American Hearth VFSV Series
American Hearth VFSV Vent-Free Slope Glaze Variable Gas Burner – 16", 18", 24" & 30"
The American Hearth VFSV Vent-Free Slope Glaze Gas Burner is a variable-output gas burner system designed for approved vent-free installations and compatible solid-fuel-burning fireplaces. Available in 16-inch, 18-inch, 24-inch, and 30-inch sizes for either Natural Gas or Propane, the VFSV series delivers adjustable heat input from approximately 17,000 to 38,000 BTU, depending on model and fuel type.
Available Sizes 16", 18", 24" & 30"
Fuel Options Natural Gas or Propane
Heat Input 17,000–38,000 BTU
Valve Type Variable
Remote Control Included VFSV Remote
Flame Adjustment Four Flame-Height Levels
Installation Vent-Free or Vented
Configuration Burner Only
A Variable-Output Gas Burner for Flexible Fireplace Installations
The American Hearth VFSV is designed for homeowners who want the appearance of a traditional gas-log fire together with adjustable supplemental room heat. The burner can be installed as a vent-free heater where permitted or as a vented decorative appliance in an appropriate fireplace when installed according to the manufacturer's instructions.
Because an approved vent-free installation does not route normal combustion products up a chimney, more of the generated heat remains in the room than in a decorative vented installation. Adequate combustion and ventilation air must still be provided.
The VFSV series is available in four burner sizes with separate Natural Gas and Propane configurations. Each model has specific BTU ratings, gas-pressure requirements, fireplace dimensions, and installation requirements.
Quick buying rule: Choose the VFSV when you need a variable-output Natural Gas or Propane burner for an approved fireplace or vent-free firebox and want remote ON/OFF and flame-height adjustment. Verify fireplace dimensions, fuel type, local code requirements, ventilation, and clearances before selecting a burner size.
Fuel-type limitation: The manufacturer states that the appliance is only for use with the gas type shown on its rating plate. Natural Gas and Propane versions are separate appliances and are not field-convertible from one fuel to the other.
American Hearth VFSV at a Glance
Brand
American Hearth / Empire Comfort Systems
Product Type
Slope Glaze gas burner
Configuration
Burner only
Available Sizes
16", 18", 24", and 30"
Fuel Options
Natural Gas or Propane (LP)
Heat Input Range
Approximately 17,000 to 38,000 BTU depending on model and fuel
Remote Control
Included VFSV remote with ON/OFF and four flame-height levels
Key Features and Benefits
Variable Heat Output
The VFSV valve allows flame output to be adjusted instead of operating at only one fixed firing rate. Depending on model, input ranges from approximately 17,000 BTU at minimum fire to as much as 38,000 BTU at maximum fire.
Remote Flame Control
The supplied VFSV remote provides ON/OFF control plus four flame-height settings: High, Medium High, Medium Low, and Low.
Vent-Free Heating Option
In an approved vent-free installation, the burner operates without relying on an open chimney for normal exhaust and can provide supplemental room heat where vent-free appliances are permitted.
Vented Decorative Option
The burner can also be installed as a vented decorative appliance in a qualifying solid-fuel-burning fireplace when the damper is secured partially open as required.
Natural Gas & Propane Models
Separate Natural Gas and Propane models allow the burner to be matched to the property's available fuel supply.
Four Burner Sizes
Choose from 16", 18", 24", and 30" models to match compatible fireplace and firebox dimensions.
Is the American Hearth VFSV Right for Your Fireplace?
Best For
- Homeowners seeking supplemental room heating from an approved gas-log installation
- Approved vent-free firebox installations
- Qualifying masonry fireplaces
- Qualifying UL 127 factory-built fireplaces
- Natural Gas or Propane applications
- Buyers who want remote ON/OFF operation
- Buyers who want variable flame-height adjustment
- Installations that meet the manufacturer's minimum fireplace dimensions and clearances
Do Not Choose This Burner If
- Your local codes prohibit vent-free gas heaters and you specifically need vent-free operation.
- Your fireplace does not meet the manufacturer's minimum dimensions or clearance requirements.
- You need to convert the burner from Natural Gas to Propane or vice versa after purchase.
- You need a direct-vent fireplace system.
- You intend to use the burner as an unvented heater in a bedroom or bathroom.
- Your factory-built fireplace specifically prohibits unvented gas logs.
