John F. Herrity, the feisty chairman of the Fairfax County Board of Supervisors, may have escaped the iron boot of the District of Columbia government but not its financial bite.

City officials said yesterday that they have confirmed that four back parking tickets levied on Herrity's car have not in fact been paid. Herrity challenged the tickets when he discovered his green Toyota had been immobilized by a D.C. Transportation Department "boot" on a downtown street Tuesday.

Herrit, who made a quick call to the District Building Tuesday to get the boot removed without first paying the tickets, owes the city $115 for the tickets, late penalties and boot fee, officials said.

"I'll send him a very curt letter saying 'pay up,'" Transportation Department parking enforcement chief John M. Brophy said yesterday.

Brophy had been more conciliatory Tuesday when Herrity complained about the boot from a phone booth near his manacled car in the 1700 block of M Street NW.

Herrity had first attempted to call the regular Transportation Department number on the booting notice, but got a busy signal. He then called the office of City Administrator Elijah B. Rogers, where an assistant called Brophy and told him to call Herrity.

Herrity told Brophy he did not believe he had accumulated the four unpaid tickets and there must be a mistake. Brophy told him that the computer used for matching car license numbers with outstanding parking tickets had made similar errors in the past, and Herrity might be right.

Brophy then ordered the boot removed from Herrity's car and said he would verify the validity of the four parking tickets later.

Ordinarily, the procedure is just the opposite: A motorist with a booted car cannot get it liberated until he has paid all back tickets, or has contested them before a hearing examiner. Paying the tickets and arranging removal of the boot often takes 24 hours or more. Herrity's Toyota was set free in less than an hour.

Brophy denied that the city administrator's office pressured him to help Herrity.

"He's not the first person who's gotten this kind of treatment," Brophy said. Because of computer problems, he said, other motorists making "reasonable" assertions that they have no outstanding tickets have also had their cars unbooted.

But a check of Transportation Department records yesterday confirmed that the computer was right about Herrity's tickets, Brophy said. The Toyota had accumulated four tickets, two as recently as December, and one as far back as November 1976, Brophy said.

Herrity said yesterday he did not want to comment until "I get the letter from Mr. Brophy and have a chance to check out my own records, my check stubs and things like that on each one of these tickets."

In an earlier interview, Herrity said he said he did not believe he had received any of the four tickets, "but I have four teen-age drivers in my family," and one of them may have been responsible.