EVENT 109 Mens Open 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 2 | Mason Bland | 15 | KingstonHull | 4:05.49 |
| 1 | 4 | Daniel Donovan | 16 | Elmbridge | 4:05.07 |
| 2 | 6 | Oscar North | 16 | Plymouth Lea | 4:04.40 |
| 3 | 8 | Daniel Gencas | 16 | Romford Town | 4:03.72 |
| 4 | 10 | Joseph Kingsland | 16 | Nova Cent'n | 4:03.65 |
| 5 | 9 | Joshua Skinner | 16 | Nova Cent'n | 4:03.71 |
| 6 | 7 | Liam Dawson | 14 | Nova Cent'n | 4:03.84 |
| 7 | 5 | Tyler Melbourne-Smith | 14 | Co Liverpool | 4:05.04 |
| 8 | 3 | Ethan Sutcliffe | 16 | Co Leeds | 4:05.08 |
| 9 | 1 | Theodore Thompson | 16 | Mt Kelly | 4:05.52 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 12 | Lewis Binning | 16 | Basildon Ph | 4:02.90 |
| 1 | 14 | Tyriese Smith | 15 | Co Liverpool | 4:02.58 |
| 2 | 16 | Daniel Kennedy | 15 | Co Leicester | 4:01.74 |
| 3 | 18 | Michael Klimaszewski | 15 | Hatfield | 4:01.43 |
| 4 | 20 | Joey Tippin | 16 | Co Leicester | 4:01.32 |
| 5 | 19 | Thomas Trebilcock | 16 | Plymouth Lea | 4:01.43 |
| 6 | 17 | Ewan Wilson | 17 | Co Salford | 4:01.48 |
| 7 | 15 | Freddie Ashley-Sparks | 17 | Plymouth Lea | 4:01.99 |
| 8 | 13 | Jevon Penny | 16 | Northampton | 4:02.64 |
| 9 | 11 | William Ellington | 16 | Millfield | 4:03.36 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 22 | Reuben Visda | 16 | Co Sheffield | 4:00.77 |
| 1 | 24 | Dalton Clapham | 16 | Co Leeds | 3:59.55 |
| 2 | 26 | Adam Hall | 18 | Loughboro Un | 3:59.30 |
| 3 | 28 | Samuel Tucker | 15 | Wycombe Dist | 3:58.97 |
| 4 | 30 | Jamie Owen | 17 | Wycombe Dist | 3:57.98 |
| 5 | 29 | Matthew Wright | 21 | Team Luton | 3:58.04 |
| 6 | 27 | Ralph Muncer | 18 | Co St Albans | 3:58.99 |
| 7 | 25 | Joseph Sadler | 16 | Nova Cent'n | 3:59.47 |
| 8 | 23 | Pierce Greening | 16 | Cockermouth | 3:59.56 |
| 9 | 21 | Joshua Gammon | 16 | Plymouth Lea | 4:00.78 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 33 | Daniel Esmeralda Rivas | 20 | Plymouth Lea | 3:57.50 |
| 1 | 37 | William Slawson | 22 | Wrekin Coll | 3:56.43 |
| 2 | 41 | Alexander Hindle | 17 | Co Birm'ham | 3:53.99 |
| 3 | 45 | William Bell | 17 | Co Leicester | 3:52.41 |
| 4 | 49 | Jakob Goodman | 19 | Millfield | 3:46.66 |
| 5 | 47 | Max Murphy | 19 | Loughboro Un | 3:51.35 |
| 6 | 43 | Samuel Osborne | 18 | Co Birm'ham | 3:53.16 |
| 7 | 39 | Jacob Davies | 17 | Co Birm'ham | 3:56.09 |
| 8 | 35 | Joseph Deighan | 16 | Millfield | 3:57.36 |
| 9 | 31 | Thomas Beamer | 17 | Co Leicester | 3:57.91 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 34 | Myles Robinson-Young | 17 | Co Peterboro | 3:57.43 |
| 1 | 38 | Davide Arioli | 17 | Millfield | 3:56.34 |
| 2 | 42 | Joshua Williams | 17 | Wycombe Dist | 3:53.20 |
| 3 | 46 | Nathan Wells | 21 | Loughboro Un | 3:51.87 |
| 4 | 50 | Jay Lelliott | 24 | Co Sheffield | 3:42.55 |
| 5 | 48 | Regan Lloyd | 22 | teamipswich | 3:47.30 |
| 6 | 44 | Alexander Bregazzi | 21 | Loughboro Un | 3:52.90 |
| 7 | 40 | Hector Pardoe | 18 | Ellesmere Co | 3:54.36 |
| 8 | 36 | Daniel Jenkins | 18 | Co Oxford | 3:57.28 |
| 9 | 32 | George Barber | 18 | Co Sheffield | 3:57.64 |