REZNOR CAUA Gas Conversion Kit

GENERAL INFORMATION

These gas conversion kits are for model CAUA heaters equipped with specific single-stage or two-stage gas valves. The kits are for operation at sea level. When converting a unit with a two-stage valve (option AG2), check for the valve manufacturer. If the unit has a two-stage White-Rodgers valve, a new two-stage gas valve is required.

Gas Valve Identification

In order to verify which conversion kit is compatible with your heater, it is necessary to know the type of gas valve on the heater. Refer to the unit rating plate for the complete model number of the heater. Also, refer to the manufacturer’s name and number found on the gas valve. Match the model number of the valve to the one listed in the kit—if different, contact your manufacturer representative to select and verify parts required for gas conversion.

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 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.

• 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.

• FOR YOUR SAFETY: Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.

• The gas burner in this gas-fired equipment is designed and equipped 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.

• If installed as a separated-combustion system, install either the horizontal or vertical combustion air/vent system illustrated in the heater installation manual, using the concentric adapter supplied. All installations must comply with the combustion air requirements in the installation codes and instructions. Units installed in a confined space must be supplied with air for combustion and ventilation as required by code and in the heater installation manual. 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 SYSTEM IN PROPERLY-OPERATING CONDITION.

CONVERSION KIT SELECTION

NOTES:

• Refer to Table 1 for a list of natural gas (NG) to propane (LP) conversion kit components.
• Refer to Table 2 for a list of propane to natural gas conversion kit components.
• Refer to Table 3 for burner orifices included in the gas conversion kits (for sea-level operation only) and for replacement orifices for high-elevation (>2,000 feet) installations.
• Refer to Table 4 for a list of additional components required for converting a unit equipped with a two-stage White-Rodgers (WR) gas valve. When converting a unit with a two-stage valve (option AG2), check for the valve manufacturer. If equipped with a Honeywell (HW) valve, select the kit listed in Table 1 and Table 2.
• All kits include the quantity of orifices required for the largest size of heater. Extra burner orifices may not be returned for credit.

Table 1. Natural Gas to Propane Conversion Kit Components

Table 1.  Natural Gas to Propane Conversion Kit Components

Unit Size

| Kit PN| Component ***| Description| PN**|

Gas Valve (Model No.

**** All

|

NG to LP spring kit

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

98720

| **** —

Tape

| Conversion| 64391
Disk| Propane|

37752

**** 150

| **** 269833| NG to LP spring kit| HW #396221 for single-stage valve VR8215| 260605| Single-stage (HW #VR8304M2816, #VR8205M1130, or #VR8215S1263)
or
two-stage (HW #VR8204Q2418)
Spring regulator kit|

HW #396021 for two-stage valve

|

197207

**** 200

|

**** 269834

|

NG to LP spring kit

| HW #396221 for single-stage valve VR8215|

260605

Spring regulator kit

|

HW #396021 for two-stage valve

|

197207

250

| 170815| Spring regulator kit| WR #F920659 for single-stage WR valve| 82524| **** Single-stage (WR #36C68-452, #36H32-441, or HW #VR8305M4009)
or
two-stage (HW #VR8304Q4404)

HW #396021 for two-stage valve

|

197207

275, 300

| 170816| Spring regulator kit| WR #F920659 for single-stage WR valve| 82524
HW #396021 for two-stage valve|

197207

350

| 170817| Spring regulator kit| WR #F920659 for single-stage WR valve| 82524
HW #396021 for two-stage valve|

197207

400|

170818

| Spring regulator kit| WR #F920659 for single-stage WR valve| 82524
HW #396021 for two-stage valve|

197207

*** Burner orifices are include in each kit. Refer to Table 3** for orifice PN, size, and quantity.

Table 2.  Propane to Natural Gas Conversion Kit Components

Unit Size

| Kit PN| Component ***| Description| PN**|

Gas Valve (Model No.

