EVENT 301 Mens MC 10/18 Yrs 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 1 | A Moradianborougeni | 15 | S13 | Orion | 8:42.17 |
| 2 | 3 | Bruce Dee | 13 | S6 | Northampton | 7:23.20 |
| 3 | 5 | Alexander Hobbs | 14 | S7 | Mt Kelly | 7:02.93 |
| 4 | 7 | Sebastian Williams | 15 | S6 | Mt Kelly | 6:50.74 |
| 5 | 6 | William Whitehead | 14 | S8 | Eckington | 7:02.03 |
| 6 | 4 | Jamie Markall | 16 | S8 | Orion | 7:08.83 |
| 7 | 2 | Aiden Watkins | 16 | S6 | Co Manch Aq | 8:06.93 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 9 | Benny Romberg | 13 | S10 | Kingston Roy | 6:29.20 |
| 2 | 11 | Sam Downie | 13 | S9 | Musselburgh | 6:15.46 |
| 3 | 13 | Samuel Whearty | 17 | S9 | Colchester | 5:55.57 |
| 4 | 15 | Benjamin Pope | 15 | S8 | Havant & Wat | 5:44.78 |
| 5 | 14 | Cameron Hemphill | 16 | S10 | Carnegie | 5:47.27 |
| 6 | 12 | Toben Durrant | 14 | S13 | Co Cardiff | 6:13.99 |
| 7 | 10 | Jacob Chambers | 16 | S8 | Co Manch Aq | 6:28.88 |
| 8 | 8 | Matthew Davies | 15 | S10 | RomseyTotton | 6:48.29 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Cat | Club/Country | Time |
| 1 | 17 | Maximilian Tulloch | 14 | S9 | Chalfont | 5:31.47 |
| 2 | 19 | Roan Brennan | 13 | S9 | Basildon Ph | 5:14.56 |
| 3 | 21 | James Brown | 17 | S9 | Royal Wolv | 4:53.16 |
| 4 | 23 | Kieran Williams | 15 | S10 | Newquay | 4:35.69 |
| 5 | 22 | Benjamin Grainger | 16 | S10 | Mt Kelly | 4:39.90 |
| 6 | 20 | Charlie Coulam | 16 | S10 | Bridlington | 5:02.77 |
| 7 | 18 | Luke Batty | 14 | S9 | Bolton Metro | 5:21.73 |
| 8 | 16 | Balthazar Bradshaw | 13 | S10 | Brompton | 5:37.36 |