Date: 201910
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: A321
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Powerplant Fire/Overheat Warning
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Diverted; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: After rotation and gear retraction; on a Take Off Go Around; IMP Performance takeoff; the aircraft gave a #1 Engine Fire indication with no loss of thrust. The Captain was flying and we began to execute the emergency procedures for an engine fire in flight while calling up the ZZZ RWY 01 engine failure routing. Noting there was no loss of thrust and the engine temperature was not excessively high; we requested a heading from ATC and a climb to 5;000 feet. We followed the ECAM procedure and after reducing thrust to idle in the first step; the ECAM cleared. There was also a write up from the previous flight for one of the Engine Fire loops so we quickly discussed if that may have factored into the issue. Upon reaching a safe altitude; airspeed; and configuration; the Captain increased power in the Number 1 thrust level and we noticed no issues with the engine. It was. A few moments later; with both thrust levers in the climb detent; we attempted to climb and when the engines returned to full power; we noticed the Number 1 EGT slowly creeping up towards 790 degrees; about 40-50 degrees higher than the Number 2 engine. The engine Fire ECAM returned again and the Captain pulled back the Number 1 thrust lever which rectified the situation again. We decided to divert to ZZZ1. We ran all appropriate checklists; including the overweight landing checklist and a landing assessment. The Captain made an uneventful landing on Runway XXR and; after an inspection by the fire department; taxied to the gate.


Second narrative: Engine Fire Number 1 Warning received soon after gear retraction on takeoff. Engine continued producing thrust as threat was assessed and initial climb completed. Non-normal procedures implemented and evaluation of situation continued during initial climbout. No navigation errors on northbound Boock SID detected by pilots or noted by ATC during event. [Requested Priority Handling] and divert to ZZZ1 requested. Emergency landing procedures reviewed and preparations made for landing over maximum gross landing weight. Night visual approach Runway XXR executed without incident.Fire warning may have been triggered because one fire-detection loop on engine 1 was MELed inoperative. EGT on Number 1 was detected significantly higher than Number 2; but all other engine parameters seemed normal. It could not be determined during course of evaluation whether or not an actual engine fire had or would occur; so decision was made to divert for precautionary landing ZZZ1.


Synopsis: A321 flight crew reported Engine 1 Fire Warning on climbout.