EVENT 504 Mixed 1500m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 2 | Ben GORING-FARROW | 13 | Linslade | |
| 2 | 4 | Lucy ALEXANDER | 14 | Harpenden | |
| 3 | 7 | Joseph FINNERTY | 16 | Linslade | |
| 4 | 27 | Kirsty GREEN | 46 | Bushey | |
| 5 | 8 | Ned Peter ANDREWS | 12 | Haringey | |
| 6 | 6 | Charlotte STOCKS | 11 | Linslade | |
| 7 | 3 | Jack MAY | 12 | Linslade | |
| 8 | 1 | Chloe MATTHEWS | 12 | Linslade | |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 9 | Kevin NEZHA | 18 | Haringey | |
| 2 | 13 | Libby FLITTON | 11 | Dunstable | |
| 3 | 14 | Cerys LONG | 12 | Linslade | |
| 4 | 16 | Ewan LONG | 15 | Linslade | |
| 5 | 17 | Thomas FENWICK | 13 | Team Luton | |
| 6 | 15 | Harry FORSYTH | 16 | Linslade | |
| 7 | 12 | Callum RICHARDS | 13 | Harpenden | |
| 8 | 10 | Albert NEZHA | 12 | Haringey | |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 18 | Connie FLITTON | 13 | Dunstable | |
| 2 | 21 | Aaron RAWNSLEY | 12 | Harpenden | 22:14.10 |
| 3 | 23 | Emily HUDSZKY | 15 | Haringey | 20:41.30 |
| 4 | 26 | Alexander GAYDON | 13 | Colchester | 19:19.90 |
| 5 | 24 | Huseyin Yigit ILHAN | 14 | Haringey | 20:31.80 |
| 6 | 22 | Owain ROBERTS | 15 | Team Luton | 20:41.75 |
| 7 | 20 | Amy EDWARDS | 13 | Boldmere | 22:48.50 |
| 8 | 19 | Jack CANHAM | 12 | Team Luton | |