EVENT 426 Mens 11/14 Yrs 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 2 | 2 | Jack Despy | 11 | Basildon Ph | 5:59.34 |
| 3 | 4 | Ethan Howard | 12 | Potters Bar | 5:51.11 |
| 4 | 6 | Thomas Deaton | 13 | Newmarket | 5:46.07 |
| 5 | 5 | William Fawcett | 12 | Watford SC | 5:48.80 |
| 6 | 3 | Patch Robinson | 12 | teamipswich | 5:59.01 |
| 7 | 1 | Isaac Farrugia | 12 | Basildon Ph | 6:00.70 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 8 | Daniel Kendall | 13 | Co Ely | 5:43.42 |
| 2 | 10 | Oliver Blight | 13 | Hatfield | 5:43.12 |
| 3 | 12 | William White | 12 | Harlow Pen | 5:41.90 |
| 4 | 14 | Louis James | 13 | Thetford | 5:41.00 |
| 5 | 13 | Menuka Jayakody | 13 | Norwich Swan | 5:41.20 |
| 6 | 11 | Joel Pietersen | 12 | Hatfield | 5:43.00 |
| 7 | 9 | Ethan Angel | 13 | teamipswich | 5:43.37 |
| 8 | 7 | Daniel Lewis | 13 | Chelmsford | 5:44.99 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 16 | Jack Juggins | 13 | Team Luton | 5:37.99 |
| 2 | 18 | Ben Minister | 13 | Thurrock | 5:33.10 |
| 3 | 20 | Joshua Martin | 13 | Co Peterboro | 5:27.74 |
| 4 | 22 | Finn Cooper | 13 | teamipswich | 5:27.22 |
| 5 | 21 | Bartholomew Tozer | 14 | West Suffolk | 5:27.27 |
| 6 | 19 | Reece Simpson | 13 | Co Peterboro | 5:32.43 |
| 7 | 17 | Ryan Wall | 12 | Royston | 5:36.33 |
| 8 | 15 | Lazar Nemeth | 13 | St Felix Sch | 5:38.06 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 24 | Harvey Isle | 14 | West Norfolk | 5:26.60 |
| 2 | 26 | Kieran Birkett | 14 | Co St Albans | 5:25.89 |
| 3 | 28 | Mitchell Tamblin | 14 | Norwich Swan | 5:25.63 |
| 4 | 30 | Henry Jones | 14 | Modernian | 5:23.00 |
| 5 | 29 | James O'Connor | 14 | West Suffolk | 5:24.91 |
| 6 | 27 | Michael Connick | 14 | Deben | 5:25.70 |
| 7 | 25 | George De Voogt | 13 | C Beds SS | 5:26.25 |
| 8 | 23 | Zak Troman | 12 | Colchester | 5:26.60 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 32 | George Grice | 14 | Co Norwich | 5:22.80 |
| 2 | 34 | Matthew Monie | 14 | Co Cambridge | 5:21.01 |
| 3 | 36 | Mark Milburn | 14 | Colchester | 5:18.10 |
| 4 | 38 | Daniel Clayton | 13 | teamipswich | 5:15.60 |
| 5 | 37 | Denis Morine | 14 | Basildon Ph | 5:16.70 |
| 6 | 35 | Jenson Hurrell | 14 | Thurrock | 5:20.72 |
| 7 | 33 | Enzo Lim | 14 | Watford SC | 5:21.86 |
| 8 | 31 | Daniel McGuinness | 13 | Basildon Ph | 5:22.90 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 1 | 40 | Nikita Charykin | 13 | Thurrock | 5:09.59 |
| 2 | 42 | Christopher Williamson | 14 | Co Cambridge | 5:09.23 |
| 3 | 44 | James Clay | 14 | West Suffolk | 5:01.40 |
| 4 | 46 | Olivier Vedrenne | 14 | Co Norwich | 4:55.20 |
| 5 | 45 | Peter Soczewka | 14 | Hatfield | 5:00.76 |
| 6 | 43 | Jacob Stephen | 14 | Brentwood | 5:09.23 |
| 7 | 41 | Aidan Pilcher | 14 | teamipswich | 5:09.37 |
| 8 | 39 | Luke Oulds | 14 | Basildon Ph | 5:15.46 |