EVENT 915 Open/Male 11/14 Yrs 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 2 | Sebastian Rama | 12 | Co St Albans | 5:27.71 |
| 3 | 4 | Jacob Wadley | 12 | Colchester | 5:27.16 |
| 4 | 6 | Louis Santillo | 12 | Putteridge | 5:25.00 |
| 5 | 5 | Sebastian Fraser | 12 | Flitwick | 5:26.60 |
| 6 | 3 | Jack Gulliford | 12 | DunmowAtlant | 5:27.60 |
| 7 | 1 | Harry Larham | 11 | Co Peterboro | 5:27.96 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 8 | Zach Bramley | 12 | Hoddesdon | 5:24.33 |
| 2 | 10 | Tommy Camilotti-Titon | 12 | Hatfield | 5:21.70 |
| 3 | 12 | Tyler McLaughlin-Bell | 12 | Newmarket | 5:18.95 |
| 4 | 14 | Tyatt Cole | 12 | Bo Southend | 5:16.40 |
| 5 | 13 | Jack Alexander | 12 | teamipswich | 5:18.57 |
| 6 | 11 | Freddie Sargeant | 12 | teamipswich | 5:20.98 |
| 7 | 9 | Stefan Sorcinelli | 11 | Co St Albans | 5:22.14 |
| 8 | 7 | Benji Perry | 12 | Dunstable | 5:24.49 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 16 | Victor Dryankov | 12 | Thurrock | 5:11.10 |
| 2 | 18 | George Headford | 12 | Basildon Ph | 5:10.40 |
| 3 | 20 | Marco Soto-Toth | 12 | Co Peterboro | 5:09.00 |
| 4 | 22 | George Abram | 12 | Co Norwich | 5:06.70 |
| 5 | 21 | Alexander Irish | 12 | Newmarket | 5:08.80 |
| 6 | 19 | Julien Vannier | 12 | Hatfield | 5:09.57 |
| 7 | 17 | Joseph Payne | 12 | Colchester | 5:11.06 |
| 8 | 15 | Charlie Searle | 12 | Co Norwich | 5:16.00 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 24 | James Nelson | 12 | Co St Albans | 5:05.30 |
| 2 | 26 | Archie Georgakis | 13 | Basildon Ph | 5:04.46 |
| 3 | 28 | Jasper Dearden | 13 | Chelmsford | 5:04.30 |
| 4 | 30 | Max Hart | 13 | Verulam | 5:04.17 |
| 5 | 29 | Carl Manuel Bendanillo | 13 | Norwich Swan | 5:04.25 |
| 6 | 27 | Arthur Juviler-Bacon | 12 | Linslade | 5:04.40 |
| 7 | 25 | Fletcher Waugh | 12 | Colchester | 5:04.81 |
| 8 | 23 | Ethan Harragan | 13 | Basildon Ph | 5:05.60 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 32 | Jeremy Cox | 12 | Bishop Stort | 5:02.60 |
| 2 | 34 | Senan Brullo | 13 | New Hall | 5:02.00 |
| 3 | 36 | Tobias Watson | 13 | Bo Southend | 5:00.20 |
| 4 | 38 | Harrison Burridge | 13 | Co Cambridge | 4:58.17 |
| 5 | 37 | Charles Pritchard | 12 | Stevenage | 4:59.09 |
| 6 | 35 | David Hoara | 12 | Thurrock | 5:01.90 |
| 7 | 33 | Aiden Gale | 13 | Leiston | 5:02.14 |
| 8 | 31 | Hugo Redel | 13 | Verulam | 5:03.79 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 40 | George Connor | 13 | Colchester | 4:50.94 |
| 2 | 42 | Leo Sims | 13 | Hatfield | 4:48.98 |
| 3 | 44 | Guy Spearman-Baines | 14 | Bishop Stort | 4:46.24 |
| 4 | 46 | Miles Copping | 14 | Co Cambridge | 4:45.78 |
| 5 | 45 | Nathan Rojee | 14 | Co Cambridge | 4:45.95 |
| 6 | 43 | George Sims | 13 | Hatfield | 4:48.02 |
| 7 | 41 | Daniel McGrath | 13 | Norwich Swan | 4:49.31 |
| 8 | 39 | Apollo Pop | 13 | Chelmsford | 4:53.61 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 48 | Thomas Mutton | 13 | Deben | 4:43.90 |
| 2 | 50 | William Cornwell | 14 | Rochford | 4:42.60 |
| 3 | 52 | Alfie Larham | 14 | Co Peterboro | 4:40.89 |
| 4 | 54 | Hugo Harley | 14 | Watford SC | 4:39.81 |
| 5 | 53 | Jude Wankowski | 13 | teamipswich | 4:40.00 |
| 6 | 51 | Henry Chaloner | 14 | Biggleswade | 4:42.29 |
| 7 | 49 | Johnny McAuley | 13 | Co Peterboro | 4:43.67 |
| 8 | 47 | Riccardo Di Maria | 14 | Co Norwich | 4:44.22 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 56 | Noah Conroy | 14 | Bishop Stort | 4:39.31 |
| 2 | 58 | Noah Goodson | 14 | West Norfolk | 4:35.87 |
| 3 | 60 | Lewis Gardner | 12 | Basildon Ph | 4:34.76 |
| 4 | 62 | Aaron Rawnsley | 14 | Harpenden | 4:28.38 |
| 5 | 61 | Benjamin Piscopo | 13 | Co Peterboro | 4:33.50 |
| 6 | 59 | Jack Lees | 13 | Epping For't | 4:34.90 |
| 7 | 57 | Finley Burford | 14 | Basildon Ph | 4:38.00 |
| 8 | 55 | Jack Munday | 14 | teamipswich | 4:39.32 |