The owner had to get a licensed plumber and gasfitter to repair Playter's work.
The incident has prompted a warning from the Plumbers, Gasfitters and Drainlayers Board to homeowners to use only authorised and competent tradespeople.
"There are serious health and safety risks associated with sanitary plumbing carried out by an unauthorised person," said the board's deputy registrar, Kern U'ren.
"Any defective plumbing work has the potential to cause disease and serious damage to the home and in this case, the poor workmanship led to flooding."
Plumbing, gasfitting and drainlaying are regulated industries, and it is illegal for anyone to do this work unless authorised by the board.
"All authorised tradespeople are required to carry their current authorisation card," Mr U'ren said.
"We urge consumers to ask tradespeople for this card before any work commences so that they can be assured that the work is being done by an authorised and competent tradesperson."