The abattoir's incinerator would be undergoing "interventions" by its manufacturer on Thursday, WasteServ said.
The intervention would include the periodic setting and calibration of one of the burners, WasteServ chief executive Vince Magri said.
Labour environment spokesman Leo Brincat asked whether carcasses were being stored while the incinerator was off and whether it was damaged.
WasteServ replied saying it was normal practice to do tests on the incinerator to ensure it was working properly, adding it was stopped every six weeks for maintenance.
It said that between January and November the incinerator underwent nine interventions to adjust some parts and fix some damage. During these periods, the waste was put in cold stores and afterwards incinerated.
The incinerator operated through December and underwent routine maintenance last month.