A fire at The Gas Company's Campbell Industrial Park plant Saturday night took out a key unit that is required to make synthetic natural gas and forced the company to deliver a mixture of air and propane to its customers while repairs were made.

Yesterday, the plant was at 70 percent capacity, said Steve Golden, director of external affairs and planning for The Gas Company. By today, the plant should be operating at full capacity, Golden said.

When The Gas Company pumps out the propane and oxygen mixture, sometimes the pilot lights on older household appliances that run on natural gas get snuffed out. When that happens, gas can build up in a closed home or business and could become flammable, officials say.

Pilot lights in household appliances have automatic gas shut off valves, Golden said. However, most newer appliances have electronic ignitions and don't rely on pilot lights.

The company has issued an advisory to all customers receiving natural gas: If you smell gas, call The Gas Company at 526-0066 before relighting the pilot light in the appliance.

The plant fire, which was put out before the Honolulu Fire Department arrived, affected about 30,000 customers on O'ahu who may have had to relight pilot lights or have their gas lines cleared, company officials said yesterday. Some customers may not have experienced any problems at all, Golden said. The line served customers in the area from Middle Street to Hawai'i Kai.

"We wanted to make customers aware of the problems," Golden said. "We used our backup system, and when we switched from one tank to another, there was a period of time when only air went through. When too much air is in the gas line, the pilot lights go out."

About 300 calls have been logged in since the 10 p.m. Saturday fire, he said. The company uses the propane/oxygen mixture during regular maintenance, Golden said.

Reach Suzanne Roig at sroig@honoluluadvertiser.com.