Gas Fireplace Repair in Pasadena: Written Report in Plain Language

The call came from a homeowner on a quiet block near the Arroyo Seco corridor, just west of San Marino. She had a gas fireplace insert fitted into the original Craftsman brick hearth, installed sometime in the early 2000s to replace a wood-burning setup. One evening in December she clicked the wall switch and got nothing. No ignition, no flame, not even the faint blue glow of a pilot. Her concern was carbon monoxide. The unit sat inside an old masonry firebox with a flue liner that had already been questioned during a home inspection years earlier, and she wanted to know whether something dangerous was happening behind the decorative logs.

This is a typical scenario in Old Pasadena and the surrounding Craftsman bungalow neighborhoods. The fireplaces in these homes were built for wood fires in the 1910s and 1920s, then retrofitted decades later with gas inserts or log sets. The original firebox dimensions, the clearances to combustible trim, the condition of the flue tiles - none of it was designed for a sealed gas appliance. When something goes wrong with the pilot assembly or gas valve, the age of the surrounding masonry adds a layer of complexity you won't find in a tract home built in 1995. She needed someone who understood both the gas appliance and the Craftsman-era construction around it.

Our technician started with a millivolt reading on the thermopile. A healthy thermopile produces around 300 to 750 millivolts under load. Hers read 112 - well below the threshold needed to hold the gas valve open. That explained the dead pilot. We replaced the thermopile and tested the thermocouple at the same time, since both components sit in the pilot flame path and tend to degrade together in units that cycle on and off through mild Pasadena winters without sustained use. The gas valve itself checked out. With the new thermopile installed, the pilot held and the burner fired on command. We confirmed proper flame pattern across all logs and verified CO readings at the vent termination per NFPA 211 inspection standards.

The direct-vent configuration on her insert was still intact and drawing correctly, which was good news. In Craftsman bungalows along the Arroyo Seco corridor and into San Marino, we sometimes find that retrofit venting was routed through old clay flue liners without a proper sealed chase, which turns a direct-vent appliance into something closer to a ventless unit pulling combustion air from the room. That was not the case here. We documented everything, tagged the unit with the service date, and recommended annual gas fireplace maintenance before each heating season. If your gas fireplace won't light, or if you smell gas near an older insert, don't keep clicking the igniter. Call us for a diagnosis.