Available VFSV Models & BTU Ratings
Select the burner according to both fireplace size and fuel type. Natural Gas and Propane versions are separate appliances and are not interchangeable.
| Burner Size |
Model |
Fuel |
Minimum Input |
Maximum Input |
| 16" |
VFSV16NAT |
Natural Gas |
18,000 BTU |
25,000 BTU |
| 16" |
VFSV16LP |
Propane |
17,000 BTU |
22,500 BTU |
| 18" |
VFSV18NAT |
Natural Gas |
21,000 BTU |
32,000 BTU |
| 18" |
VFSV18LP |
Propane |
21,000 BTU |
32,000 BTU |
| 24" |
VFSV24NAT |
Natural Gas |
24,000 BTU |
36,000 BTU |
| 24" |
VFSV24LP |
Propane |
24,000 BTU |
36,000 BTU |
| 30" |
VFSV30NAT |
Natural Gas |
27,000 BTU |
38,000 BTU |
| 30" |
VFSV30LP |
Propane |
27,000 BTU |
38,000 BTU |
Do not size by BTU alone: Do not choose the largest burner simply because it has the highest output. The fireplace opening must meet the manufacturer's minimum dimensions for the exact burner size.
Gas Pressure Specifications
| Specification |
Natural Gas VFSV |
Propane VFSV |
| Regulator Pressure Setting |
4.0" W.C. |
10.0" W.C. |
| Maximum Gas Inlet Pressure |
10.5" W.C. |
13.0" W.C. |
| Minimum Gas Inlet Pressure |
7.0" W.C. |
11.0" W.C. |
Gas-supply installation: Gas supply sizing, pressure testing, shutoff valves, and piping requirements must be verified by the installer and must comply with applicable codes. Never use an exposed flame to test gas connections for leaks.
Minimum Fireplace Dimensions
The manufacturer specifies minimum dimensions for solid-fuel-burning masonry fireplaces and qualifying UL 127 factory-built fireplaces. Confirm the orientation of dimensions A, B, C, and D using the manufacturer's installation diagram before selecting a burner.
| VFSV Model Size |
Dimension A |
Dimension B |
Dimension C |
Dimension D |
| 16" |
18" |
11 1/2" |
24" |
18" |
| 18" |
17" |
14" |
28" |
17" |
| 24" |
23" |
14" |
30" |
18" |
| 30" |
26" |
14" |
34" |
20" |
The A/B/C/D labels above follow the manufacturer's fireplace-sizing diagram. Refer to the official manual when measuring so each dimension is matched to the correct part of the fireplace opening.
Installation Requirements
Proper installation is critical to safe operation, combustion performance, and flame appearance. The manufacturer states that installation and service must be performed by a qualified installer, service agency, or gas supplier.
Approved Installation Locations
- Solid-fuel-burning masonry fireplace
- Qualifying UL 127 factory-built fireplace
- Listed ventless firebox enclosure
Do Not Install If
- The factory-built fireplace prohibits unvented gas logs.
- The fireplace opening is smaller than the required dimensions.
- Required combustible clearances cannot be achieved.
- Required combustion and ventilation air cannot be provided.
Existing wood-burning fireplace preparation: Before installation, the firebox and chimney must be cleaned of soot, creosote, ashes, and loose paint. Fresh-air vents or ash clean-out doors that can create undesirable drafts must be addressed according to the manufacturer's instructions.
Professional installation required: Installation, gas connection, pressure verification, leak testing, servicing, and applicable fireplace modifications must be completed according to the manufacturer instructions and applicable codes.
Vent-Free vs. Vented Installation
Vent-Free Heating Configuration
In vent-free operation, the burner uses combustion air from the room and does not rely on the chimney to exhaust normal combustion products.
Adequate combustion and ventilation air must be available. This configuration is intended for supplemental room heating and may only be used where vent-free appliances are permitted.
Vented Decorative Configuration
The VFSV can also be installed as a vented decorative appliance in a qualifying solid-fuel-burning fireplace.
The flue must remain open, and the manufacturer-specified damper clamp is used to prevent the fireplace damper from accidentally closing.
Canada installation limitation: The manufacturer's manual states that the unit cannot be installed as an unvented appliance in Canada. Canadian installations are limited to the vented application and must follow the applicable Canadian installation requirements.
