1. Introduction
This manual provides essential information for the proper installation, operation, and maintenance of your Viefow 4021-732 Natural Gas Pilot Assembly. This component is a replacement part designed for specific natural gas (NG) fireplaces from Heatilator, Heat-N-Glo, and Quadrafire. It is crucial to read and understand all instructions before proceeding with installation or use.
The pilot assembly is a critical safety and ignition component for standing pilot fireplace units. It includes a thermopile, thermocouple, sparker electrode, and tubing, all integrated into a single bracket for reliable performance.
2. Important Safety Information
- Natural Gas (NG) Only: This pilot assembly is designed exclusively for natural gas fireplaces and inserts. It cannot be used with LP (Liquid Propane) gas fireplaces or stoves. Using it with LP gas can result in serious injury or property damage.
- Standing Pilot Units Only: This assembly is for standing pilot units and does not work with SIT valves. Verify your fireplace type before installation.
- Professional Installation Recommended: Installation of gas components should ideally be performed by a qualified service technician. Improper installation can lead to gas leaks, fire, or explosion.
- Gas Leak Prevention: Do not bend the pilot tubing or other gas lines excessively during installation. Excessive bending can rupture the pipe and cause a gas leak. Always check for gas leaks after installation using a soap solution.
- Ventilation: Ensure adequate ventilation during and after installation.
- Power Disconnection: Always disconnect power to the fireplace unit before attempting any installation or maintenance.
3. Package Contents
Your Viefow 4021-732 Natural Gas Pilot Assembly package includes the following components:
- Pilot Assembly Bracket
- Thermopile (36 inches)
- Thermocouple (24 inches)
- Sparker Electrode (Ignitor Wire, 24 inches)
- Pilot Tubing (24 inches)
Image 3.1: The Viefow 4021-732 Natural Gas Pilot Assembly with its key components clearly labeled, including the 24-inch thermocouple, 24-inch ignitor wire, 36-inch thermopile, and 24-inch pilot tube. The assembly is mounted on a metal bracket.
4. Compatible Fireplace Models
The Viefow 4021-732 Pilot Assembly is a direct replacement for part numbers 4021-732, 25660, SRV4021-732, 25174, and SRV25174. It is compatible with a wide range of Heatilator, Heat-N-Glo, and Quadrafire natural gas fireplace models. Please verify your fireplace model number against the lists below:
Heatilator Fireplace Models:
- CD4236R & CD4236LR (Pre serial # GA1563745)
- CD4842R & CD4842LR (Pre serial # GA1563745)
- CGC150 & CGC150L (After date code 39/95)
- G141 & G141L
- G270M & G270LM
- GB4336 & GB4336L
- GB4942 & GB4942L
- GBCL36 (Pre serial # GA1549727)
- GBCR36 (Pre serial # GA1549727)
- GBFL36 (Pre serial # GA1549727)
- GBiS36 & GBIS36L
- GBST36 & GBST36L (Pre serial # GA1549727)
- GDCH36 & GDCH36L
- GDCH60 & GDCH60L (Pre serial # GA1540727)
- GDCH60V & GDCH60LV
- GDCL36 & GDCL36L
- GDCL60 & GDCL60L (Pre serial # GA1549727)
- GDCR36 & GDCR36L
- GDCR60 & GDCR60L (Pre serial # GA1548727)
- GDFL36 & GDFL36L
- GDFL60 & GDFL60L (Pre serial # GA1548727)
- GDFL60V & GDFL60LV
- GDST36 & GDST36L
- GDST60 & GDST60L (Pre serial # GA1548727)
- GDST60V, GDST60LV
- GC150 & GC150L (After date code 39/95)
- GCBC36 & GCBC36L
- GCBC42 & GCBC42L
- GCBC60 & GCBC60L
- GCBC80 & GCBC80L
- GCDC36 & GCDC36L
- GCDC42 & GCDC42L
- GCDC60 & GCDC60F
- GCDC80 & GCDC80L
- GGBR60 & GGBR60L
- GGBR80 & GGBR80L
- GNBC30 & GNBC30L
- GNBC33 & GNBC33L
- GNBC36 & GNBC36L
- GNBR30 & GNBR30L
