Seventy-eight families whose condominiums is a District Heights development have been without heat since Dec. 4 learned yesterday they will either have to pay $400 to $500 apiece for new gas pipes or pay less to have the pipes repaired, knowing they could again leak.

Jerry Raines, president of the plumbing company that has been working on the pipes since the gas was shut off by the Washington Gas Light Co. on Dec. 4, said repairing the leaky and corroded pipes might only be a temporary solution.

"If they go out there and dig up all the pipes and decide they can repair them, they might run into the same leakage problem in the near future," Raines said. 'If they go for new pipes, $30,000 to $40,000 is a ballpark figure" for the total cost of replacement.

The families-totaling 390 individuals-have either been living with friends or in hotel or in their unheated homes in the Old Towne Village development despite the fact their condominium units have been declated unfit for human habitation.

Yesterday workmen were attempting to complete the excavation of the nearly 2,000 feet of galvanite pipe in order to determine if the leaks were so numerous that new pipes will have to be put in.

Wednesday, Carl Ruff, property manager for the project had expressed the hope that the pipes could be reapired so the residents can have their heat backed by next week. If new pipes have to be installed the jon will take three weeks, according to the plumbers.

Yesterday Ruff said that he thought replacing the pipes immediately was the most logical thing to do. "They may save some money now on repairs but it isn't going to get any warmer and if this happens again it would be outrageous," he said. "Our recommendation would be to replace the pipes. They might end up having to do that anyway after digging up all the old pipes. Then it will cost even more.

Although Ruff would not speculate on the cost of repairing the pipes, residents said yesterday that they had been told the minimum cost per family at this point would be about $150.