Combustion & Ventilation Air Requirements
Vent-free gas heaters consume oxygen from the room in which they operate. The VFSV therefore requires adequate combustion and ventilation air before it can be operated as an unvented heater.
The manufacturer specifically warns against operating the appliance in a confined space unless the necessary provisions for combustion and ventilation air have been provided.
Homes with unusually tight construction can also require additional fresh air. Follow local requirements and the combustion-air provisions specified in the manufacturer's installation instructions.
Carbon monoxide warning: Inadequate combustion or ventilation air can create a hazardous condition. The appliance incorporates an oxygen-depletion-sensor pilot safety system, but that system must never be bypassed, altered, or treated as a substitute for proper ventilation and installation.
Key Fireplace Clearance Requirements
- The sides of the fireplace opening must be at least 6" from a combustible wall.
- For the 16" model, the ceiling must be at least 36" from the fireplace opening.
- For 18", 24", and 30" models, the ceiling must be at least 41" from the fireplace opening.
- Without a hood, non-combustible material must extend at least 12" above the fireplace opening.
- With the optional hood arrangement described by the manufacturer, non-combustible material must extend at least 8" above the opening.
- If installed at floor level, the manufacturer specifies a 0" minimum floor clearance to combustibles.
- Glass fireplace doors must remain open whenever the log set is operating.
Mantel requirements vary: Mantel projection and height requirements depend on the installation. Do not rely only on summary dimensions; verify the exact mantel-clearance diagram in the manufacturer's manual.
VFSV Variable Remote Control
The VFSV remote-control system allows the appliance to be operated without reaching into the fireplace and provides both ON/OFF control and flame-height adjustment.
ON/OFF Control
Turns the appliance on or off when the receiver is placed in the REMOTE position.
Four Flame Levels
The HI/LOW control adjusts the burner through High, Medium High, Medium Low, and Low flame settings.
The transmitter uses a 12V A23 battery, while the receiver uses four AA batteries. The receiver must be positioned where its ambient temperature does not exceed 130°F.
Electrical warning: The VFSV receiver must never be connected directly to 110–120 VAC power. Follow the manufacturer wiring instructions exactly.
What's Included
| VFSV Slope Glaze Burner |
One American Hearth burner in the selected size and fuel configuration |
| Variable Remote Control System |
Provides ON/OFF operation and four flame-height settings |
| Damper Clamp |
Used for installations requiring the fireplace damper to remain secured open |
| Decorative Logs |
Do not assume included; this product is identified as a burner-only listing |
| Additional Accessories |
Do not assume included unless specifically listed with the selected configuration |
Burner-only listing: Do not assume decorative logs, additional accessories, or installation components are included unless they are specifically identified with the exact configuration being purchased.
Fireplace & Fuel Compatibility
Compatible Applications
- Listed ventless firebox enclosure
- Solid-fuel-burning masonry fireplace
- Qualifying UL 127 factory-built fireplace
- Natural Gas supply when purchasing a NAT model
- Propane supply when purchasing an LP model
Not Compatible With
- Fireplaces that prohibit unvented gas logs when used in vent-free mode
- The wrong fuel type
- Installations that fail minimum fireplace dimensions
- Installations that fail required combustible clearances
- Unvented applications in Canada
Do not convert the fuel type. Use only the Natural Gas or Propane version specified for the installation and shown on the appliance rating plate.
Flame Appearance & Ember Placement
After approximately 10 to 15 minutes of operation at full rate, the manufacturer describes normal flame appearance as sets of yellow flames. Flame movement and height naturally vary during operation.
Glowing ember material should be applied lightly. Excess ember material can produce an undesirable orange or stringy flame and can affect burner performance.
Ember material must not obstruct the large rear burner ports or the pilot assembly.
Decorative media placement: Lava rock belongs on the fireplace floor in front of the burner. Do not place lava rock on the burner, logs, or ember material.
VFSV Operating Overview
The VFSV uses a pilot that is lighted according to the manufacturer's lighting procedure. After the pilot remains stable, the gas control is placed in the operating position and the appliance can be controlled using the supplied remote.
Before lighting, always check the appliance area for gas odor, including near the floor.
If gas is detected: Do not attempt to light the appliance or operate electrical switches. Follow the manufacturer's gas-safety instructions and leave the area when directed.
