Consumer and Business Services has issued a public warning about Adelaide-based solar panel company, Unleash Solar.
Commissioner for Consumer Affairs Paul White said the company was being investigated for 17 complaints about faulty equipment and warranty work not being completed.
Mr White said Unleash Solar was not dealing satisfactorily with customers' issues.
"What the company has told us is that it will take between three and six months to source replacement inverters from China," he said.
"We believe that's not reasonable and those goods are unfit for purpose and it needs to be rectified sooner than that.
"We're advising the public to be wary of dealing with this company, Unleash Solar." The ABC tried to contact the company for a comment.
Unleashed Solar is a sponsor of A-League team Adelaide United and SANFL club Woodville West Torrens.