EVENT 51 Mens 15 Yrs/Over 400m IM - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 2 | 1 | Daniel Lyford | 17 | Carn Brea | 5:07.80 |
| 3 | 2 | Aslak Varela | 15 | Plymouth Lea | 5:05.66 |
| 4 | 3 | Marshall Fitchett | 16 | TigersharksW | 5:05.51 |
| 5 | 4 | Oscar North | 15 | Plymouth Lea | 5:03.27 |
| 6 | 5 | Luke Conder | 24 | Poole | 5:03.06 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 6 | Alec Farquharson | 15 | Paignton | 5:02.47 |
| 1 | 7 | Samuel Arrowsmith | 15 | Exeter City | 5:02.11 |
| 2 | 8 | Liam Openshaw | 15 | Poole | 5:01.08 |
| 3 | 9 | Harrison Jones | 19 | Chippenham | 4:59.30 |
| 4 | 10 | Sam Van Der Stroom | 15 | Mt Kelly | 4:59.29 |
| 5 | 11 | Joshua Frampton | 17 | South Dorset | 4:58.95 |
| 6 | 12 | Arno Turner | 17 | Southwold | 4:58.69 |
| 7 | 13 | Lucas Bennett | 16 | Co Bristol | 4:57.98 |
| 8 | 14 | Alexander Sargeant | 16 | Millfield | 4:57.70 |
| 9 | 15 | Miles Ward | 15 | Seagulls SC | 4:56.32 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 16 | Jackson Spry | 17 | Caradon | 4:55.92 |
| 1 | 17 | Henry Bennett | 18 | Southwold | 4:55.55 |
| 2 | 18 | Drew McGregor | 15 | S Bournem'th | 4:55.20 |
| 3 | 19 | Ra'eez Warley | 16 | Plymouth Lea | 4:54.60 |
| 4 | 20 | William Whitley | 17 | Mt Kelly | 4:53.04 |
| 5 | 21 | Jonah Silk | 15 | Co Bristol | 4:51.92 |
| 6 | 22 | Christian Tai | 17 | Bourmth Coll | 4:51.90 |
| 7 | 23 | Lucas Lawman | 16 | Team Bath AS | 4:51.90 |
| 8 | 24 | Ben Penhale | 15 | TauntonDeane | 4:51.40 |
| 9 | 25 | Dylan Gallagher | 15 | TauntonDeane | 4:48.80 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 27 | Ethan McNeil | 16 | Team Bath AS | 4:46.50 |
| 1 | 29 | Oliver Fairman | 16 | Poole | 4:42.80 |
| 2 | 31 | Donald Bisset | 17 | Gloucester | 4:40.27 |
| 3 | 33 | Michal Kotlewski | 24 | Bristol Hen | 4:39.17 |
| 4 | 35 | David Miller | 19 | Plymouth Lea | 4:32.61 |
| 5 | 34 | Jakob Goodman | 18 | Millfield | 4:33.40 |
| 6 | 32 | James King | 18 | Weston S M | 4:39.42 |
| 7 | 30 | Joseph Russell | 16 | Mt Kelly | 4:42.50 |
| 8 | 28 | James Bartley | 15 | Mt Kelly | 4:46.40 |
| 9 | 26 | Samuel Lawton | 17 | Co Bristol | 4:48.63 |