Gas Fireplace Cleaning in Woodland Hills: Written Report, Licensed Technicians

A couple on a quiet street off Tujunga Village called us last November after their gas log set started producing a faint sulfur smell within minutes of lighting. They'd converted their wood-burning masonry fireplace to gas logs about four years earlier, hired someone off a neighborhood app, and hadn't thought much about it since. The original firebox was built in the late 1950s with unlined brick, and the gas log burner had been dropped in without a proper masonry-to-gas conversion assessment. No liner was installed. The damper clamp was missing, so the damper kept closing on itself. They assumed gas fireplaces didn't need maintenance. That smell told them otherwise.

We hear versions of this story regularly from homeowners in the Ventura Boulevard flats and along the Moorpark Street corridor, where postwar ranch homes and mid-century builds were designed for wood fires. When a gas log set gets installed into one of these original masonry fireboxes without addressing the flue condition, you end up with problems that don't show up right away. Soot collects on ceramic logs in odd patterns. The pilot assembly corrodes faster than it should because the old clay tile liner, if there is one, doesn't handle combustion byproducts from gas the same way it handled wood smoke. The homeowner doesn't realize anything is wrong until they smell it or until a CO detector goes off.

For the Tujunga Village job, we ran a Level 2 inspection per NFPA 211, which includes a camera scan of the full flue interior. The scan showed cracked mortar joints at two points in the upper third of the chimney and a deteriorated clay tile liner section that was allowing combustion gases to seep into the surrounding brick. We cleaned the pilot assembly, tested the thermocouple for millivolt output, and inspected every ceramic log for heat fractures. The thermocouple was weak, reading below 20 millivolts, which explained why the pilot had been dropping out intermittently. We replaced it on the spot. A proper damper clamp was installed so the flue stays open whenever gas is present.

We also verified the CO detector placement in the room and tested it. One thing that surprises people along the Moorpark Street corridor and across the Ventura Boulevard flats: vented gas log sets in converted masonry fireboxes need the flue fully open at all times during use, but ventless units have entirely different oxygen depletion sensor requirements. Mixing up those two maintenance approaches is common and dangerous. Every gas fireplace cleaning we perform includes documenting whether your setup is vented or ventless and confirming the firebox meets current CSIA guidelines for that configuration. If your gas logs were installed into an older Studio City masonry chimney without a fireplace inspection first, that's the place to start.