EVENT 204 Open/Male 13/15 Yrs 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Hugo Flikweert | 13 | Nene Valley | 6:10.89 |
| 4 | 3 | Alexander Stevenson | 14 | Nene Valley | 5:55.68 |
| 5 | 2 | Grayson Watford | 13 | Wellingboro | 6:01.80 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 5 | Percy Green | 13 | Corby | 5:30.04 |
| 3 | 7 | Harry Langstone | 14 | Kettering | 5:23.10 |
| 4 | 9 | Oliver Trenwith | 13 | Corby | 5:20.35 |
| 5 | 8 | Finley Stevenson | 15 | Corby | 5:21.16 |
| 6 | 6 | Kushal Mistry | 15 | Northampton | 5:24.53 |
| 7 | 4 | George Owen | 14 | Wellingboro | 5:52.20 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 11 | Noah Patterson | 13 | Corby | 5:19.18 |
| 2 | 13 | Cameron Hughes | 14 | Wellingboro | 5:17.70 |
| 3 | 15 | James Oscroft | 13 | Northampton | 5:11.30 |
| 4 | 17 | Seth Gillies | 15 | Northampton | 5:10.50 |
| 5 | 16 | Jacob Quennell | 13 | Northampton | 5:11.14 |
| 6 | 14 | Oscar Cutmore | 13 | Corby | 5:15.50 |
| 7 | 12 | Joseph Bird | 13 | Northampton | 5:18.30 |
| 8 | 10 | Sui Chun Yip | 14 | Corby | 5:19.29 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Tommy Knipes | 15 | Northampton | 5:07.70 |
| 2 | 21 | Lucas Poole | 14 | Northampton | 5:03.10 |
| 3 | 23 | Oscar Venn | 14 | Northampton | 4:55.80 |
| 4 | 25 | Daniel Mustata | 15 | Corby | 4:43.10 |
| 5 | 24 | Louis Pell | 15 | Northampton | 4:49.10 |
| 6 | 22 | Callum Taylor | 15 | Northampton | 5:02.00 |
| 7 | 20 | Benjamin White | 15 | Rushden | 5:05.61 |
| 8 | 18 | Elliott Thomson | 14 | Daventry | 5:09.00 |