Best Uniflame Gas Fireplace of 2026 for Supplemental Heat

The Duluth Forge FDI32R is a ventless dual-fuel gas fireplace insert designed for homeowners who want supplemental heat without the architectural expense of a traditional chimney or exterior ductwork. Engineered as a zero-clearance firebox, this unit fits into recessed wall cavities, custom fireplace surrounds, or existing masonry hearth openings that have access to a gas supply line. It offers a practical option for homeowners seeking to upgrade an unused hearth or introduce an efficient focal point to a primary living area.

Heating capability is powered by a dual-fuel burner that can be hooked up to either natural gas or liquid propane. The unit delivers up to 32,000 BTUs of heat, which the manufacturer states can warm spaces up to 1,500 square feet at 99.9 percent efficiency. Ignition is managed through a push-button piezo system tied to a standing pilot light. An included handheld remote control with an LCD screen allows you to cycle the burner on and off from across the room, while flame height adjustments are made manually via the lower control valve.

In terms of visual design, the firebox is built with a black chassis measuring 36.38 inches wide, 33.27 inches high, and 18.38 inches deep, weighing in at 88.2 pounds. The interior display features nine hand-painted ceramic fiber logs arranged across an iron grate to emulate a traditional split-wood fire. A fixed black mesh screen covers the front opening, protecting the combustion area while allowing radiant and convective warmth to circulate freely into the room.

Proper installation requires careful attention to framing dimensions and structural clearances. Because this model utilizes a zero-clearance firebox, it can be framed directly into drywall or woodwork, but the manufacturer strictly requires at least 42 inches of clearance between the top of the insert and the ceiling. Since unvented appliances release warmth and combustion moisture directly into living spaces, homeowners must verify local building codes to ensure vent-free gas appliances are permitted in the intended room size and home location.

While this insert delivers robust supplemental heat and broad fuel compatibility, buyers should consider its operational characteristics. The remote operates strictly on an on/off basis without variable thermostat or flame modulation functions. For homes with compatible space, approved local codes, and access to a professional gas installer, the Duluth Forge FDI32R stands as a capable, low-maintenance heating solution that combines realistic hearth aesthetics with dependable heat output.

The zero-clearance firebox design of the Duluth Forge FDI32R allows it to be installed against or recessed into standard interior walls, custom wood mantels, or masonry openings, provided a dedicated gas line is routed to the site. Combustible materials must adhere to specific manufacturer guidelines, including maintaining a minimum clearance of 42 inches from the top of the firebox to the room ceiling.

Because this model operates without an external vent, chimney, or exhaust pipe, all combustion byproducts remain indoors. Buyers must check local and state building codes prior to purchase, as some jurisdictions restrict or prohibit vent-free gas appliances in bedrooms or enclosed spaces. Installation by a certified gas professional is recommended to confirm correct supply line sizing, check for gas leaks, and verify appropriate room air volume.

This insert utilizes patented dual-fuel technology, allowing it to function on either natural gas or liquid propane without requiring an aftermarket conversion kit. When switching between fuels, the gas connection must be configured according to manufacturer specifications to ensure correct burner pressure and safe operation.

The appliance utilizes a standard piezo push-button ignition to light the standing pilot. Once the pilot is active, the included LCD remote control can turn the burner on or off on demand. Fine-tuning the flame height is managed manually through the control knob located on the firebox face, giving users direct control over output and fuel usage.

The Duluth Forge FLF300T is a zero-clearance, ventless fireplace insert engineered to run exclusively on liquid propane. Designed for homeowners seeking an efficient supplemental heating option, this unit is well-suited for living rooms, family spaces, or open floor plans where ductwork or masonry chimneys are absent. Because it does not vent combustion air to the outdoors, it retains heat inside the living area while fitting cleanly into a framed wall opening or a compatible mantel cabinet.

According to manufacturer specifications, the unit generates up to 26,000 BTUs of heat, which Duluth Forge rates for areas up to 1,350 square feet. It operates at an advertised 99.9 percent efficiency. The insert relies on an integrated thermostatic control that monitors ambient temperature and cycles the burner on and off to maintain consistent warmth. A battery-assisted Piezo ignition system allows for straightforward lighting without relying on household electrical power, maintaining utility during standard electrical grid outages.

For visual presentation, the insert includes a dual precision ported burner coupled with five hand-painted ceramic fiber logs. These logs sit within the 47.6-pound firebox, providing the appearance of a traditional fire without producing ash or requiring chimney sweeping. The exterior dimensions measure 29.1 inches wide, 13.9 inches deep, and 23.9 inches high, giving it a balanced profile suited for standard fireplace openings or custom framing structures.

Installing a ventless propane appliance demands careful attention to clearances and fuel connections. As a zero-clearance appliance, it can be framed into combustible walls following manufacturer guidelines, but it requires a dedicated, regulated liquid propane line. For safety, the FLF300T incorporates an Oxygen Depletion Sensor (ODS) that automatically shuts off the gas supply if room oxygen drops below safe levels. Prospective buyers must confirm local building codes before purchase, as vent-free gas heaters are restricted or prohibited in select states, municipalities, and specific room types such as bedrooms.

The Duluth Forge FLF300T offers a capable heating solution for properties already equipped with propane service that need supplemental zone warmth. Buyers should verify their room cubic volume, existing propane gas line pressure, and regional code compliance prior to purchasing. When installed with proper clearances and maintained according to the manufacturer manual, this insert provides reliable warmth and realistic log ambiance without extensive chimney construction.

The Duluth Forge FLF300T features a zero-clearance firebox, allowing it to be recessed directly into wall framing or installed inside an approved fireplace mantel surround. Measuring 29.1 inches wide, 13.9 inches deep, and 23.9 inches high, buyers should carefully measure rough framing openings and maintain all manufacturer-specified clearance distances to combustible materials.

This appliance requires a dedicated liquid propane supply line with proper gas pressure regulators. Because installation involves pressurized gas connections and adherence to safety clearances, consulting a licensed gas technician and checking local municipality permits is strongly recommended.

Operating the FLF300T is managed through a built-in thermostatic control valve. The user sets a desired comfort level, and the internal thermostat automatically cycles the main burner on and off to regulate room temperature without continuous manual adjustments.

Starting the appliance utilizes a battery-assisted Piezo ignition system, which generates a reliable spark for the pilot flame. Because this ignition and control setup does not require standard 120-volt household electricity, the insert remains fully functional for heat during standard electrical power outages.