Charles B. Hoeven, 85, a Republican member of the House of Representatives for 22 years and a former chairman of the House GOP Conference and ranking minority member of the House Agriculture Committee, died of congestive heart failure Sunday in a nursing home in Orange City, Iowa.

Mr. Hoeven was elected to the House in 1942 and served in it from 1943 until 1965. He was elected first from the 8th District in the north-west part of Iowa. When this became the 6th District in 1961, he represented that until his retirement.

He was chairman of the House Republican Conference from 1957 to 1963, when he was defeated for relection to that post by Gerald R. Ford of Michigan. Ford was part of a group of young Republicans who were challenging the older leadership of their party in the House in an effort to change the GOP image.

Mr. Hoeven also was a member of the House Republican Policy Committee from 1957 to 1962, ranking GOP member of the Agriculture Committee from 1958 to 1965 and deputy minority whip from 1957 to 1965.

A native of Hospers, Iowa, and a resident of Alton, Iowa, Mr. Hoeven was a graduate of the University of Iowa.

In his home state, Mr. Hoeven was Sioux County attorney from 1925 to 1937, president of the Iowa County Attorney's Association, and president pro tem of the Iowa Senate, in which he served from 1937 to 1941.

Survivors include his wife, Velma, of Orange City, a son, Charles P., of Slater, Iowa; a daughter, Mrs. Stanley J. Marshall of Ackley, Iowa, and five grandchildren.