All

| LP to NG spring kit| HW #394588 for single-stage valve VR8105, VR8205, or VR8305| 98721| —
Tape|

Conversion

| 64391

Disk

| Natural Gas|

1401

**** 150|

269833

| LP to NG spring kit| HW #396222 for single-stage valve VR8215|

261651

|

Single-stage (HW #VR8204M1018, #VR8205M1148, or #VR8215S5215)
or
two-stage (HW #VR8304Q4412)

Spring conversion kit

| HW #396025 for two-stage valve|

197208

**** 200

| **** 269834| LP to NG spring kit| HW #396222 for single-stage valve VR8215| 261651
Spring conversion kit|

HW #396025 for two-stage valve

|

197208

250, 275, 300

| 170810| Spring conversion kit| WR #92-0656 for single-stage WR valve|

82525

|

**** Single-stage (WR #36C68-325, #36H32-442, or HW #VR8305M4819)
or
two-stage (HW #VR8304Q4412)

HW #396025 for two-stage valve

|

197208

350

| 170811| Spring conversion kit| WR #92-0656 for single-stage WR valve| 82525
HW #396025 for two-stage valve|

197208

400

| 170812| Spring conversion kit| WR #92-0656 for single-stage WR valve| 82525

HW #396025 for two-stage valve

|

197208

*** Burner orifices are include in each kit. Refer to Table 3** for orifice PN, size, and quantity.

Table 3.  Burner Orifices

Installation Elevation (Feet (Meters))

| Installation Location| Gas Type| Unit Size
150| 200| 250|

275

| 300| 350|

400

PN, Orifice Size (Quantity)

**** 0–2000 (0 –610)

| US or Canada| Natural| 164866, 2.10 mm (8)| 11833, #44 (10)| 11833, #44 (13)| 16590, #46 (15)| 11833, #44(15)| 11835, #37 (12)| 45870, #38m (14)
**** Propane| 97359, 1.25 mm (8)| 11830, #55 (10)| 97359, 1.25 mm (13)| 11830,  #55 (15)| 9789, #53 (12)|

61653, 1.55 mm (14)

**** 2001–3000 (611–915)

| US| Natural| 84853, #47 (8)| 38678, #45 (10)| 38678, #45 (13)| 84853, #47 (15)| 38678, #45 (15)| 45870, #38 (12)| 45871, #39 (14)
**** Propane| 97359, 1.25 mm (8)| 11830, #55 (10)| 97359, 1.25 mm (13)| 11830, #55 (15)| 11834, #54 (12)|

9789, #53 (14)

**** 2001–4500 (611–1373)

| Canada| Natural| 40414, #48 (8)| 38678, #45 (10)| 38678, #45 (13)| 38678, #45 (15)| 45871, #39 (12)| 11792, #41 (14)
**** Propane| 63003, 1.20 mm (8)| 11830, #55 (10)| 63003, 1.20 mm (13)| 11830, #55(15)| 11834, #54 (12)|

61652, 1.45 mm (14)

**** 3001–4000 (916–1220)

| US| Natural| 84853, #47 (8)| 38678, #45 (10)| 38678, #45 (13)| 84853, #47 (15)| 38678, #45 (15)| 45871, #39(12)| 87391, #40 (14)
**** Propane| 63003, 1.20 mm (8)| 11830, #55 (10)| 63003, 1.20 mm (13)| 11830, #55 (15)| 11834, #54 (12)|

9789, #53 (14)

**** 4001–5000 (1221–1525)

| US| Natural| 40414, #48 (8)| 38678, #45 (10)| 38678, #45 (13)| 84853, #47 (15)| 38678, #45 (15)| 45871, #39 (12)| 11792, #41 (14)
**** Propane| 63003, 1.20 mm (8)| 11830, #55 (10)| 63003, 1.20 mm(13)| 11830,

55 15)| 11834, #54 (12)|

61652, 1.45 mm (14)

**** 5001–6000 (1526–1830)

| US| Natural| 40414, #48 (8)| 16590, #46 (10)| 16590, #46 (13)| 40414, #48 (15)| 16590, #46 (15)| 87391, #40 (12)| 11792, #41 (14)
**** Propane| 63003, 1.20 mm (8)| 39658, #56 (10)| 63003, 1.20 mm (13)| 39658, #56 (15)| 11834, #54 (12)|

