A Monessen vent free firebox is the steel box your builder frames into an indoor wall and finishes in stone, tile or brick. It is sold without a burner, so you choose the fire and the finish separately. You may also see it called a Monessen ventless firebox, which is the same box. If you want to add a fireplace to your home in a new wall or a room that never had one, start with the opening size and the look you want.


What completes Monessen vent free fireboxes?

Monessen Hearth makes the box, and you complete it with a Monessen vent free log set or glass burner of your choice. Explore the brand’s logs and glass burner or browse gas fireplace burners. Your builder will install the metal shell before finishing the wall to suit your design. The logs set the heat and the flames.

Choose your opening and finish

The traditional styles come 32, 36 or 42 inches wide. Pick the size on the product page. One has a clean face with no vent slots and optional brick or reflective black glass interior panels. The other has a 27 inch tall opening and an angled back that moves more heat into the room. Both have screens that slide into side pockets.

The floor level style comes 36 or 42 inches wide, with a 30 inch tall opening for a wood fireplace look. The 36 inch see-through style shares a floor level fire between two rooms. Compare double sided fireplaces. For another layout, explore corner fireplaces.

No chimney, warmth in the room

A vent free system, sometimes called a ventless gas firebox, needs no chimney, no vent pipe and no liner. With this vent-free setup, nearly all the heat stays in the room. Choose fuel with the log set. Check your local code first because some areas restrict vent free fireplaces. Compare ventless gas fireplaces and indoor fireplace options.

A complete fireplace or a patio instead?

Prefer the parts together? Browse complete Monessen fireplaces with the burner and logs or glass included. For a patio wall, choose from the outdoor Monessen line.

Why buy from My Cozy Outdoors?

We are an authorized Monessen dealer, so the full manufacturer warranty applies. We match the firebox, logs and burner by phone before you order. Call us and we will talk it through, or browse the whole Monessen range.

Frequently asked questions

How does a vent free firebox work?

The steel box is framed and finished into the wall. Add a vent free log set or glass burner and connect gas. With no chimney or vent pipe, nearly all heat stays inside. Logs determine heat. Check local code first because some areas restrict vent free.

Do I need a firebox for ventless gas logs?

Not if your existing fireplace can take ventless gas logs. You need a firebox when building into a new wall or a room that never had a fireplace. Then you order the firebox and log set together. Call us and we will talk it through.

What makes the floor level Monessen firebox different from a standard one?

Its 30 inch tall opening sits flush with the floor for a wood fireplace look. Screens slide into side pockets. Choose 36 or 42 inches wide. A see-through version shares the floor level fire between two rooms. Traditional styles sit higher and offer three widths.

Are Monessen vent free fireboxes good quality?

A shopper on Reddit asked this about the 42 inch floor level firebox after reading some harsh online reviews. A dealer in the thread said they had put in a Monessen vent free fireplace for a customer months earlier and had heard no complaints. The same dealer explained that Monessen belongs to Hearth & Home Technologies, the parent of Majestic, and is the group's vent free brand, and that the maker gives support only through its dealers rather than a direct line, which is partly why reviews can read harshly. Another dealer called it a reliable firebox and the better looking one. We are an authorized dealer for every Monessen vent free firebox, so call us before or after you buy, and the full manufacturer warranty applies.