Simmonds said she hoped to get a new compressor and the shop to be back up and running this afternoon.
A Fire and Emergency NZ spokesman said fire crews were sent to the scene of a compressor on fire at a business on Eruera St.
He said it was a small fire and crews quickly extinguished it.
A fire investigator was at the scene, he said.
A Rotorua Daily Post reporter said one fire truck and one ambulance were at the scene, however the ambulance had now left, and a firefighter appeared to be looking around the workshop with a torch
Workers seem to still be inside the workshop, she said.
A faint smoky smell is in the air and Fire and Emergency NZ staff seem to be investigating one corner of the workshop.
An electrician were also on scene.