Gas fireplace venting by local pros in Florida Center

How a B-vent fireplace uses the air in your room

A natural-vent, or B-vent, fireplace burns air from the room and lets the warm exhaust rise through its own pipe by draft. The unit has a draft hood, and one maker requires that hood to sit in the same air pressure zone as the combustion air inlet.

The pipe must be Type B gas vent listed to UL 441, which the Florida fuel gas code requires in section 503.6.1. Our technicians confirm the pipe type from the markings on the sections they can reach, since the wrong vent type is one of the causes of poor draft listed in the manual.

Why a B-vent loses its draft

Poor draft has a long list of venting causes in one B-vent fireplace manual, and each one points at a different repair. Our pros work through it in order, since the fix for a short vent is nothing like the fix for a blocked one.

The list below comes from that manual. Several causes can exist on the same house, which is why we check them all before quoting.

• Too much offset or too many elbows
• A vent that is too short or too close to the roof line
• A blockage restricting the pipe
• The wrong vent type or the wrong size
• More than one appliance on one vent

Blue flames that float off the burner

Flames that turn blue, lift off the burner and wander are sometimes called ghosting. One direct-vent manual ties it to insufficient oxygen reaching the fire and lists four checks for it.

Our crew works through those checks in Florida Center before anything is replaced, starting with the easiest to reach.

• Cap installed correctly and free of debris
• Vent joints tight with no leaks
• No debris blocking the air intake at the back of the firebox
• Glass secured and latched

Moving the termination during a remodel

Relocating a vent cap counts as a new installation of the vent rather than a small extension. The new route has to fit the manual's vent graph, stay inside the elbow and length limits and end at a spot that meets every termination clearance.

Our specialists plan the route before the walls are opened in Florida Center, list the wall, roof and finish work on separate lines and show you where the new cap will sit. Nothing gets cut until you have approved that plan in writing.

Gas fireplaces in bedrooms and bathrooms

Florida's fuel gas code keeps appliances out of sleeping rooms and bathrooms in section 303.3, with a short list of exceptions. The first is a direct-vent appliance installed according to its listing and the maker's instructions.

One direct-vent manual confirms that its unit is approved for bedroom installation. A natural-vent fireplace draws room air, and the code allows vented fireplaces in those rooms only under a separate exception tied to the room's volume, so our pros confirm the vent type and the room size before anything else.