Theodore C. Burkhardt, retired founder and owner of a small Baltimore fuel oil company that was known for its customer service, died of heart failure Friday at Johns Hopkins Bayview Medical Center. The longtime Highlandtown resident was 81.

A Baltimore native who was raised on South Highland Avenue in Canton, Mr. Burkhardt attended city public schools until leaving to help support his family -- but returned to his education later in life and earned a bachelor's degree when he was in his 70s.

He founded the independent T.C. Burkhardt Oil Co. near his childhood home in 1946, with a single Ford fuel delivery truck, after serving in the merchant marine and Coast Guard during World War II.

The company moved to Eastbourne Avenue in Canton and grew to four employees and six trucks as it earned a reputation for swift, personalized customer service.

"He even interrupted his 79th birthday party to take a service call because the home had no heat and he knew the family had children," said son Charles T. Burkhardt of Dundalk.

"His firm survived on a tradition of service and, whenever possible, discount prices," said James A. Genthner of Northwood, a customer of many years. "Ted was a gentleman of the old school who was always gracious and friendly. He often answered the telephone himself to take orders for fuel oil or burner service."

Mr. Genthner recalled a Christmas Eve problem, when the 1941-vintage furnace in his mother's then-vacant old home failed and the pipes could have frozen in the cold. "When I called Ted, there were no excuses that tomorrow was Christmas Day and they couldn't come until the day after," he said.

David L. McCord, who worked in the oil company's service department for 16 years, recalled Mr. Burkhardt's dedication: "He'd work from 6:30 a.m. to whenever. He was the hardest-working person I ever knew. I'm half his age and had to give it everything I had just to keep up with him."

He added, "The customers always liked him because they knew he'd do anything to satisfy them and get the heat back on. He loved going out on service calls, and even drove the oil truck until he was 78."

The son said Mr. Burkhardt had "a strong German work ethic," from the time he started in business as a one-man operation. He also noted his father's belief in the importance of education: "He went to night school to earn his GED in the late 1970s. He later earned an associate's degree in 1987 from Dundalk Community College, and his bachelor's degree in business from Morgan State University in 1996."

Mr. Burkhardt retired last year after selling his business to Carroll Independent Fuel Oil Co.

He enjoyed making plumbing and carpentry repairs to his Highlandtown home, and was a former president of the Canton Pleasure Club.

His marriage to the former Elizabeth Radomski ended in divorce.

Mr. Burkhardt was a communicant of Sacred Heart of Jesus Roman Catholic Church, Foster Avenue and Conkling Street, where a Mass of Christian burial was to be offered at 10 a.m. today.

In addition to his son, Mr. Burkhardt is survived by two granddaughters and three great-grandchildren.