EVENT 511 Mixed 1500m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 2 | Connie Flitton | 15 | Dunstable | 18:47.10 |
| 2 | 4 | Mia Nelson | 15 | Cheshunt | 18:40.03 |
| 3 | 6 | Ava Turner | 17 | Basildon Ph | 18:37.16 |
| 4 | 8 | Heidi King | 15 | Hemel Hemp | 18:26.86 |
| 5 | 7 | Isabel Thomas | 18 | Newmarket | 18:29.10 |
| 6 | 5 | Elizabeth Gore | 15 | Epping For't | 18:40.00 |
| 7 | 3 | Nina Allen | 15 | Newmarket | 18:41.20 |
| 8 | 1 | Ayla Zolfaghari | 15 | Epping For't | 18:51.70 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 10 | Jacob Wild | 15 | Newmarket | 18:19.70 |
| 2 | 12 | Olivia Croft | 15 | Cheshunt | 18:16.14 |
| 3 | 14 | Megan Barnicoat | 15 | Co Peterboro | 18:09.50 |
| 4 | 16 | Alice Weston | 20 | Watford SC | 18:04.46 |
| 5 | 15 | Heath Harrison | 15 | Stowmarket | 18:06.02 |
| 6 | 13 | Jack Canham | 15 | Team Luton | 18:15.30 |
| 7 | 11 | Ethan Woolsey | 15 | St Neot Swan | 18:19.31 |
| 8 | 9 | Jasmine Scott | 15 | Co St Albans | 18:24.90 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 18 | Summer Evason | 17 | Watford SC | 18:02.68 |
| 2 | 20 | Byron Miller | 15 | Colchester | 17:59.84 |
| 3 | 22 | Anabelle Kett | 17 | Co Peterboro | 17:58.22 |
| 4 | 24 | George Saunders | 16 | Co St Albans | 17:49.26 |
| 5 | 23 | Rex Harrison | 15 | Stowmarket | 17:54.69 |
| 6 | 21 | Amelia Saunders | 18 | Norwich Swan | 17:59.70 |
| 7 | 19 | Emma Cushion | 16 | Co Peterboro | 18:00.57 |
| 8 | 17 | Francesca Barber | 17 | Co Norwich | 18:03.94 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 26 | E Barth-Wehrenalp | 16 | Chelmsford | 17:47.73 |
| 2 | 28 | Lochlan Shaw | 16 | Flitwick | 17:41.60 |
| 3 | 30 | Joseph Subba | 15 | Co St Albans | 17:40.90 |
| 4 | 32 | Alexander Gaydon | 16 | Chelmsford | 17:36.49 |
| 5 | 31 | Ethan Wallis | 16 | Norwich Swan | 17:39.72 |
| 6 | 29 | Kye Harrington | 18 | West Norfolk | 17:41.07 |
| 7 | 27 | Amy Meyer | 17 | Biggleswade | 17:45.80 |
| 8 | 25 | Chloe Cranny | 15 | Epping For't | 17:47.85 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 34 | Tyler Stone | 16 | Co Norwich | 17:24.90 |
| 2 | 36 | Jacopo Agosti | 15 | Co Cambridge | 17:22.05 |
| 3 | 38 | Oliver Meier | 16 | Biggleswade | 17:18.91 |
| 4 | 40 | Xavier Zerban | 15 | Biggleswade | 17:17.64 |
| 5 | 39 | Lucas Day | 17 | Rochford | 17:18.53 |
| 6 | 37 | Kian Ptolomey | 16 | Putteridge | 17:20.47 |
| 7 | 35 | Max Lesner | 17 | Potters Bar | 17:24.84 |
| 8 | 33 | Charlie Stott | 17 | Co St Albans | 17:30.79 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 42 | Jed Millin | 18 | Stowmarket | 17:14.55 |
| 2 | 44 | Jasmine Hall | 16 | Basildon Ph | 17:04.60 |
| 3 | 46 | Janos Csepely | 15 | teamipswich | 16:46.90 |
| 4 | 48 | Jamie Wilson | 17 | West Norfolk | 16:34.78 |
| 5 | 47 | Oliver Fenwick | 17 | Hatfield | 16:46.45 |
| 6 | 45 | Luke Owens | 16 | Putteridge | 16:51.30 |
| 7 | 43 | Ryan Wimpenny | 16 | Cheshunt | 17:12.80 |
| 8 | 41 | Summer Smith | 15 | Basildon Ph | 17:17.32 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 50 | Zak Fellows | 17 | Co St Albans | 16:31.21 |
| 2 | 52 | Csanad Rehus | 17 | Co Peterboro | 16:28.26 |
| 3 | 54 | Ryan Wall | 19 | Co Cambridge | 16:16.40 |
| 4 | 56 | Conor Mint | 17 | Basildon Ph | 15:56.01 |
| 5 | 55 | Robert Fenner | 18 | Basildon Ph | 16:03.66 |
| 6 | 53 | Ethan Knights | 15 | teamipswich | 16:24.80 |
| 7 | 51 | Adam O'Neal | 18 | Bedford SS | 16:30.40 |
| 8 | 49 | Daniel Moyses | 20 | Co Peterboro | 16:32.87 |