Gas Log Sets Matched to Your Firebox

Most Phoenix-area houses built since 1999 already have a gas log set, because state law, A.R.S. 9-500.16, had Valley cities limit new fireplaces to gas or electric log units or EPA-certified appliances from the end of 1998. In Buckeye, Queen Creek and San Tan Valley, about nine in ten homes were built in 2000 or later. Their logs are part of a listed appliance, and replacement logs need to be the ones that appliance was tested with, not whatever set fits the opening.

Older open masonry fireplaces are the other half of the work. In a 1970s Sun City or Tempe living room, a log set is a way to keep the fireplace without the wood, and the choice of burner size, log style and vented setup is wider there. Either way, logs that crack, crumble or sit in the wrong spot are the usual reason a fire looks dull or leaves black streaks.

Signs you need this

• Logs are cracked, crumbling or missing pieces
• Black soot builds on the logs or the firebox walls
• Flames look thin, patchy or rise from only part of the burner
• The ember bed has burned down to bare sand or grate
• You want an open brick fireplace to burn gas instead of wood

How we do it

1. Measure the fireboxWidth at the front and back, depth and height, plus the gas supply size at the fireplace.
2. Match the setFor a factory-built unit, the logs listed for that model; for masonry, a burner and set sized to the opening.
3. Place by the diagramEach log goes on its pins or marks, and embers go where the manual shows, not where they look nice.
4. Burn and adjustWe run the set long enough for the flame to settle, then check for flame striking logs and for proper venting.

Why logs turn black, and how placement fixes it

Soot on gas logs almost always means flame is hitting a cooler surface it was never meant to touch. A log knocked off its pin during a dusting, ember material piled over the burner ports, or a replacement log of the wrong shape will all do it. The flame cools, burns incompletely, and leaves carbon behind, often with an odd smell the first few minutes.

The fix is usually modest: reset the logs to the diagram, clear the ports, replace damaged pieces. Logs that blacken again after a correct layout point to a burner or air-mix problem, and we look at that next.

Replacement logs for factory-built fireplaces

The rating label, usually on a chain or plate behind the lower grille, gives your fireplace's brand and model. That model was tested with one log set and one burner, and its manual names them. We work from that label, so the logs you get are the ones the unit was approved to run with.

Phoenix's code treats fireplaces built on or after December 31, 1998 as gas or certified units that may not be altered to burn wood, and alterations need a city permit. Swapping in the listed replacement logs keeps the unit as it was approved. If anything beyond that is planned, we check what your city requires first.

Adding logs to an open masonry fireplace

A brick fireplace from the 1960s or 1970s can take a vented log set with the damper fixed open, so exhaust leaves through the flue the way smoke did. We check the flue and damper first and size the burner to the firebox. If the gas stops short of the fireplace, HomeGuide puts extending an existing line at $350 to $2,000.

Once on gas, that fireplace can run on No Burn Days, because Maricopa County exempts gaseous fuels, gas logs included, from the wood ban.

The county's Fireplace Retrofit Program

Maricopa County runs a Fireplace Retrofit Program for homes inside a set boundary in central and west Phoenix, roughly between the 67th Avenue alignment, Dunlap Avenue, 16th Street, Camelback Road, 24th Street, Carver Road and the north edge of South Mountain Park. The county says it will pay up to $2,000 per gas log set retrofit, with a $2,500 voucher for the first 17 eligible participants, one per household. The home needs Southwest Gas service, and the fireplace needs a chimney cap and a working damper.

The county uses its own installer for the log set; we are not part of the program. Where we come in is the step before: the program asks the homeowner to get an inspection and a cleaning, with a receipt stating the fireplace is safe for retrofit. The inspection is free, the cleaning is priced at it, and a missing cap or stuck damper can be put right first so the house qualifies. Funding status isn't stated on the county page, so check current availability with the county.