Robert H. Hart Jr., 69, who died of carbon monoxide posioning in a Washington town house, was a retired government electrician and part-time taxi driver.

The bodies of Mr. Hart and a family firend, Kate V. Coleman, were discovered after relatives of Mrs. Coleman became concerned when she did not report to work. Mrs. Coleman operated the building, which she had inherited a few weeks ago, as a boarding house.

Gas company officals said that the home's furance exhaust flue was blocked by deteriorated brick and mortar, forcing the fumes back down the flue into the building.

Mr. Hart was a native of Rocky Mount n.c., and had lived in Washington since 1931. He worked as an electrician for the General Services Administration for 29 years before retiring in 1970. He also had been a part-time taxi driver with Yellow Cab in Washington for the past 20 years.

He had belonged to Meridian Hill Baptist Church since 1960 and had served on the church's board of trustees for the past three years.

Survivors include his wife, Ann E., and two sons, Ricky and Gerald, all of the home in Washington; two other sons, Donald, of Washington, and Robert Terry Hart, of Los Angeles, and four grandchildren.