61652, 1.45 mm (14)

**** 6001–7000 (1831–2135)

| US| Natural| 40414, #48 (8)| 84583, #47 (10)| 84583, #47 (13)| 39651, #49 (15)| 84583, #47 (15| 11792, #41 (12)| 84437, #42 (14)
**** Propane| 39658,  #56(8)| 39658, #56 (10)| 39658, #56 (13)| 39658, #56 (15)| 11834, #54 (12)|

61652, 1.45 mm (14)

**** 7001–8000 (2136–2440)

| US| Natural| 39651, #49 (8)| 84583, #47 (10)| 84583, #47 (13)| 39652, #50 (15)| 84583, #47 (15)| 84437, #42 (12)| 84437, #42 (14)
**** Propane| 63922, 1.15 mm (8)| 39658, #56 (10)| 63922, 1.15 mm (13)| 39658, #56 (15)| 11834, #54 (12)|

11834, #54 (14)

**** 8001–9000 (2441–2745)

| US| Natural| 39651, #49 (8)| 40414, #48 (10)| 40414, #48 (13)| 39652, #50 (15)| 40414, #48 (15)| 84437, #42 (12)| 11828, #43 (14)
**** Propane| 63922, 1.15 mm (8)| 39658, #56 (10)| 63922, 1.15 mm (13)| 39658, #56 (15)| 11830, #55 (12)|

11834, #54 (14)

Table 4.  Components Required for Converting Unit with Two-Stage White- Rodgers Gas Valve

Unit Size

|

Two-Stage Gas Valve

|

Brass Plug

| Reducing Bushing (3/4- to 1/2-Inch) *****

Natural Gas

|

Propane

150|

177396

|

**** 177398

|

**** 107367

|

37385

200

250

|

**** 177397

|

**** —

275

300

350

400

***** Used only for natural gas to propane conversions.

INSTALLATION

Install the conversion kit in accordance with the following steps. Ensure that the kit (refer to Table 1 or Table 2) is correct for the size of the heater being serviced. Heater component locations are shown in Figure 1.

NOTE: Conversion using these kits will not alter the input rate. Refer to the rating plate on the unit for the input rate and other appropriate information.

1. Remove gas supply and electrical power:

2.  Turn OFF gas supply at shutoff valve upstream of combination gas valve.

3. Turn OFF electrical power.

4. Open control access panel.

5.  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.
   

6. 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.

7. I nstall regulator spring kit in accordance with gas valve manufacturer’s instructions (included with regulator spring kit).
   NOTE: Depending on when the unit was manufactured, there will be either two or three burner covers. If two, there will be right and left covers that extend over the front of the unit. If three, there will be right and left covers and a separate front cover.
   NOTE: When converting a unit with a two-stage White-Rodgers gas valve the spring kits in the conversion kit will not be used and the gas valve requires replacing.
   

8. For units with White-Rodgers two-stage gas valve, replace valve:

9. Disconnect gas valve wires from existing valve. Label wires for correct reconnection.

10. Disconnect existing gas valve from gas supply line and remove valve.
    NOTE: Because the unit does not have a pilot, the pilot port on the replacement two-stage White Rodgers gas valve needs to be plugged using a brass plug.

11. Using brass plug listed in Table 4, plug port labeled “pilot” on replacement valve listed in Table 4.
    WARNIG The operating gas valve is the primary safety shutoff. The gas supply line must be free of dirt or scale before connecting the valve.
    

12. Connect inlet side of replacement gas valve to gas supply line. Do not connect valve to manifold.

13. Connect gas valve wires labelled in step 3b to valve.

14. Ensure that all gas valve connections are in accordance with unit wiring diagram and valve manufacturer’s instructions.

15. Replace burner orifices:
    

16. Remove all burner covers and disconnect manifold from valve.

17. Remove screws that secure manifold assembly and remove manifold assembly from heater.

18. Carefully remove existing burner orifices.

19. For all conversions, select replacement burner orifices in accordance with Table 3.
    WARNING Do not attempt to drill burner orifice. Use factory-supplied orifice only.
    

