Why won't my gas fireplace light when it's very cold outside?

Propane hates the deep cold

Liquid propane has to boil into vapor to feed your fireplace, and it does that slowly when it's frigid — especially with a tank that's low or on the small side. On a single-digit morning in Fairview, Candler, or up at a Cashiers cabin, a nearly empty tank simply can't produce vapor fast enough, and the fireplace won't light or won't hold flame.

Keeping the tank level up through winter is the simplest guard against this. If the tank is undersized for the load, that's worth a look with your supplier.

Sensors fail at the margins

A thermocouple or thermopile that's aging still works in mild weather, but cold is the tipping point. In deep cold the gas valve and sensors are working against a harder environment, and a marginal sensor finally drops below the millivolts required to prove the pilot or open the main valve. It looks like a cold-weather problem; it's really a worn part the cold uncovered. We stock these and usually fix it in one visit.

Cold flue, cold house

A flue that's been sitting cold fills with dense, heavy air — cold air sits in the chimney like a plug — and WNC's ridges, valleys, and tall trees make downdrafts worse. That column of cold air can push down hard enough to nudge a small pilot flame off its sensor. Our techs sort out which of these it is quickly, and it's licensed gas work either way, so leave it to us. Call (828) 545-0525.