Montgomery County School Superintendent Edward Andrews officially announced his resignation yesterday, and within hours candidates seeking election to the school board began to exploit it for political gain.

Although board members and candidates universally praised Andrews and expressed sorrow at his resignation, the candidates for four open board seats offered contradictory warnings about its implications.

The two conservative incumbents running for reelection, Joseph Barse and Carol Wallace, said their liberal challengers were likely to search for a new superintendent in the mold of Andrews' predecessor, Charles M. Bernardo, an innovative and controversial leader who advocated busing for racial integration. Bernardo was ousted by the conservative majority that took over the board in 1978.

Barse and Wallace said several leaders of EDPAC, a political action committee endorsing four liberal candidates, were former board members who originally hired Bernardo and supported his philosophies.

"It's quite possible that the EDPAC people will try to bring back Bernardo," said Barse. "Everything they have said indicates that they supported his policies." He added that Bernardo appeared to be interested in reclaiming a job in the county school system, but he offered no specific evidence.

Barse said former board member and county NAACP Chairman Roscoe R. Nix, former board member Harriet Bernstein, and current board member Blair Ewing, all of whom belong to EDPAC, were "major supporters of Bernardo."

Ewing, the lone liberal on the seven-member board, said Barse was wrong to suggest that EDPAC candidates, if elected, would hire Bernardo.

"Categorically, Charlie Bernardo is certainly not going to apply for this job and if he did he would certainly not get it," Ewing said. He said it is "flatly untrue" that Bernardo, who works in Florida, wanted to return to Montgomery County.

Ewing implicitly blamed the current board majority for Andrews' departure, scheduled for next June, a year before his term expires. "It is more essential than ever before to elect a new board," Ewing said. "This board has been unable to hold on to superintendents."

EDPAC candidate James Cronin said the board's handling of the county-wide school closings was responsible, in part, for Andrews' resignation as chief of the 92,000-pupil school system. "A contributing factor has to have been the tension he has been under this past year and a half," Cronin said.

Andrews, at an afternoon press conference, said that although he disagreed with the board majority on some issues, his main motive in resigning was to escape the fatigue of working 70 to 80 hours per week during the past 18 months.

"There have been differences" with the board, Andrews conceded. "I continue to believe that what I have recommended to the board was best . . . but I agree with most of the educational decisions that have been made by this board."

Andrews vowed to stay out of the school board race, saying "it would be prostitution of my role to affect the outcome." He said his opinions of the race "remained private and have not been reported accurately in the press." Several associates of Andrews have said that he hoped to see the current board majority replaced. Marian Greenblatt, leader of the board majority, said the news accounts were "utter fabrications."

Andrews said he planned to announce his retirement much sooner, but waited until this week to oversee the outcome of school closing appeals. He said he was delayed as well by the resignation last July of board member Elizabeth W. Spencer, who is the Republican candidate for the 8th Congressional District seat.