Marlborough volunteer firefighters responded to three more false alarm callouts at Base Woodbourne in the past five days.
Blenheim chief fire officer Rob Dalton said staff at Base Woodbourne were trying to identify the problem.
"Like most things, it will take time to fix the system," Mr Dalton said.
Blenheim and Renwick brigades responded to callouts at 11.12pm on Saturday, one on Monday about 10pm and one at 12.43am on Tuesday.
The brigade's volunteer firefighters have responded to more than 40 unnecessary callouts since July because of a faulty alarm system.
The New Zealand Defence Force did not respond to questions from the Express.
- The Marlborough Express