The units have been catching alight during the recent heatwave, which has affected much of the country. 

Firefighters believe the heat is causing people to run their systems for lengthy periods of time which is then causing problems for the units. 

Albury firefighter Mark Shields said people needed to “give them a rest every so often”. 

“I think you'll find people are just leaving them on all the time and they may be overheating, or they might not be properly maintained,” he said. 

“It's causing problems with the electric motors and the control boxes. 

“Lucky, it hasn't amounted to any larges fires. 

“Smoke has gone through homes and has had to be cleared.”

Mr Shields said it was unclear why the evaporative systems, often known as “swampies”, were burning but refrigerated units were not. 

“We've had one each day over the last few days,” he said. 

The systems can cause flames to spread into a home's roof cavity which can be hard for firefighters to tackle. 

Wodonga firefighters responded to a blaze on top of a unit in Caernarvon Court on Thursday morning. 

Wodonga rostered duty officer Adrian Gutsche said people shouldn't panic, but should have the units inspected. 

Product recall lists are also available online. 

“We've had a run of them statewide and Australia-wide over the past few summers,” he said. 

“The incident (on Thursday), it was caught nice and early by the owners and the fire brigade arrived and put it out. 

“It did no further damage besides burning out the evaporative cooler. 

“The owner had had it on 24/7 for the last three or four days.

“There have been a number of product safety recalls over the past few years, we're investigating if it's one of those or not.”

Firefighter Sean Crossthwaite said he was aware of electrical circuit boards and motors causing issues. 

“It's being investigated by fire investigators so we can track down what the actual problems are,” Mr Crossthwaite said. 

“We can't single out any particular brand at this stage.”