Despite the snow Sunday night, firefighters quickly responded to a room ablaze at the Montauk Yacht Club, extinguishing the flames before they spread. The fire caused minimal damage to one hotel room, thanks in part to an automatic fire alarm that summoned firefighters to the hotel, which is closed for the season.Montauk Fire Chief Joe Lenahan said Monday that Vinne Franzone, the first assistant chief, Dave Grimes, a department captain, and Domingo Schiappacasse, a lieutenant, were on duty when the department was called to an automatic fire alarm at 32 Star Island Drive at about 9:20 p.m. The alarm indicated a problem in a room in the north building along a dock across from the pool.“Chief Franzone called dispatch to confirm that we had a fire immediately,” said Chief Lenahan, who arrived about three minutes later. Within a half-hour, firefighters had put out the blaze. “Good thing the alarm system did its job,” he said.The fire damaged a bathroom and burned through an outside wall. Tom Baker, an East Hampton Town fire marshal who is investigating, estimated that the damages total about $10,000.The cause may have been a problem with a built-in electric wall heater, which dates to 1975. “I’m on the fence,” he said Wednesday. “It’s either the wires leading to the heater or the heater itself.”The investigation is continuing, but Mr. Baker said the fire does not appear to be suspicious. He has recommended to the club’s managers that similar heaters in other rooms be replaced because of their age.“It was a good stop by the Montauk Fire Department,” Mr. Baker said. “They did a really good job under the circumstances, getting things done,” he said, referring to the snow and ice.Five pieces of apparatus from the department responded, along with an engine from the Amagansett Fire Department and the rapid intervention team from the East Hampton Fire Department. The Springs Fire Department was asked to stand by at Montauk’s headquarters.One firefighter injured his shoulder and was treated at the hospital on Monday morning, Chief Lenahan said.