Two of them, Christopher Bishop, 36, and Joseph Avey, 34, were on duty when they were arrested by Maricopa County sheriff's deputies early Tuesday. Darryl Lanning, 43, who used to work at the same station but resigned in January, was arrested at his home, the Arizona Republic reported.
Lanning told investigators the three were paid hundreds of dollars to torch the home for revenge.
Court documents filed by the sheriff's department say a Peoria, Ariz., firefighter, Robert Brewster, 33, hired the Phoenix firefighters to torch the home after he claimed he wasn't paid thousands of dollars for construction work he had done.
Maricopa County Sheriff Joe Arpaio said Brewster has been questioned by investigators but was not immediately charged.
More arrests are expected, the report said.