Important Safety Information
- Do not install the appliance until adequate combustion and ventilation air has been provided.
- Do not use the appliance if any part has been under water.
- Keep gasoline and flammable vapors away from the fireplace.
- Keep clothing, furniture, draperies, and other combustibles away from hot surfaces.
- Children and adults must be alert to high surface temperatures.
- Young children require careful supervision while the appliance is operating.
- Do not allow fans to blow directly into the fireplace.
- Do not use unapproved blower inserts or heat-exchanger inserts.
- Operate the heater with the fireplace screen in place.
- Keep burner air openings clean.
- Do not burn wood or other solid fuels while the gas-log appliance is installed.
Qualified installation and service required: Improper installation, alteration, servicing, or operation can create fire, explosion, burn, or carbon-monoxide hazards.
Bedroom & Bathroom Installation Restrictions
The manufacturer's safety instructions state that an unvented room heater with an input above 6,000 BTU per hour must not be installed in a bathroom, while an unvented room heater above 10,000 BTU per hour must not be installed in a bedroom or bathroom.
Do not install a VFSV as an unvented heater in a bedroom or bathroom. Every VFSV model listed on this page exceeds 10,000 BTU input.
What to Expect During Initial Operation
During initial use, manufacturing oils, films, paint, and bonding agents can produce temporary odors or smoke while they cure.
The manufacturer recommends ventilating the room during the initial break-in period. The supplied information describes approximately 2 to 3 hours of initial operation at the highest setting with windows or doors opened for maximum ventilation.
Water Vapor From Vent-Free Operation
Water vapor is a normal by-product of gas combustion. The manufacturer states that an unvented room heater produces approximately 1 ounce / 30 ml of water for every 1,000 BTU of gas input per hour.
Consider room conditions: The moisture produced during vent-free combustion should be considered when deciding whether unvented operation is appropriate for the intended room and building conditions.
Cleaning & Maintenance
The manufacturer recommends annual inspection and cleaning by a dealer or qualified service technician to help prevent malfunction and sooting.
- Turn the heater off and allow it to cool before cleaning.
- Do not use cleaning fluid on the logs or heater components.
- Remove loose dust and particles from burner areas and controls.
- Clean the grate as required.
- Inspect and clean the burner air-intake opening.
- Keep burner ports free from lint and debris.
- Inspect the oxygen-depletion-sensor pilot for lint accumulation.
- Verify proper flame pattern and component placement.
- Verify smooth and responsive burner ignition.
Do not use needles, wires, or similar objects to clean the ODS pilot. They can damage the calibrated gas-flow component.
When to Stop Using the Burner and Request Service
Stop operating the appliance and have it inspected when abnormal combustion or gas-system behavior occurs.
- The pilot will not remain lit.
- The appliance repeatedly shuts down during operation.
- Gas odor is present.
- The burner produces soot after the initial curing period.
- A loud, roaring, blowtorch-like sound occurs at the main burner orifice.
- The burner will not ignite after the pilot is established.
- Flame appearance indicates incorrect pilot operation.
If gas is smelled: Do not operate electrical switches or attempt to light the appliance. Leave the area and follow the manufacturer's emergency gas instructions.
Flame Authority Expert Recommendation
The American Hearth VFSV is best suited to buyers who already have, or are planning, a qualifying fireplace or listed vent-free firebox and want a variable-output gas burner with convenient remote flame adjustment.
Its four size choices and separate Natural Gas and Propane configurations make it possible to match the burner to the fireplace rather than forcing one burner size into every application.
The most important buying decision is not simply maximum BTU output. First confirm the fireplace's internal dimensions, approved appliance type, available fuel supply, local vent-free regulations, combustion-air requirements, and required clearances. Once those conditions are satisfied, select the appropriate VFSV size and exact fuel-specific model.
Official Product Resource
Review the complete installation, operation, combustion-air, clearance, gas-supply, maintenance, and safety documentation before installing or operating the burner.
American Hearth VFSV Gas Burner FAQs
Is the American Hearth VFSV a vent-free gas burner?
Yes. The VFSV can operate as a vent-free heater where permitted, but the room and installation must meet the manufacturer's combustion-air, fireplace, clearance, and code requirements.
Can the VFSV burner also be installed as a vented gas log burner?
Yes. It can be installed as a vented decorative appliance in a qualifying solid-fuel-burning fireplace, but the damper must be secured open according to the manufacturer's instructions.
