Firefighters called to 'incident' at RAF Wethersfield
They said said a build-up of pressure in a fire suppression system had created a small hole in a roof.
Firefighters attended a former air base which is being used to house asylum seekers following a reported incident in a disused building.
Essex Fire and Rescue Service, which were called to the site in Wethersfield at 1.18pm on Thursday, said a build-up of pressure in a fire suppression system had created a small hole in a roof.
Nobody was injured or had to be evacuated and the scene was made safe, the fire service said.
In a statement, a fire service spokesperson said: "On arrival crews found that the pressure in a fire suppression system had built up and created a small hole in the roof of a disused building on the edge of the site.
"Crews worked with the site to make the scene safe.
"No one was injured or had to be evacuated."
The site at Wethersfield has been earmarked to house 1,700 asylum seekers by the autumn as part of Government plans to reduce the money spent on hotels.
The first asylum seekers moved onto the site in July.