EVENT 204 Mixed 1500m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 2 | Stewart BUTLER | 13 | Dunstable | |
| 4 | 4 | Olivia COOPER | 15 | Dunstable | |
| 5 | 3 | Elissa NEO | 11 | Linslade | |
| 6 | 1 | Elizabeth STOCKS | 12 | Linslade | |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 6 | Evie ARMSTRONG | 12 | Dunstable | |
| 2 | 23 | Darcie CADER | 12 | Berkhamsted | 27:53.48 |
| 3 | 8 | Ben GORING-FARROW | 13 | Linslade | 22:51.90 |
| 4 | 11 | Zara CHAMORRO | 15 | Camden Swiss | 21:45.00 |
| 5 | 10 | Charlotte STOCKS | 12 | Linslade | 21:53.50 |
| 6 | 7 | Dewi FORDYCE | 11 | Berkhamsted | 26:37.28 |
| 7 | 22 | Inika SHARMA | 12 | Co Milton K | 28:00.00 |
| 8 | 5 | Samuel CHILDS | 11 | Berkhamsted | |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 13 | Evie TRAN | 14 | Camden Swiss | 20:45.38 |
| 2 | 15 | Owain ROBERTS | 15 | Team Luton | 19:39.50 |
| 3 | 17 | Perrin MA | 13 | Hatfield | 19:08.37 |
| 4 | 21 | Adam O'NEAL | 16 | Bedford SS | 17:28.20 |
| 5 | 20 | Leonardo DIALLO | 15 | Camden Swiss | 18:02.06 |
| 6 | 16 | Rose BENSON | 14 | Co Milton K | 19:09.17 |
| 7 | 14 | Luc BONFIGLIO | 13 | Camden Swiss | 20:00.21 |
| 8 | 12 | Alice BUCKINGHAM | 11 | Team Luton | 20:55.61 |