Can I install the VFSV in an existing wood-burning fireplace?
Yes, if the fireplace is a qualifying masonry or UL 127 factory-built fireplace and meets all sizing and installation requirements. Do not install it where the fireplace manufacturer prohibits unvented gas logs.
What sizes are available for the American Hearth VFSV burner?
The VFSV is available in 16", 18", 24", and 30" sizes. Only choose a size after confirming that the fireplace meets the manufacturer's minimum dimensions for that model.
What is the BTU range of the American Hearth VFSV?
Input ranges from 17,000 BTU on the 16" Propane model to 38,000 BTU on the 30" models. Exact minimum and maximum input depends on burner size and fuel type.
Does the American Hearth VFSV work with Natural Gas and Propane?
Separate Natural Gas and Propane models are available. Use only the fuel type shown on the appliance rating plate because the manufacturer states that the appliance is not convertible to another gas.
Does the VFSV include a remote control?
Yes. The supplied VFSV remote provides ON/OFF operation and four flame-height levels: High, Medium High, Medium Low, and Low.
Is the VFSV remote a thermostat?
The supplied VFSV instructions document ON/OFF and four-level flame-height control. Do not assume thermostat operation unless the exact control package explicitly supports it.
Does the VFSV use electronic intermittent ignition?
The manufacturer's VFSV instructions describe a pilot that is manually lighted using the piezo ignitor or approved lighting procedure. Do not confuse VFSV variable models with the separate VFSE intermittent models.
Does the VFSV burner include gas logs?
This product is identified as a burner-only listing. Do not assume logs are included unless they are explicitly listed with the selected configuration.
Can I install the VFSV in a bedroom?
No, not as an unvented heater. Every listed VFSV model exceeds the manufacturer's 10,000-BTU limit for unvented installation in bedrooms.
Can I install the VFSV in a bathroom?
No, not as an unvented heater. The manufacturer's instructions prohibit unvented room heaters above 6,000 BTU in bathrooms, and every VFSV model exceeds that rating.
Can the VFSV be used vent-free in Canada?
No. The manufacturer's Canadian requirements state that the appliance cannot be installed as an unvented appliance in Canada and must be installed in a vented application.
Do glass fireplace doors stay open while the VFSV is operating?
Yes. The manufacturer requires glass fireplace doors to remain open while the gas-log appliance is operating.
Does a vent-free VFSV need fresh air?
Yes. Vent-free operation uses room air for combustion and requires adequate combustion and ventilation air. Do not operate the heater in a space that cannot meet those requirements.
Does vent-free operation create moisture?
Yes. The manufacturer states that an unvented gas heater produces approximately one ounce of water vapor for every 1,000 BTU of gas input per hour.
How often should the VFSV burner be serviced?
The manufacturer recommends inspection and cleaning at least annually by a dealer or qualified service technician. More frequent cleaning is required when lint or debris accumulates.
Can I place lava rock directly on the VFSV burner?
No. Lava rock belongs on the fireplace floor in front of the burner and must not be placed on the burner, logs, or ember material.
Can I use a blower with the VFSV burner?
Do not use a blower insert, heat-exchanger insert, or accessory unless it is specifically approved for the heater. Fans must also not blow directly into the fireplace.
How do I choose between the 16", 18", 24", and 30" VFSV burners?
Measure the fireplace and compare it with the manufacturer's minimum dimensions before choosing a size. Do not select a larger burner solely for higher BTU output if the fireplace cannot accommodate it.
Before You Order
Confirm Before Purchase
- Exact fireplace dimensions
- Required VFSV burner size
- Natural Gas or Propane fuel supply
- Whether vent-free operation is permitted locally
- Combustion and ventilation-air requirements
- Required side, ceiling, mantel, and non-combustible clearances
- Compatible log set and accessories
Do Not Assume
- That the largest burner is automatically the best choice
- That Natural Gas and Propane models can be converted later
- That every fireplace permits vent-free gas logs
- That vent-free operation is permitted in every jurisdiction
- That decorative logs are included with the burner
- That the VFSV remote provides thermostat operation
Final specification check: Use the exact appliance rating plate and current manufacturer instructions as the final authority for model selection, fuel type, fireplace dimensions, clearances, gas pressure, installation configuration, and operation.
