B737-300 FLT CREW HAS A WHEEL WELL FIRE; DECLARES EMER AND RETURNS FOR LNDG AT ZZZ.

Narrative

DURING CLB PASSING FL200 TOWARDS FL240 AN INDICATION OF A WHEEL WELL FIRE WAS INDICATED. MY FO WAS FLYING. HE CALLED FOR THE WHEEL WELL FIRE QRC. WE WERE CLBING AT THE VNAV IAS OF 305 KTS. THE QRC CALLS FOR SPD MAX OF 270 KTS. AS FO WAS SLOWING I NOTIFIED THE FLT ATTENDANTS OF OUR SIT AND DID NOT WANT THEM ALARMED AS I KNEW IT WAS GOING TO GET LOUD AT THAT ALT AND SPD WITH 3 LNDG GEAR EXTENDED. SHORTLY AFTER THE SPD REACHED 270 KIAS AND WE FOLLOWED THE QRC. I THEN DECLARED AN EMER WITH ATC. I TOLD HIM WE WERE LEVELING AT FL220 WE HAD AN INDICATION OF A WHEEL WELL FIRE AND WANTED A TURN BACK TO ZZZ. I SAID I WOULD BE GETTING HIM THE SOULS ON BOARD AND WE HAD HRS OF FUEL REMAINING. I WAS SURPRISED THAT HE WANTED US TO CONTINUE N ON THE DEP. I RESTATED WE WERE AN EMER ACFT WITH AN INDICATION OF A WHEEL WELL FIRE AND I WANTED A TURN BACK TO ZZZ. HE COMPLIED AND WE DSNDED TO FL210. I THEN GAVE FO THE RADIOS AND HE CONTINUED TO FLY. I THEN USED THE FLT MANUAL TO COMPLETE THE WHEEL WELL FIRE CHKLIST PER THE QRC. USED ACAR'S AND PUT A CALL ME IN TO DISPATCH. I THEN CALLED THE FLT ATTENDANTS AND GAVE THEM A BRIEFING. I DECIDED TO DO A PREPARATION FOR EVAC BECAUSE THE CHKLIST SAID THE FIRE LIGHT OUT DOES NOT ENSURE THE FIRE IS OUT. THEREFORE I WAS UNSURE OF THE TIRE RUBBER REMAINING; ETC. I SPOKE WITH DISPATCH AND MAINT CTL ASKED FOR LNDG PERFORMANCE; ETC. I WENT TO THE BOOK AND CHKED THE LNDG DISTANCE AT OUR WT AS WE WERE OVERWT FOR THE LNDG. WE ASKED FOR THE LONG RWY AND THE ARR AND LNDG WAS UNEVENTFUL. I DID TAKE THE AIRPLANE FROM THE FO AFTER ALL WAS ACCOMPLISHED AND WE WERE ON DOWNWIND FOR LNDG IN THE EVENT THERE WAS STRUCTURAL ISSUE ON LNDG. HE FLEW AN EXCELLENT AIRPLANE TO THE DOWNWIND.