"Because we've had so much wrong with it, we are considering our options," said Mr Hathaway.
He said the heat pump was running fine at the moment but council was awaiting an engineer's report to confirm this.
McAlpine Hussman had originally been contracted to fix the faults and were contacted to confirm whether it was viable to keep all or part of the pump.
But council contacted Cooke Industries (the original suppliers of the equipment) as the contractors had taken too long to undertake the investigation.
They recommended an engineer and council expected to hear from them next week.
Aurecon Consulting estimated a full replacement would cost about $400,000.