAS| UDBS| UDAS| UDBS
Kit PN
1036536R| 1036541R| 1036537R| 1036542R| 1036538R| 1036539R| 1036540R| 1036543R
Component PN
Spring kit| #393691 for single- stage valve VR8105, VR8205, or VR8305| 98720| 98720| 98720| 98720

396221 for single- stage valve VR8215| 260605| 260605| 260605| 260605| —

396021 for two- stage valve VR8105, VR8205, or VR8305| —| 197207| 197207|

197207
Air restrictor plate| 1-3/8-inch (35 mm) opening| 196687| —| —| —| —
1-3/16-inch (30 mm) opening| —| 203078
1-3/4-inch (44 mm) opening| —| 196688| —| 196688
1-9/16-inch (40 mm) opening| —| 202051| —
The plate from kit PN 1036538R is not used on unit size 125 models. The plate from kit PN 1036539R is not used on unit size 175 models for residential or commercial applications.
Table 7.  LP to NG Kit-Specific Components for UDAP, UDAS, UDBP, and UDBS Models

Component| Description| Gas Valve (Honeywell Model No.)
1/2-Inch, Single- Stage (VR8105K2959, VR8205K2965, or VR8215T5214)| 1/2-Inch, Single-Stage (VR85K2959, VR8205K2965, or VR8215T5214)  or
1/2-Inch, Two-Stage (VR8105N2931 or  VR8205N2913)| 1/2-Inch, Single-Stage (VR85K2959, VR8205K2965, or VR8215T5214),
3/4-Inch Single-Stage
(VR8305N4258), 1/2-Inch,
Two-Stage (VR8105N2931
or
VR8205N2913),or 3/4-Inch, Two-Stage (VR8305N4289)| 3/4-Inch Single-Stage
(VR8305N4258)
or
3/4-Inch, Two-Stage  (VR8305N4289)
Unit Size (MBTUh)
30, 45| 60, 75| 100, 125| 150, 175| 200, 225, 250| 300, 350, 400
Kit PN
1036544R| 1036545R| 1036546R| 1036547R| 1036548R| 1036549R
Component PN
Spring kit| #394588 for single-stage valve VR8105, VR8205, or VR8305| 98721| 98721| 98721

396222 for single-stage valve VR8215| 261651| 261651| 261651| —

396205 for two-stage valve VR8105, VR8205, or VR8305| —| 197208| 197208|

197208

INSTALLATION

Install the conversion kit in accordance with the following steps. Ensure that the kit is correct for the size of the heater being serviced.

1. Remove gas supply and electrical power:
   a. Turn OFF gas supply at shutoff valve outside of heater.
   b. Turn OFF electrical power.
   c. Open control access panel.

2. Install regulator spring kit:
   ⚠ WARNING ⚠
   Regulator spring kits are not interchangeable. Each kit must be used only in the model and type of gas valve for which the kit is designated. Verify compatibility before installing the regulator spring kit.
   a. Select regulator spring kit that corresponds with gas valve on heater. All gas conversion kits include one or two regulator spring kits for single-stage valve and one regulator spring for two-stage valve. Other included regulator spring kits will not be used.
   b. Install regulator spring kit in accordance with gas valve manufacturer’s instructions (included with regulator spring kit).
   ⚠ CAUTION ⚠
   After a new regulator spring kit is installed, it is necessary to adjust the spring by adjusting the manifold pressure. This adjustment can be made only after the heater is in operation (refer to step 7).

3. Remove or install air restrictor plate as necessary and replace burner orifice:
   a. Carefully remove existing burner orifice (see Figure 2, DETAIL A).
   ⚠ DANGER ⚠
   • The air restrictor plate MUST BE INSTALLED when converting unit sizes 30, 45, 60, 75, 100, and 150 (all models) and unit size 125 (models UDBP, UDBS, UBX, UBXC, and UBZ) to propane.
   • The air restrictor plate MUST BE REMOVED when converting unit sizes 30, 45, 60, 75, 100, and 150 (all models) and unit size 125 (models UDBP, UDBS, UBX, UBXC, and UBZ) to natural gas.
   • For these models/unit sizes, the failure to install or remove the air restrictor plate in accordance with the following directions can cause death or injury and/or property damage.
   b. For unit sizes 30, 45, 60, 75, 100, and 150 (all models) and unit size 125 (models UDBP, UDBS, UBX, UBXC, and UBZ), proceed to step c. For all other models/unit sizes, proceed to step e.
   c. If converting from propane to natural gas, remove air restrictor plate as follows. If converting from natural gas to propane, install air restrictor plate in accordance with step d.
   (1) See Figure 2, DETAIL B to locate air restrictor plate held in place on venturi tube by its bent tabs.
   (2) Use pliers to carefully unbend tabs as shown in Figure 2, DETAIL A and remove air restrictor plate.
   d. For natural gas to propane conversion, install air restrictor plate as follows:
   (1) Refer to Table 4 or Table 6 to select correct air restrictor plate. Slide plate in place over venturi tube opening so that its 45-degree angle is hooked over rear of venturi tube (see Figure 2).
   (2) While holding plate in position, use pliers to carefully bend tabs to lock plate in place (see Figure 2, DETAIL
   B). Ensure that air restrictor is aligned and secure.
   e. For all conversions, select replacement burner orifices in accordance with Table 3. All conversion kits include two or three burner orifices. Other included orifice(s) will not be used.
   ⚠ WARNING ⚠
   Do not attempt to drill burner orifice. Use factory-supplied orifice only.
   f. Install replacement burner orifice (see Figure 2, DETAIL A).
   ⚠ CAUTION ⚠
   If the heater will be operated at an elevation >6,000 feet (>1,830 meters), a high-elevation pressure switch must be installed.
   NOTES:
   • If the installation elevation is >6,000 feet (>1,830 meters), verify that the elevation on the rating plate or high-elevation label is >6,000 feet (>1,830 meters). If the rating plate or label does not indicate an elevation of >6,000 feet (>1,830 meters), order  and install the appropriate high pressure switch kit.
   • If the heater is equipped for installation at an elevation of >6,000 feet (>1,830 meters) and is being installed at a lower elevation, order and install the appropriate switch.
   • Contact your distributor (refer to replacement parts manual) to select the factory-authorized replacement part.

4. For installations at elevations >6,000 feet (>1,830 meters), replace pressure switch in accordance with Pressure Switch Replacement section in installation/operation/maintenance manual provided with unit.

5. Restore electrical power and gas supply:
   a. Turn ON electrical power.
   b. Turn ON gas supply and relight heater, following instructions on heater.

6. Perform leak test:
   a. Check all connections for gas leaks using commercial leak-detecting fluid or rich soap and water solution.
   Leaks are indicated by presence of bubbles.
   b. If leak is detected, tighten connection. If leak cannot be stopped by tightening connection, replace part(s).
   NOTES:
   • Conversion of a unit using these kits does not alter the input rate. Refer to the rating plate on the heater for the input rate and other appropriate information.
   • If adjusted for high-elevation operation, the input rate will be affected.
   • The high-elevation adjustment label is not used on units operated at elevations of ≤2,000 feet (≤610 meters).

7. Adjust manifold (outlet) gas pressure in accordance with Measure and Adjust Manifold (Outlet) Gas Pressure section in installation/operation/maintenance manual provided with unit.

8. Close control access panel.

Specifications and illustrations subject to change without notice or incurring obligations.
Latest version of this manual is available at www.reznorhvac.com.
©2024 Nortek Global HVAC LLC, O’Fallon, MO. All rights reserved.
UB-UD-GC (01-24) 1034364-H

References

• Reznor HVAC

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