A traditional fireplace presence usually comes with tradeoffs: raised hearths, visible louvers, chimney requirements, or major framing work. The Monessen Lo-Rider Clean Face Vent-Free Gas Firebox is built specifically to eliminate those compromises.
Designed to sit low and install nearly flush with the floor, the Lo-Rider creates a grounded, masonry-style fireplace appearance that feels intentional rather than retrofitted. Its clean-face construction removes visual clutter from the opening, allowing the flame presentation and log set you choose to remain the focal point. Behind the scenes, the firebox geometry is engineered to move heat forward into the room using angled surfaces and controlled air channels rather than relying on exposed vents or bulky grilles.
This firebox is intended for homeowners and builders who want full design control. By pairing it with a compatible vent-free gas log set and optional interior panels, the Lo-Rider becomes a flexible foundation for both classic and modern fireplace installations, without the constraints of venting or a chimney chase.
Features
Vent-free gas firebox designed for clean, low-profile installations
Nearly floor-level installation for an authentic hearth-style appearance
Deep firebox accommodates a wide range of compatible vent-free gas log sets
Angled firebox construction improves heat movement into the living space
Engineered air channels help distribute warmth efficiently
Integrated mesh safety screen with concealed storage pockets
Interior liner options available to tailor the look of the firebox
Heavy-duty construction designed for long-term residential use
What’s Included
Firebox assembly – 1 set
Reversible liner – 1 set
User’s manual – 1
Optional fronts, lighting kits, reflective panels, fan kits, trim kits, and vent-free log sets are sold separately.
Specifications & Downloads
Overall Dimensions: 34" H x 48" W x 23" D
Framing Dimensions: 34 1/4" H x 48 1/2" W x 22 3/4" D
Viewing Area: 30" H x 42" W
Weight: 210 lbs
Installation Type: Vent-free gas firebox
Certification: UL Listed
Country of Origin: Made in the USA
Warranty: Limited Lifetime Warranty
This installation must conform with local codes. In the absence of local codes you must comply with the National Fuel Gas Code, ANSI Z223.1- latest edition in the U.S.A. and the CAN/ CGA B149 Installation codes in Canada.
This heater shall not be installed in a confined space or unusually tight construction unless provisions are provided for adequate combustion and ventilation air.
DO NOT INSTALL THIS MODEL IN A BEDROOM OR BATHROOM.
WARNING: This product and the fuels used to operate this product (liquid propane or natural gas), and the products of combustion of such fuels, can expose you to chemicals including benzene, which is known to the State of California to cause cancer and reproductive harm. For more information go to www.P65Warnings.ca.gov.
Frequently Asked Questions
Does this include a gas log set or burner?
No, this is the firebox shell only. It ships with the firebox assembly, a reversible liner, and the manual. You pair it with a compatible Monessen vent-free log set, sold separately, to complete the fireplace.
What rough opening do I need to frame for the 42" Lo-Rider?
Frame to 34-1/4" H x 48-1/2" W x 22-3/4" D, per the manufacturer's framing dimensions, slightly larger than the 34" x 48" x 23" overall unit to leave clearance.
What's the difference between the four brick liner options?
They're purely aesthetic interior liner finishes: concrete gray stacked, brown traditional, gray stacked, or gray herringbone. All four fit the same firebox and don't change the dimensions or performance.
Can this be installed in a bedroom or bathroom?
No. Like all vent-free gas appliances, Monessen prohibits installation in bedrooms or bathrooms per the installation manual.
Does this need a chimney or exterior vent?
No, it's a vent-free firebox that draws combustion air from the room and burns without external venting, which is what allows the low, flush-hearth installation.
What warranty comes with this firebox?
Monessen backs the firebox itself with a limited lifetime warranty. Since the log set and burner are purchased separately, check that product's own warranty card for its specific coverage terms.
