A321
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Troubleshooting
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Air Traffic Control Provided Assistance; Aircraft Equipment Problem Dissipated; Flight Crew Returned To Gate; Flight Crew Requested ATC Assistance / Clarification; General Flight Cancelled / Delayed; General Maintenance Action
Aircraft
No corrective action needed. In the interest of safety we wanted to find the source of the smell and allay the concerns of the passengers and Flight Attendants.After engines started; before we started to taxi. FA called up and reported a burning smell from the aft part of the aircraft. Captain made the quick decision to call fire trucks and return to the gate for inspections. Fire department looked and found nothing. Hazmat team also came in with tools to check for hot spots and burning smells. All of their equipment came up empty. We received the all clear from the Fire department. With maintenance we did engine runups but could not recreate the smell. Maintenance signed off the logbook. We boarded the passengers again and flew to ZZZ1. The flight was uneventful.
A321 flight crew reported a fumes event during engine start-up and initial taxi-out.  The flight returned to the gate for inspection after a Flight Attendant also reported a burning smell in the cabin.