John Gittins, senior coroner for north Wales east and central, said the death required further investigation and adjourned the inquest.
In a tribute on a fundraising page launched to support his family, Harrison was described as a "cheeky chappy, full of character with a personality that could light up a room", and as having been "loved more deeply than words could ever express".
The GoFundMe page was set up by Kate Jones to help cover Harrison's funeral and memorial costs, as well as household bills and essential expenses while his parents take time away from work to grieve. "There are no words that can truly describe the heartbreak and devastation his parents, sisters and our whole family are experiencing," Jones wrote on the page.