20. Install replacement burner orifices.
    CAUTION Ensure that the manifold is positioned properly with relation to the burner rack.
    

21. Install manifold assembly in heater and secure using screws removed in step 4b.

22. Attach conversion disk to heater near gas valve .
    

23. Connect manifold to valve. For natural gas to propane conversion of unit size 150 or 200 with White-Rodgers two-stage gas valve, use reducing bushing listed in Table 4 to connect valve.

24. Install burner cover removed in step 4a.

25. Perform leak test:

26. Turn ON gas supply at shutoff valve upstream of combination gas valve.

27. Check between shutoff valve and combination gas valve for gas leaks using commercial leak-detecting fluid or rich soap and water solution. Leaks are indicated by presence of bubbles.

28. If leak is detected, tighten connection. If leak cannot be stopped by tightening connection, replace part(s).

29. When no leaks are detected, turn OFF gas supply at shutoff valve upstream of combination gas valve.

30. Restore electrical power and gas supply:

31. Turn ON electrical power.

32. Turn ON gas supply and relight heater in accordance with instructions on heater.

33. Recheck all manifold connections for gas leaks in accordance with step 5.

34. Measure and adjust manifold (outlet) pressure:
    WARNING  Manifold gas pressure must never exceed 3.5 IN WC for natural gas or 10 IN WC for propane.
    Incorrect inlet pressure could cause excessive manifold gas pressure.
    

35. Ensure that inlet (supply) pressure is in accordance with Table 5 and determine correct manifold (outlet) pressure (refer to Table 5).

36. Turn knob or switch on top of valve to OFF to prevent flow to gas valve.
    NOTE: A manometer (fluid-filled gauge) is recommended rather than a spring-type gauge due to the difficulty of maintaining the calibration of a spring-type gauge. Use a water column manometer that is readable to the nearest tenth of an inch.
    

37. Connect manometer to 1/8-inch output pressure tap on valve (see Figure 2).
    CAUTION DO NOT bottom out the gas valve regulator screw. This can result in excessive overfire and heat exchanger failure due to unregulated manifold pressure.
    

38. To measure/adjust high fire pressure on single-stage or two-stage valve:
    (1) Turn knob or switch on top of valve to ON.
    (2) If pressure is out-of-range, remove cap from regulator screw (see Figure 2) and adjust pressure in accordance with Table 5 by turning regulator screw IN (clockwise) to increase pressure or OUT (counterclockwise) to decrease pressure.

39. To measure/adjust low fire pressure on two-stage valve:
    (1) Disconnect wire from HI terminal on gas valve.
    (2) Remove cap from low-fire regulator screw (see Figure 2) and adjust pressure in accordance with Table 5 by turning regulator screw IN (clockwise) to increase pressure or OUT (counterclockwise) to decrease pressure.
    
    (3) Reconnect wire to Hi terminal on gas valve.
    WARNING  In the event of improper ignition, wait at least 5 minutes before attempting to relight the heater
    

40. Turn up thermostat and cycle burner once or twice to properly seat adjustment spring in valve.

41. Recheck outlet pressure. When pressure corresponds to Table 5, disconnect manometer and install cap on regulator screw.

42. Check for leakage at 1/8-inch outlet pressure tap fitting. Correct as necessary.

43. Operate heater for at least one complete cycle to check for proper operation. Observe main burners for complete flame carryover.

44. Fill out conversion tape and adhere to clean, dry surface near unit rating plate.

45. Close control access panel.

CUSTOMER SUPPORT

Specifications and illustrations subject to change without notice or incurring obligations. Latest version of this manual is available at www.reznorhvac.com.

©2023 Nortek Global HVAC LLC, O’Fallon, MO. All rights reserved.
CAUA-GC (04-23) 170635-C

Documents / Resources

| REZNOR CAUA Gas Conversion Kit [pdf] Installation Guide
CAUA, CAUA Gas Conversion Kit, CAUA Conversion Kit, Gas Conversion Kit, Gas Conversion, Conversion Kit
---|---

References

• Reznor HVAC

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