EVENT 402 Open/Male 09 /Over 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Cameron JAMISON | 9 | Lincoln TSA | 6:30.00 |
| 3 | 2 | Freddie HIRST | 10 | Grantham | 6:26.54 |
| 4 | 3 | Derrin BROCKLEBANK | 10 | Grantham | 6:26.11 |
| 5 | 4 | Alfie BLADES | 14 | Gainsborough | 6:21.01 |
| 6 | 5 | Daniel PEARSON | 36 | Boston | 6:05.89 |
| 7 | 6 | Jimmin BAO | 11 | Grantham | 6:05.51 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 8 | Leo BARNETT | 12 | Grantham | 5:56.81 |
| 2 | 10 | George LEONARD | 12 | Grantham | 5:44.95 |
| 3 | 12 | Logan BATES | 11 | Hucknall | 5:27.79 |
| 4 | 14 | Matthew TOMPKINSON | 15 | Louth | 4:40.56 |
| 5 | 13 | Luke DAYBELL | 15 | Grantham | 4:41.24 |
| 6 | 11 | Fabian KOLASA | 13 | Grantham | 5:42.00 |
| 7 | 9 | Henry WILLERTON | 11 | Skegness | 5:53.44 |
| 8 | 7 | Joshua KIM | 11 | Grantham | 6:05.00 |