- GNBR33 & GNBR33L
- GNBR36 & GNBR36L
- GNDC30 & GNDC30L
- GNDC33 & GNDC33
- GNDC36 & GNDC36L
- GNDH30 & GNDH30L
- GNDH33 & GNDH33L
- GNDH36 & GNDH36L
- GNDR30 & GNDR30L
- GNDR33 & GNDR33L
- GNDR36 & GNDR36L
- GNRC33 & GNRC33L
- GNRC36 & GNRC36L (Pre date code 18/02)
- GNRH33 & GNRH33L
- GNRH36 & GNRH36L
- GNTC50 & GNTC50B (Pre serial # GA1542189)
- GNTC80 & GNTC80B
Heat-N-Glo Fireplace Models:
- R-CAST
Quadrafire Fireplace Models:
- DV750 (POST SN 3196)
- DV425, DV425L
- SAPPHIRE 50 (DV450)
- DV-750, DV-450, DV-425
- DV400S, DV-400, DV400, DV400L
- Twilight II-B
- DV750 (PRE SN 3096)
Image 4.1: A visual representation of the compatibility information, listing various Heatilator, Quadrafire, and Heat-N-Glo fireplace models that are compatible with the Viefow 4021-732 Natural Gas Pilot Assembly.
5. Product Specifications
| Brand | Viefow |
| Model Name | Natural Gas Pilot Assembly |
| Item Model Number | 4021-732 |
| Power Source | Fuel Powered (Natural Gas) |
| Product Dimensions | 10"D x 1.2"W x 1.2"H (Approximate) |
| Material | Metal |
| Finish Type | Polished |
| Installation Type | Built-in |
| Special Feature | Safety Shut Off |
| Ventilation Type | Direct Vent (for compatible fireplaces) |
| Included Components | Thermopile, Thermocouple, Pilot Tubing, Sparker Electrode |
| Specific Uses For Product | Indoor Fireplaces |
| Item Weight | 0.21 Kilograms (7.4 ounces) |
6. Installation Instructions
Warning: Ensure the gas supply to the fireplace is turned off and the unit is cool before beginning installation. It is highly recommended that installation be performed by a qualified technician.
- Access the Pilot Assembly: Carefully open the fireplace access panel or remove logs/embers as necessary to gain clear access to the existing pilot assembly.
- Disconnect Old Assembly:
- Disconnect the gas pilot tube from the gas valve.
- Disconnect the thermocouple and thermopile wires from the gas valve or control board.
- Disconnect the ignitor wire from the ignitor module.
- Remove Old Assembly: Unfasten the mounting bracket of the old pilot assembly from its position near the burner. Carefully remove the entire old assembly.
- Inspect New Assembly: Before installing, visually inspect the new Viefow 4021-732 pilot assembly for any signs of damage. Ensure all components (thermopile, thermocouple, sparker electrode, pilot tubing) are securely attached to the bracket.
- Mount New Assembly: Position the new pilot assembly in the same location as the old one. Secure the mounting bracket firmly. Ensure the pilot hood is correctly oriented towards the main burner for proper ignition.
- Connect Components:
- Connect the pilot tubing to the gas valve. Ensure a tight, leak-free connection. Do not over-tighten or bend the tubing excessively.
- Connect the thermocouple and thermopile wires to their respective terminals on the gas valve or control board. Refer to your fireplace's specific wiring diagram if unsure.
- Connect the ignitor wire to the ignitor module.
- Check for Gas Leaks: After all connections are made, slowly turn on the gas supply to the fireplace. Apply a soap and water solution to all gas connections. If bubbles appear, a leak is present. Turn off the gas immediately, tighten the connection, and re-test. Repeat until no bubbles are observed.
- Test Ignition: Follow the operating instructions for your fireplace to light the pilot. Observe the pilot flame to ensure it is stable and engulfs the thermocouple and thermopile tips.
- Reassemble Fireplace: Once proper operation is confirmed, replace any removed logs, embers, and access panels.
