MOBILE, Ala. (AP) _ A malfunctioning heating system may have been responsible for carbon monoxide poisoning that killed an elderly woman and critically injured eight other people in a private ''mini-nursing home,'' police say.

Police Maj. Tommy Lee said emergency units were called to the residence in a private neighborhood about 10 a.m. Wednesday by a police officer, Sgt. James West, who went to the house to visit his mother, 76-year-old Jimmie West.

Lee said they found the injured in various states of semi-consciousness. They were taken to three different hospitals for treatment of carbon monoxide poisoning, and four were listed in critical condition.

Lee said the central heating system appeared to be defective, but the investigation was continuing.

Dr. Gary Cumberland, a state pathologist, today identified the dead woman as 94-year-old Lena Harbin, and said she died of asphyixation due to carbon monoxide poisoning.

The residence was a ''mini-nursing home'' that was operated by 62-year-old Joseph Kozlowski and his wife, Nancy, according to Mobile Police.

Mrs. Kozlowski was in stable condition at South Alabama Medical Center where her husband was in critical condition.

Also in critical condition was Janice Miller. Kathleen Weisler, another resident and a victim of Alzheimer's disease, was in stable condition, according to hospital officials.

The police sergeant's mother was in intensive care at Providence Hospital.

The remaining victims were admitted to Mobile Infirmary. They were identified as Nettie Rogers and Eva Monk, both in critical condition, and Veta Jones, who was in fair condition late Wednesday.

Erin Wheeler, the Pensions and Security department's director in Mobile, said the six invalid people living at the residence were placed there by relatives and the home violated no regulations of her department.

However, she said state law requires a ''domiciliary license'' if the residence is occupied by two or more elderly patients, and state Health Department spokesman Jim Cooper said the Kozlowskis did not have one. He said he did not know if they had applied for a license under the program, which is only about a year old.

Gary Rehm, a spokesman for Mobile Gas Corp., said the company sent a representative to assist the coroner and the Fire Department, but he declined to comment on the cause of death.

Ken Few, a paramedic, said when emergency squads arrived at the residence, they found nine adults in the house.

''There were six invalids that were being taken care of in the mini-nursing home,'' Few said. He said the other three people were the Kozlowskis and a woman who apparently assisted the couple in caring for the patients.

Few said all of the injured and the dead woman were found in their beds, except for a woman who was unconscious out on the couch.