The Firefighters Union says its members will keep fire trucks outside stations at the end of a shift, until stations are properly equipped.
Firefighters say their health is at risk from the diesel fumes produced by idling fire trucks every time they receive a callout.
The union says up to 20% of stations nationwide still need diesel extractor fans.
National Secretary Derek Best says firefighters are waiting for the promise of installation to be honoured.
The Southland Area Manager for the New Zealand Fire Service, Brendan Nally says firefighters at the Invercargill station will recieve an extractor system within six months.
Mr Nally says parking outside increases injury risk to firefighters and can also damage the vehicles.
