A coronial inquest has found the death of a Queensland handyman discovered floating in a flooded basement was likely caused by a non-fatal electric shock that triggered an abnormal heart rhythm.

Stephen Leonard Viner, 57, was performing maintenance work on bilge pumps at a commercial premises in Brisbane for his cousin-in-law, Constantinos Kouzoukas, when he died on February 6, 2017.

Photos taken during the investigation into the death of Stephen Leonard Viner, 57.

The badly missed husband, father and friend was remembered by his family as being "larger than life".

Deputy State Coroner John Lock heard Mr Viner was "generous with a giving nature, down to earth, loyal and funny, respectful of all people".