EVENT 301 Boys Open 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Alex Bartlam | 11 | Co Leicester | 7:21.79 |
| 4 | 2 | Harry Wilson | 11 | Northampton | 6:58.90 |
| 5 | 3 | Jack Webb | 10 | Northampton | 6:55.67 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 4 | Michal Wojcik | 12 | Northampton | 6:30.78 |
| 2 | 5 | Edward Oscroft | 12 | Northampton | 6:08.76 |
| 3 | 6 | Emerson-Blu Gupwell | 11 | Co Leicester | 6:08.10 |
| 4 | 7 | James Yates | 12 | Co Leicester | 6:07.63 |
| 5 | 8 | Matthew Taylor | 14 | Northampton | 6:05.60 |
| 6 | 9 | George Sarbutts | 15 | Northampton | 6:01.38 |
| 7 | 10 | Max Noon | 13 | Northampton | 6:00.59 |
| 8 | 11 | Joel Yates | 14 | Leicester Ne | 5:57.79 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 12 | Sebastian Casey | 11 | Co Leicester | 5:47.83 |
| 2 | 13 | Ethan Simmonds | 12 | Co Leicester | 5:45.28 |
| 3 | 14 | William Oxley | 11 | Co Leicester | 5:42.75 |
| 4 | 15 | Noah Tyers | 13 | Co Leicester | 5:40.50 |
| 5 | 16 | Tyrell Malcolm | 13 | Leicester Ne | 5:25.00 |
| 6 | 17 | Maximilian Talalayenko | 14 | Northampton | 5:17.45 |
| 7 | 18 | Edun Rowe | 13 | Northampton | 5:15.45 |
| 8 | 19 | Finlay Gibson | 13 | Co Leicester | 5:12.30 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 21 | Lewis Fitch | 14 | Co Leicester | 5:02.21 |
| 2 | 23 | Eden Wiles | 15 | Northampton | 4:45.67 |
| 3 | 25 | George Moore | 15 | Co Leicester | 4:25.24 |
| 4 | 27 | Sean McCann | 16 | Co Leicester | 4:12.10 |
| 5 | 26 | Charlie James | 15 | Co Leicester | 4:24.40 |
| 6 | 24 | Lewis Boyd | 13 | Co Leicester | 4:41.68 |
| 7 | 22 | Harry Fleet | 15 | Co Leicester | 5:00.98 |
| 8 | 20 | Bhaveshsingh Parmessur | 15 | Co Leicester | 5:11.53 |