EVENT 301 Open/Male 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 2 | Renars JERMAKS | 15 | Wellingboro | 7:00.00 |
| 4 | 4 | Michael FRASER | 13 | Hinckley | 6:38.10 |
| 5 | 3 | Harry STATHAM-GILL | 11 | Co Leicester | 6:44.50 |
| 6 | 1 | Oscar PAWLOWSKI | 10 | Corby | 7:38.10 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 6 | Aiden HORNE | 12 | Corby | 6:30.00 |
| 2 | 8 | George BROTHERSTON | 14 | Wellingboro | 6:19.30 |
| 3 | 10 | Arjun NAIR | 15 | Wellingboro | 6:05.32 |
| 4 | 12 | Jacob TYRRELL | 13 | Co Leicester | 5:52.60 |
| 5 | 11 | Jack PATERSON | 14 | Hinckley | 6:01.30 |
| 6 | 9 | Ted MARSHALL | 11 | Leic Sharks | 6:05.50 |
| 7 | 7 | Oliver SHAN | 12 | Leic Sharks | 6:27.40 |
| 8 | 5 | Jacob KING | 12 | Hinckley | 6:35.40 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 14 | Mason TRAYNOR | 11 | Co Leicester | 5:31.00 |
| 2 | 16 | Alex BARTLAM | 14 | Co Leicester | 5:26.20 |
| 3 | 18 | Ryan HEJRATY | 14 | Co Leicester | 5:14.50 |
| 4 | 20 | Frank BACON | 14 | Co Leicester | 5:04.90 |
| 5 | 19 | William KING | 16 | Hinckley | 5:08.10 |
| 6 | 17 | Callum SHIELLS | 16 | Leic Sharks | 5:23.80 |
| 7 | 15 | Kevin VARGA | 11 | Co Leicester | 5:27.10 |
| 8 | 13 | Joel WIFFEN | 15 | Corby | 5:46.00 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 22 | Mason ROUTLEDGE | 15 | Leic Sharks | 4:57.90 |
| 2 | 24 | Emerson-Blu GUPWELL | 14 | Co Leicester | 4:54.90 |
| 3 | 26 | Maxwell BURDETT | 12 | Co Leicester | 4:47.10 |
| 4 | 28 | Bobby PHILLIPS | 19 | Wellingboro | 4:28.20 |
| 5 | 27 | Finley DARE | 15 | Corby | 4:41.32 |
| 6 | 25 | Louis BOOKER | 17 | Wellingboro | 4:51.90 |
| 7 | 23 | Oliver HORNE | 15 | Corby | 4:57.72 |
| 8 | 21 | Cameron HIGGS | 14 | Newport Pag | 5:04.50 |