A Hyattsville dentist has been ordered to pay approximately $48,500 to 22 former tenants for overcharging them rent at an apartment building he owned on Capitol Hill.

"This will be a real boon to most of the tenants, especially the ones on low income, because it means they certainly stay around here for a longer period of time than otherwise would have been possible," said David Schlein, president of the building' Union.

The Jan. 5 order by the District's Rental Accommodations Office resulted from a 1976 complaint by the tenants of the 16-unit building at 529 G St. SE. The order stated that their landlord, Bernard Totz, was violating the city's rent control laws. Totz since has sold the building to J.C. Associates, which as not involved in the case.

Totz called the decision "a total injustice" and said he planned to appeal. He refused to comment further.

The decision covers excessive rents charged between September 1974 and Setember 1977 and orders the refunds to be three times the actual overcharge and to include interest. Payments to Totz's former tenants, nine of whom still live in the building, are to range from $134.31 to $4,215.50.

Overcharges at the building continued through October 1980, but tenants must file a new complaint if they wish to try to recover that money, the agency's order said.

Schlein, s tenant since 1978, said he and other current and former tenants were planning to take that action against Totz and to discuss refunds with J.C. Associates, which bought the building in April 1979. He said that in the fall of 1980 the tenants and J.C. Associates agreed on the higher rent to be effect from then on.

Totz declined to discuss the alleged additional overcharges, and a spokeswoman for J.C. Associates said she was unaware of such complaints.

The tenants' 1976 complaint against Totz was triggered when he raised rents after replacing a central heating system with individually metered gas heaters in each apartment, Schlein said. He said tenants expected a rent decrease to reflect the fuel cost no longer paid by Totz and the rent increase angered them.

The Rental Accommodations Office agreed with the tenants, but no rent refunds were made because of several appeals by Totz and bureaucratic delays, Schlein said. Totz lost appeals before the agency's commission and the DC. Court of Appeals.

Angeline L. Buckner, who has lived for 13 years with her two sons in her two-bedroom apartment, said she is happy that the tenants' case against Totz may be over, but "I'm not counting my chickens before they hatch."

She said she is looking forward to receiving the $4,114.77 ordered paid to her because she is disabled and has not been able to work steadily. The District's agency found Buckner was charged $18 to $73 a month more han the $147 rent legally allowed. The three-year overcharge totaled $1,348.

Buckner, secretary-treasurer of the Tenants Union, said she hasn't decided how to spend the money, but she and other tenants have considered putting their payments toward buying the apartment building and turning it into a cooperative.