A special Town Meeting on whether to approve spending $100,000 to $115,000 to replace one of the two boilers at Halifax Elementary School will most likely take place in September. “Everybody’s on board with this. It has to get done,” said Town Administrator Charlie Seelig. Seelig said selectmen will probably set the date at their meeting on Tuesday. He said a single boiler can heat the building, which houses about 650 students, on moderately cold days, but cannot handle an extended cold snap. “If one goes down, you’ve got problems,” he said. Both boilers are decades old, he said, and the town hopes to recoup some of the cost through rebates for increasing energy efficiency.