Conrad J. Heimbach, a retired real estate broker, died Tuesday of heart failure at his home on Gibbons Avenue. He was 86.

A mass of Christian burial for Mr. Heimbach was being offered today at St. Dominic's Roman Catholic Church, Harford Road and Gibbons Avenue.

He retired nearly 20 years ago from C.J. Heimbach Realty and sold the business, which he had operated since 1945.

Earlier, he worked for the old Glenn L. Martin Co. and at the Washington Navy Yard.

From 1978 until the mid-1980s, he was a member of the Baltimore City Commission on Aging.

He is survived by his wife of 65 years, the former Marie Frisch; a daughter, Berta M. Parker of Dayton in Howard County; a son, Joseph C. Heimbach of Towson; seven grandchildren; and two great-grandchildren.