Image 6.1: A complete view of the Viefow 4021-732 Natural Gas Pilot Assembly, showing the integrated bracket, pilot hood, electrode, thermocouple, thermopile, and associated tubing and wiring. This image provides a reference for the overall structure during installation.
Image 6.2: A detailed close-up of the pilot assembly's critical components: the thermocouple, electrode, pilot hood, and thermopile. This view is helpful for understanding the function and correct positioning of each part during installation and ensuring the pilot flame properly heats them.
Image 6.3: This image shows a fireplace with an important safety note: "NOTE: For Standing Pilot Units Only, Doesn't Work with SIT Valve. Do not bend the pipe excessively during installation, so as not to rupture and cause gas leakage." This reinforces critical installation warnings.
7. Operation
The Viefow 4021-732 Pilot Assembly is a replacement component for your fireplace's existing pilot system. Its operation is integrated with your fireplace's main control valve and ignition system. Once installed, the pilot assembly functions as follows:
- Pilot Ignition: When the fireplace is turned on, the ignitor electrode creates a spark to ignite the natural gas flowing from the pilot hood.
- Flame Sensing: The thermocouple, heated by the pilot flame, generates a small electrical current that signals the gas valve to remain open, ensuring the pilot stays lit.
- Safety Shut-off: The thermopile, also heated by the pilot flame, generates a larger electrical current to power the main gas valve. If the pilot flame extinguishes, the thermocouple and thermopile cool down, causing the gas valve to close, thus shutting off the gas supply for safety.
For detailed instructions on lighting your fireplace's pilot or operating the main burner, please refer to your specific fireplace model's user manual.
8. Maintenance
Regular maintenance helps ensure the safe and efficient operation of your pilot assembly and fireplace.
- Annual Inspection: It is recommended to have your fireplace and pilot assembly inspected annually by a qualified service technician.
- Pilot Flame Check: Periodically observe the pilot flame. It should be a strong, steady blue flame that fully engulfs the tips of the thermocouple and thermopile. A weak, yellow, or wavering flame may indicate a problem.
- Cleaning: Ensure the pilot hood and surrounding area are free from dust, debris, or soot buildup, which can obstruct the pilot flame or spark. Use a soft brush or compressed air for cleaning, ensuring the gas supply is off and the unit is cool.
- Component Integrity: Visually inspect the pilot tubing, thermocouple, thermopile, and ignitor wire for any signs of damage, corrosion, or loose connections.
9. Troubleshooting
If you encounter issues with your pilot assembly, consider the following common troubleshooting steps. Always ensure the gas supply is on and all connections are secure before troubleshooting.
- Pilot Will Not Light:
- No Spark: Check the ignitor wire connection. Ensure the ignitor electrode is clean and properly positioned to create a spark at the pilot hood.
- No Gas Flow: Verify the main gas supply valve to the fireplace is open. Check for any kinks or obstructions in the pilot tubing.
- Weak Spark: The ignitor module may be faulty or the ignitor wire connection loose.
- Pilot Lights but Will Not Stay Lit:
- Thermocouple Issue: The thermocouple may not be properly heated by the pilot flame, or it could be faulty. Ensure the pilot flame is strong and directly impinges on the thermocouple tip. Check its connection to the gas valve.
- Gas Valve Malfunction: In rare cases, the gas valve itself may be faulty and not holding the pilot open.
- Pilot Lights but Main Burner Will Not Ignite:
- Thermopile Issue: The thermopile may not be generating enough voltage to open the main gas valve. Ensure the pilot flame is strong and fully engulfs the thermopile tip. Check its connection.
- Main Gas Valve Issue: The main section of the gas valve may be faulty.
If these steps do not resolve the issue, contact a qualified service technician for further diagnosis and repair.
10. Warranty and Support
This Viefow pilot assembly comes with a Limited Warranty. For specific details regarding the warranty period and coverage, please refer to the product packaging or contact Viefow customer support directly.
For technical assistance, troubleshooting beyond this manual, or warranty claims, please contact Viefow customer service through the retailer where the product was purchased or visit the official Viefow website for contact information.